drivers/crypto/chelsio/chtls/chtls_io.c

   1 /*
   2  * Copyright (c) 2018 Chelsio Communications, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * Written by: Atul Gupta (atul.gupta@chelsio.com)
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/list.h>
  13 #include <linux/workqueue.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/timer.h>
  16 #include <linux/notifier.h>
  17 #include <linux/inetdevice.h>
  18 #include <linux/ip.h>
  19 #include <linux/tcp.h>
  20 #include <linux/sched/signal.h>
  21 #include <net/tcp.h>
  22 #include <net/busy_poll.h>
  23 #include <crypto/aes.h>
  24
  25 #include "chtls.h"
  26 #include "chtls_cm.h"
  27
  28 static bool is_tls_tx(struct chtls_sock *csk)
  29 {
  30         return csk->tlshws.txkey >= 0;
  31 }
  32
  33 static bool is_tls_rx(struct chtls_sock *csk)
  34 {
  35         return csk->tlshws.rxkey >= 0;
  36 }
  37
  38 static int data_sgl_len(const struct sk_buff *skb)
  39 {
  40         unsigned int cnt;
  41
  42         cnt = skb_shinfo(skb)->nr_frags;
  43         return sgl_len(cnt) * 8;
  44 }
  45
  46 static int nos_ivs(struct sock *sk, unsigned int size)
  47 {
  48         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
  49
  50         return DIV_ROUND_UP(size, csk->tlshws.mfs);
  51 }
  52
  53 static int set_ivs_imm(struct sock *sk, const struct sk_buff *skb)
  54 {
  55         int ivs_size = nos_ivs(sk, skb->len) * CIPHER_BLOCK_SIZE;
  56         int hlen = TLS_WR_CPL_LEN + data_sgl_len(skb);
  57
  58         if ((hlen + KEY_ON_MEM_SZ + ivs_size) <
  59             MAX_IMM_OFLD_TX_DATA_WR_LEN) {
  60                 ULP_SKB_CB(skb)->ulp.tls.iv = 1;
  61                 return 1;
  62         }
  63         ULP_SKB_CB(skb)->ulp.tls.iv = 0;
  64         return 0;
  65 }
  66
  67 static int max_ivs_size(struct sock *sk, int size)
  68 {
  69         return nos_ivs(sk, size) * CIPHER_BLOCK_SIZE;
  70 }
  71
  72 static int ivs_size(struct sock *sk, const struct sk_buff *skb)
  73 {
  74         return set_ivs_imm(sk, skb) ? (nos_ivs(sk, skb->len) *
  75                  CIPHER_BLOCK_SIZE) : 0;
  76 }
  77
  78 static int flowc_wr_credits(int nparams, int *flowclenp)
  79 {
  80         int flowclen16, flowclen;
  81
  82         flowclen = offsetof(struct fw_flowc_wr, mnemval[nparams]);
  83         flowclen16 = DIV_ROUND_UP(flowclen, 16);
  84         flowclen = flowclen16 * 16;
  85
  86         if (flowclenp)
  87                 *flowclenp = flowclen;
  88
  89         return flowclen16;
  90 }
  91
  92 static struct sk_buff *create_flowc_wr_skb(struct sock *sk,
  93                                            struct fw_flowc_wr *flowc,
  94                                            int flowclen)
  95 {
  96         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
  97         struct sk_buff *skb;
  98
  99         skb = alloc_skb(flowclen, GFP_ATOMIC);
 100         if (!skb)
 101                 return NULL;
 102
 103         memcpy(__skb_put(skb, flowclen), flowc, flowclen);
 104         skb_set_queue_mapping(skb, (csk->txq_idx << 1) | CPL_PRIORITY_DATA);
 105
 106         return skb;
 107 }
 108
 109 static int send_flowc_wr(struct sock *sk, struct fw_flowc_wr *flowc,
 110                          int flowclen)
 111 {
 112         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
 113         struct tcp_sock *tp = tcp_sk(sk);
 114         struct sk_buff *skb;
 115         int flowclen16;
 116         int ret;
 117
 118         flowclen16 = flowclen / 16;
 119
 120         if (csk_flag(sk, CSK_TX_DATA_SENT)) {
 121                 skb = create_flowc_wr_skb(sk, flowc, flowclen);
 122                 if (!skb)
 123                         return -ENOMEM;
 124
 125                 skb_entail(sk, skb,
 126                            ULPCB_FLAG_NO_HDR | ULPCB_FLAG_NO_APPEND);
 127                 return 0;
 128         }
 129
 130         ret = cxgb4_immdata_send(csk->egress_dev,
 131                                  csk->txq_idx,
 132                                  flowc, flowclen);
 133         if (!ret)
 134                 return flowclen16;
 135         skb = create_flowc_wr_skb(sk, flowc, flowclen);
 136         if (!skb)
 137                 return -ENOMEM;
 138         send_or_defer(sk, tp, skb, 0);
 139         return flowclen16;
 140 }
 141
 142 static u8 tcp_state_to_flowc_state(u8 state)
 143 {
 144         switch (state) {
 145         case TCP_ESTABLISHED:
 146                 return FW_FLOWC_MNEM_TCPSTATE_ESTABLISHED;
 147         case TCP_CLOSE_WAIT:
 148                 return FW_FLOWC_MNEM_TCPSTATE_CLOSEWAIT;
 149         case TCP_FIN_WAIT1:
 150                 return FW_FLOWC_MNEM_TCPSTATE_FINWAIT1;
 151         case TCP_CLOSING:
 152                 return FW_FLOWC_MNEM_TCPSTATE_CLOSING;
 153         case TCP_LAST_ACK:
 154                 return FW_FLOWC_MNEM_TCPSTATE_LASTACK;
 155         case TCP_FIN_WAIT2:
 156                 return FW_FLOWC_MNEM_TCPSTATE_FINWAIT2;
 157         }
 158
 159         return FW_FLOWC_MNEM_TCPSTATE_ESTABLISHED;
 160 }
 161
 162 int send_tx_flowc_wr(struct sock *sk, int compl,
 163                      u32 snd_nxt, u32 rcv_nxt)
 164 {
 165         struct flowc_packed {
 166                 struct fw_flowc_wr fc;
 167                 struct fw_flowc_mnemval mnemval[FW_FLOWC_MNEM_MAX];
 168         } __packed sflowc;
 169         int nparams, paramidx, flowclen16, flowclen;
 170         struct fw_flowc_wr *flowc;
 171         struct chtls_sock *csk;
 172         struct tcp_sock *tp;
 173
 174         csk = rcu_dereference_sk_user_data(sk);
 175         tp = tcp_sk(sk);
 176         memset(&sflowc, 0, sizeof(sflowc));
 177         flowc = &sflowc.fc;
 178
 179 #define FLOWC_PARAM(__m, __v) \
 180         do { \
 181                 flowc->mnemval[paramidx].mnemonic = FW_FLOWC_MNEM_##__m; \
 182                 flowc->mnemval[paramidx].val = cpu_to_be32(__v); \
 183                 paramidx++; \
 184         } while (0)
 185
 186         paramidx = 0;
 187
 188         FLOWC_PARAM(PFNVFN, FW_PFVF_CMD_PFN_V(csk->cdev->lldi->pf));
 189         FLOWC_PARAM(CH, csk->tx_chan);
 190         FLOWC_PARAM(PORT, csk->tx_chan);
 191         FLOWC_PARAM(IQID, csk->rss_qid);
 192         FLOWC_PARAM(SNDNXT, tp->snd_nxt);
 193         FLOWC_PARAM(RCVNXT, tp->rcv_nxt);
 194         FLOWC_PARAM(SNDBUF, csk->sndbuf);
 195         FLOWC_PARAM(MSS, tp->mss_cache);
 196         FLOWC_PARAM(TCPSTATE, tcp_state_to_flowc_state(sk->sk_state));
 197
 198         if (SND_WSCALE(tp))
 199                 FLOWC_PARAM(RCV_SCALE, SND_WSCALE(tp));
 200
 201         if (csk->ulp_mode == ULP_MODE_TLS)
 202                 FLOWC_PARAM(ULD_MODE, ULP_MODE_TLS);
 203
 204         if (csk->tlshws.fcplenmax)
 205                 FLOWC_PARAM(TXDATAPLEN_MAX, csk->tlshws.fcplenmax);
 206
 207         nparams = paramidx;
 208 #undef FLOWC_PARAM
 209
 210         flowclen16 = flowc_wr_credits(nparams, &flowclen);
 211         flowc->op_to_nparams =
 212                 cpu_to_be32(FW_WR_OP_V(FW_FLOWC_WR) |
 213                             FW_WR_COMPL_V(compl) |
 214                             FW_FLOWC_WR_NPARAMS_V(nparams));
 215         flowc->flowid_len16 = cpu_to_be32(FW_WR_LEN16_V(flowclen16) |
 216                                           FW_WR_FLOWID_V(csk->tid));
 217
 218         return send_flowc_wr(sk, flowc, flowclen);
 219 }
 220
 221 /* Copy IVs to WR */
 222 static int tls_copy_ivs(struct sock *sk, struct sk_buff *skb)
 223
 224 {
 225         struct chtls_sock *csk;
 226         unsigned char *iv_loc;
 227         struct chtls_hws *hws;
 228         unsigned char *ivs;
 229         u16 number_of_ivs;
 230         struct page *page;
 231         int err = 0;
 232
 233         csk = rcu_dereference_sk_user_data(sk);
 234         hws = &csk->tlshws;
 235         number_of_ivs = nos_ivs(sk, skb->len);
 236
 237         if (number_of_ivs > MAX_IVS_PAGE) {
 238                 pr_warn("MAX IVs in PAGE exceeded %d\n", number_of_ivs);
 239                 return -ENOMEM;
 240         }
 241
 242         /* generate the  IVs */
 243         ivs = kmalloc(number_of_ivs * CIPHER_BLOCK_SIZE, GFP_ATOMIC);
 244         if (!ivs)
 245                 return -ENOMEM;
 246         get_random_bytes(ivs, number_of_ivs * CIPHER_BLOCK_SIZE);
 247
 248         if (skb_ulp_tls_iv_imm(skb)) {
 249                 /* send the IVs as immediate data in the WR */
 250                 iv_loc = (unsigned char *)__skb_push(skb, number_of_ivs *
 251                                                 CIPHER_BLOCK_SIZE);
 252                 if (iv_loc)
 253                         memcpy(iv_loc, ivs, number_of_ivs * CIPHER_BLOCK_SIZE);
 254
 255                 hws->ivsize = number_of_ivs * CIPHER_BLOCK_SIZE;
 256         } else {
 257                 /* Send the IVs as sgls */
 258                 /* Already accounted IV DSGL for credits */
 259                 skb_shinfo(skb)->nr_frags--;
 260                 page = alloc_pages(sk->sk_allocation | __GFP_COMP, 0);
 261                 if (!page) {
 262                         pr_info("%s : Page allocation for IVs failed\n",
 263                                 __func__);
 264                         err = -ENOMEM;
 265                         goto out;
 266                 }
 267                 memcpy(page_address(page), ivs, number_of_ivs *
 268                        CIPHER_BLOCK_SIZE);
 269                 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, page, 0,
 270                                    number_of_ivs * CIPHER_BLOCK_SIZE);
 271                 hws->ivsize = 0;
 272         }
 273 out:
 274         kfree(ivs);
 275         return err;
 276 }
 277
 278 /* Copy Key to WR */
 279 static void tls_copy_tx_key(struct sock *sk, struct sk_buff *skb)
 280 {
 281         struct ulptx_sc_memrd *sc_memrd;
 282         struct chtls_sock *csk;
 283         struct chtls_dev *cdev;
 284         struct ulptx_idata *sc;
 285         struct chtls_hws *hws;
 286         u32 immdlen;
 287         int kaddr;
 288
 289         csk = rcu_dereference_sk_user_data(sk);
 290         hws = &csk->tlshws;
 291         cdev = csk->cdev;
 292
 293         immdlen = sizeof(*sc) + sizeof(*sc_memrd);
 294         kaddr = keyid_to_addr(cdev->kmap.start, hws->txkey);
 295         sc = (struct ulptx_idata *)__skb_push(skb, immdlen);
 296         if (sc) {
 297                 sc->cmd_more = htonl(ULPTX_CMD_V(ULP_TX_SC_NOOP));
 298                 sc->len = htonl(0);
 299                 sc_memrd = (struct ulptx_sc_memrd *)(sc + 1);
 300                 sc_memrd->cmd_to_len =
 301                                 htonl(ULPTX_CMD_V(ULP_TX_SC_MEMRD) |
 302                                 ULP_TX_SC_MORE_V(1) |
 303                                 ULPTX_LEN16_V(hws->keylen >> 4));
 304                 sc_memrd->addr = htonl(kaddr);
 305         }
 306 }
 307
 308 static u64 tlstx_incr_seqnum(struct chtls_hws *hws)
 309 {
 310         return hws->tx_seq_no++;
 311 }
 312
 313 static bool is_sg_request(const struct sk_buff *skb)
 314 {
 315         return skb->peeked ||
 316                 (skb->len > MAX_IMM_ULPTX_WR_LEN);
 317 }
 318
 319 /*
 320  * Returns true if an sk_buff carries urgent data.
 321  */
 322 static bool skb_urgent(struct sk_buff *skb)
 323 {
 324         return ULP_SKB_CB(skb)->flags & ULPCB_FLAG_URG;
 325 }
 326
 327 /* TLS content type for CPL SFO */
 328 static unsigned char tls_content_type(unsigned char content_type)
 329 {
 330         switch (content_type) {
 331         case TLS_HDR_TYPE_CCS:
 332                 return CPL_TX_TLS_SFO_TYPE_CCS;
 333         case TLS_HDR_TYPE_ALERT:
 334                 return CPL_TX_TLS_SFO_TYPE_ALERT;
 335         case TLS_HDR_TYPE_HANDSHAKE:
 336                 return CPL_TX_TLS_SFO_TYPE_HANDSHAKE;
 337         case TLS_HDR_TYPE_HEARTBEAT:
 338                 return CPL_TX_TLS_SFO_TYPE_HEARTBEAT;
 339         }
 340         return CPL_TX_TLS_SFO_TYPE_DATA;
 341 }
 342
 343 static void tls_tx_data_wr(struct sock *sk, struct sk_buff *skb,
 344                            int dlen, int tls_immd, u32 credits,
 345                            int expn, int pdus)
 346 {
 347         struct fw_tlstx_data_wr *req_wr;
 348         struct cpl_tx_tls_sfo *req_cpl;
 349         unsigned int wr_ulp_mode_force;
 350         struct tls_scmd *updated_scmd;
 351         unsigned char data_type;
 352         struct chtls_sock *csk;
 353         struct net_device *dev;
 354         struct chtls_hws *hws;
 355         struct tls_scmd *scmd;
 356         struct adapter *adap;
 357         unsigned char *req;
 358         int immd_len;
 359         int iv_imm;
 360         int len;
 361
 362         csk = rcu_dereference_sk_user_data(sk);
 363         iv_imm = skb_ulp_tls_iv_imm(skb);
 364         dev = csk->egress_dev;
 365         adap = netdev2adap(dev);
 366         hws = &csk->tlshws;
 367         scmd = &hws->scmd;
 368         len = dlen + expn;
 369
 370         dlen = (dlen < hws->mfs) ? dlen : hws->mfs;
 371         atomic_inc(&adap->chcr_stats.tls_pdu_tx);
 372
 373         updated_scmd = scmd;
 374         updated_scmd->seqno_numivs &= 0xffffff80;
 375         updated_scmd->seqno_numivs |= SCMD_NUM_IVS_V(pdus);
 376         hws->scmd = *updated_scmd;
 377
 378         req = (unsigned char *)__skb_push(skb, sizeof(struct cpl_tx_tls_sfo));
 379         req_cpl = (struct cpl_tx_tls_sfo *)req;
 380         req = (unsigned char *)__skb_push(skb, (sizeof(struct
 381                                 fw_tlstx_data_wr)));
 382
 383         req_wr = (struct fw_tlstx_data_wr *)req;
 384         immd_len = (tls_immd ? dlen : 0);
 385         req_wr->op_to_immdlen =
 386                 htonl(FW_WR_OP_V(FW_TLSTX_DATA_WR) |
 387                 FW_TLSTX_DATA_WR_COMPL_V(1) |
 388                 FW_TLSTX_DATA_WR_IMMDLEN_V(immd_len));
 389         req_wr->flowid_len16 = htonl(FW_TLSTX_DATA_WR_FLOWID_V(csk->tid) |
 390                                      FW_TLSTX_DATA_WR_LEN16_V(credits));
 391         wr_ulp_mode_force = TX_ULP_MODE_V(ULP_MODE_TLS);
 392
 393         if (is_sg_request(skb))
 394                 wr_ulp_mode_force |= FW_OFLD_TX_DATA_WR_ALIGNPLD_F |
 395                         ((tcp_sk(sk)->nonagle & TCP_NAGLE_OFF) ? 0 :
 396                         FW_OFLD_TX_DATA_WR_SHOVE_F);
 397
 398         req_wr->lsodisable_to_flags =
 399                         htonl(TX_ULP_MODE_V(ULP_MODE_TLS) |
 400                               FW_OFLD_TX_DATA_WR_URGENT_V(skb_urgent(skb)) |
 401                               T6_TX_FORCE_F | wr_ulp_mode_force |
 402                               TX_SHOVE_V((!csk_flag(sk, CSK_TX_MORE_DATA)) &&
 403                                          skb_queue_empty(&csk->txq)));
 404
 405         req_wr->ctxloc_to_exp =
 406                         htonl(FW_TLSTX_DATA_WR_NUMIVS_V(pdus) |
 407                               FW_TLSTX_DATA_WR_EXP_V(expn) |
 408                               FW_TLSTX_DATA_WR_CTXLOC_V(CHTLS_KEY_CONTEXT_DDR) |
 409                               FW_TLSTX_DATA_WR_IVDSGL_V(!iv_imm) |
 410                               FW_TLSTX_DATA_WR_KEYSIZE_V(hws->keylen >> 4));
 411
 412         /* Fill in the length */
 413         req_wr->plen = htonl(len);
 414         req_wr->mfs = htons(hws->mfs);
 415         req_wr->adjustedplen_pkd =
 416                 htons(FW_TLSTX_DATA_WR_ADJUSTEDPLEN_V(hws->adjustlen));
 417         req_wr->expinplenmax_pkd =
 418                 htons(FW_TLSTX_DATA_WR_EXPINPLENMAX_V(hws->expansion));
 419         req_wr->pdusinplenmax_pkd =
 420                 FW_TLSTX_DATA_WR_PDUSINPLENMAX_V(hws->pdus);
 421         req_wr->r10 = 0;
 422
 423         data_type = tls_content_type(ULP_SKB_CB(skb)->ulp.tls.type);
 424         req_cpl->op_to_seg_len = htonl(CPL_TX_TLS_SFO_OPCODE_V(CPL_TX_TLS_SFO) |
 425                                        CPL_TX_TLS_SFO_DATA_TYPE_V(data_type) |
 426                                        CPL_TX_TLS_SFO_CPL_LEN_V(2) |
 427                                        CPL_TX_TLS_SFO_SEG_LEN_V(dlen));
 428         req_cpl->pld_len = htonl(len - expn);
 429
 430         req_cpl->type_protover = htonl(CPL_TX_TLS_SFO_TYPE_V
 431                 ((data_type == CPL_TX_TLS_SFO_TYPE_HEARTBEAT) ?
 432                 TLS_HDR_TYPE_HEARTBEAT : 0) |
 433                 CPL_TX_TLS_SFO_PROTOVER_V(0));
 434
 435         /* create the s-command */
 436         req_cpl->r1_lo = 0;
 437         req_cpl->seqno_numivs  = cpu_to_be32(hws->scmd.seqno_numivs);
 438         req_cpl->ivgen_hdrlen = cpu_to_be32(hws->scmd.ivgen_hdrlen);
 439         req_cpl->scmd1 = cpu_to_be64(tlstx_incr_seqnum(hws));
 440 }
 441
 442 /*
 443  * Calculate the TLS data expansion size
 444  */
 445 static int chtls_expansion_size(struct sock *sk, int data_len,
 446                                 int fullpdu,
 447                                 unsigned short *pducnt)
 448 {
 449         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
 450         struct chtls_hws *hws = &csk->tlshws;
 451         struct tls_scmd *scmd = &hws->scmd;
 452         int fragsize = hws->mfs;
 453         int expnsize = 0;
 454         int fragleft;
 455         int fragcnt;
 456         int expppdu;
 457
 458         if (SCMD_CIPH_MODE_G(scmd->seqno_numivs) ==
 459             SCMD_CIPH_MODE_AES_GCM) {
 460                 expppdu = GCM_TAG_SIZE + AEAD_EXPLICIT_DATA_SIZE +
 461                           TLS_HEADER_LENGTH;
 462
 463                 if (fullpdu) {
 464                         *pducnt = data_len / (expppdu + fragsize);
 465                         if (*pducnt > 32)
 466                                 *pducnt = 32;
 467                         else if (!*pducnt)
 468                                 *pducnt = 1;
 469                         expnsize = (*pducnt) * expppdu;
 470                         return expnsize;
 471                 }
 472                 fragcnt = (data_len / fragsize);
 473                 expnsize =  fragcnt * expppdu;
 474                 fragleft = data_len % fragsize;
 475                 if (fragleft > 0)
 476                         expnsize += expppdu;
 477         }
 478         return expnsize;
 479 }
 480
 481 /* WR with IV, KEY and CPL SFO added */
 482 static void make_tlstx_data_wr(struct sock *sk, struct sk_buff *skb,
 483                                int tls_tx_imm, int tls_len, u32 credits)
 484 {
 485         unsigned short pdus_per_ulp = 0;
 486         struct chtls_sock *csk;
 487         struct chtls_hws *hws;
 488         int expn_sz;
 489         int pdus;
 490
 491         csk = rcu_dereference_sk_user_data(sk);
 492         hws = &csk->tlshws;
 493         pdus = DIV_ROUND_UP(tls_len, hws->mfs);
 494         expn_sz = chtls_expansion_size(sk, tls_len, 0, NULL);
 495         if (!hws->compute) {
 496                 hws->expansion = chtls_expansion_size(sk,
 497                                                       hws->fcplenmax,
 498                                                       1, &pdus_per_ulp);
 499                 hws->pdus = pdus_per_ulp;
 500                 hws->adjustlen = hws->pdus *
 501                         ((hws->expansion / hws->pdus) + hws->mfs);
 502                 hws->compute = 1;
 503         }
 504         if (tls_copy_ivs(sk, skb))
 505                 return;
 506         tls_copy_tx_key(sk, skb);
 507         tls_tx_data_wr(sk, skb, tls_len, tls_tx_imm, credits, expn_sz, pdus);
 508         hws->tx_seq_no += (pdus - 1);
 509 }
 510
 511 static void make_tx_data_wr(struct sock *sk, struct sk_buff *skb,
 512                             unsigned int immdlen, int len,
 513                             u32 credits, u32 compl)
 514 {
 515         struct fw_ofld_tx_data_wr *req;
 516         unsigned int wr_ulp_mode_force;
 517         struct chtls_sock *csk;
 518         unsigned int opcode;
 519
 520         csk = rcu_dereference_sk_user_data(sk);
 521         opcode = FW_OFLD_TX_DATA_WR;
 522
 523         req = (struct fw_ofld_tx_data_wr *)__skb_push(skb, sizeof(*req));
 524         req->op_to_immdlen = htonl(WR_OP_V(opcode) |
 525                                 FW_WR_COMPL_V(compl) |
 526                                 FW_WR_IMMDLEN_V(immdlen));
 527         req->flowid_len16 = htonl(FW_WR_FLOWID_V(csk->tid) |
 528                                 FW_WR_LEN16_V(credits));
 529
 530         wr_ulp_mode_force = TX_ULP_MODE_V(csk->ulp_mode);
 531         if (is_sg_request(skb))
 532                 wr_ulp_mode_force |= FW_OFLD_TX_DATA_WR_ALIGNPLD_F |
 533                         ((tcp_sk(sk)->nonagle & TCP_NAGLE_OFF) ? 0 :
 534                                 FW_OFLD_TX_DATA_WR_SHOVE_F);
 535
 536         req->tunnel_to_proxy = htonl(wr_ulp_mode_force |
 537                         FW_OFLD_TX_DATA_WR_URGENT_V(skb_urgent(skb)) |
 538                         FW_OFLD_TX_DATA_WR_SHOVE_V((!csk_flag
 539                                         (sk, CSK_TX_MORE_DATA)) &&
 540                                          skb_queue_empty(&csk->txq)));
 541         req->plen = htonl(len);
 542 }
 543
 544 static int chtls_wr_size(struct chtls_sock *csk, const struct sk_buff *skb,
 545                          bool size)
 546 {
 547         int wr_size;
 548
 549         wr_size = TLS_WR_CPL_LEN;
 550         wr_size += KEY_ON_MEM_SZ;
 551         wr_size += ivs_size(csk->sk, skb);
 552
 553         if (size)
 554                 return wr_size;
 555
 556         /* frags counted for IV dsgl */
 557         if (!skb_ulp_tls_iv_imm(skb))
 558                 skb_shinfo(skb)->nr_frags++;
 559
 560         return wr_size;
 561 }
 562
 563 static bool is_ofld_imm(struct chtls_sock *csk, const struct sk_buff *skb)
 564 {
 565         int length = skb->len;
 566
 567         if (skb->peeked || skb->len > MAX_IMM_ULPTX_WR_LEN)
 568                 return false;
 569
 570         if (likely(ULP_SKB_CB(skb)->flags & ULPCB_FLAG_NEED_HDR)) {
 571                 /* Check TLS header len for Immediate */
 572                 if (csk->ulp_mode == ULP_MODE_TLS &&
 573                     skb_ulp_tls_inline(skb))
 574                         length += chtls_wr_size(csk, skb, true);
 575                 else
 576                         length += sizeof(struct fw_ofld_tx_data_wr);
 577
 578                 return length <= MAX_IMM_OFLD_TX_DATA_WR_LEN;
 579         }
 580         return true;
 581 }
 582
 583 static unsigned int calc_tx_flits(const struct sk_buff *skb,
 584                                   unsigned int immdlen)
 585 {
 586         unsigned int flits, cnt;
 587
 588         flits = immdlen / 8;   /* headers */
 589         cnt = skb_shinfo(skb)->nr_frags;
 590         if (skb_tail_pointer(skb) != skb_transport_header(skb))
 591                 cnt++;
 592         return flits + sgl_len(cnt);
 593 }
 594
 595 static void arp_failure_discard(void *handle, struct sk_buff *skb)
 596 {
 597         kfree_skb(skb);
 598 }
 599
 600 int chtls_push_frames(struct chtls_sock *csk, int comp)
 601 {
 602         struct chtls_hws *hws = &csk->tlshws;
 603         struct tcp_sock *tp;
 604         struct sk_buff *skb;
 605         int total_size = 0;
 606         struct sock *sk;
 607         int wr_size;
 608
 609         wr_size = sizeof(struct fw_ofld_tx_data_wr);
 610         sk = csk->sk;
 611         tp = tcp_sk(sk);
 612
 613         if (unlikely(sk_in_state(sk, TCPF_SYN_SENT | TCPF_CLOSE)))
 614                 return 0;
 615
 616         if (unlikely(csk_flag(sk, CSK_ABORT_SHUTDOWN)))
 617                 return 0;
 618
 619         while (csk->wr_credits && (skb = skb_peek(&csk->txq)) &&
 620                (!(ULP_SKB_CB(skb)->flags & ULPCB_FLAG_HOLD) ||
 621                 skb_queue_len(&csk->txq) > 1)) {
 622                 unsigned int credit_len = skb->len;
 623                 unsigned int credits_needed;
 624                 unsigned int completion = 0;
 625                 int tls_len = skb->len;/* TLS data len before IV/key */
 626                 unsigned int immdlen;
 627                 int len = skb->len;    /* length [ulp bytes] inserted by hw */
 628                 int flowclen16 = 0;
 629                 int tls_tx_imm = 0;
 630
 631                 immdlen = skb->len;
 632                 if (!is_ofld_imm(csk, skb)) {
 633                         immdlen = skb_transport_offset(skb);
 634                         if (skb_ulp_tls_inline(skb))
 635                                 wr_size = chtls_wr_size(csk, skb, false);
 636                         credit_len = 8 * calc_tx_flits(skb, immdlen);
 637                 } else {
 638                         if (skb_ulp_tls_inline(skb)) {
 639                                 wr_size = chtls_wr_size(csk, skb, false);
 640                                 tls_tx_imm = 1;
 641                         }
 642                 }
 643                 if (likely(ULP_SKB_CB(skb)->flags & ULPCB_FLAG_NEED_HDR))
 644                         credit_len += wr_size;
 645                 credits_needed = DIV_ROUND_UP(credit_len, 16);
 646                 if (!csk_flag_nochk(csk, CSK_TX_DATA_SENT)) {
 647                         flowclen16 = send_tx_flowc_wr(sk, 1, tp->snd_nxt,
 648                                                       tp->rcv_nxt);
 649                         if (flowclen16 <= 0)
 650                                 break;
 651                         csk->wr_credits -= flowclen16;
 652                         csk->wr_unacked += flowclen16;
 653                         csk->wr_nondata += flowclen16;
 654                         csk_set_flag(csk, CSK_TX_DATA_SENT);
 655                 }
 656
 657                 if (csk->wr_credits < credits_needed) {
 658                         if (skb_ulp_tls_inline(skb) &&
 659                             !skb_ulp_tls_iv_imm(skb))
 660                                 skb_shinfo(skb)->nr_frags--;
 661                         break;
 662                 }
 663
 664                 __skb_unlink(skb, &csk->txq);
 665                 skb_set_queue_mapping(skb, (csk->txq_idx << 1) |
 666                                       CPL_PRIORITY_DATA);
 667                 if (hws->ofld)
 668                         hws->txqid = (skb->queue_mapping >> 1);
 669                 skb->csum = (__force __wsum)(credits_needed + csk->wr_nondata);
 670                 csk->wr_credits -= credits_needed;
 671                 csk->wr_unacked += credits_needed;
 672                 csk->wr_nondata = 0;
 673                 enqueue_wr(csk, skb);
 674
 675                 if (likely(ULP_SKB_CB(skb)->flags & ULPCB_FLAG_NEED_HDR)) {
 676                         if ((comp && csk->wr_unacked == credits_needed) ||
 677                             (ULP_SKB_CB(skb)->flags & ULPCB_FLAG_COMPL) ||
 678                             csk->wr_unacked >= csk->wr_max_credits / 2) {
 679                                 completion = 1;
 680                                 csk->wr_unacked = 0;
 681                         }
 682                         if (skb_ulp_tls_inline(skb))
 683                                 make_tlstx_data_wr(sk, skb, tls_tx_imm,
 684                                                    tls_len, credits_needed);
 685                         else
 686                                 make_tx_data_wr(sk, skb, immdlen, len,
 687                                                 credits_needed, completion);
 688                         tp->snd_nxt += len;
 689                         tp->lsndtime = tcp_time_stamp(tp);
 690                         if (completion)
 691                                 ULP_SKB_CB(skb)->flags &= ~ULPCB_FLAG_NEED_HDR;
 692                 } else {
 693                         struct cpl_close_con_req *req = cplhdr(skb);
 694                         unsigned int cmd  = CPL_OPCODE_G(ntohl
 695                                              (OPCODE_TID(req)));
 696
 697                         if (cmd == CPL_CLOSE_CON_REQ)
 698                                 csk_set_flag(csk,
 699                                              CSK_CLOSE_CON_REQUESTED);
 700
 701                         if ((ULP_SKB_CB(skb)->flags & ULPCB_FLAG_COMPL) &&
 702                             (csk->wr_unacked >= csk->wr_max_credits / 2)) {
 703                                 req->wr.wr_hi |= htonl(FW_WR_COMPL_F);
 704                                 csk->wr_unacked = 0;
 705                         }
 706                 }
 707                 total_size += skb->truesize;
 708                 if (ULP_SKB_CB(skb)->flags & ULPCB_FLAG_BARRIER)
 709                         csk_set_flag(csk, CSK_TX_WAIT_IDLE);
 710                 t4_set_arp_err_handler(skb, NULL, arp_failure_discard);
 711                 cxgb4_l2t_send(csk->egress_dev, skb, csk->l2t_entry);
 712         }
 713         sk->sk_wmem_queued -= total_size;
 714         return total_size;
 715 }
 716
 717 static void mark_urg(struct tcp_sock *tp, int flags,
 718                      struct sk_buff *skb)
 719 {
 720         if (unlikely(flags & MSG_OOB)) {
 721                 tp->snd_up = tp->write_seq;
 722                 ULP_SKB_CB(skb)->flags = ULPCB_FLAG_URG |
 723                                          ULPCB_FLAG_BARRIER |
 724                                          ULPCB_FLAG_NO_APPEND |
 725                                          ULPCB_FLAG_NEED_HDR;
 726         }
 727 }
 728
 729 /*
 730  * Returns true if a connection should send more data to TCP engine
 731  */
 732 static bool should_push(struct sock *sk)
 733 {
 734         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
 735         struct chtls_dev *cdev = csk->cdev;
 736         struct tcp_sock *tp = tcp_sk(sk);
 737
 738         /*
 739          * If we've released our offload resources there's nothing to do ...
 740          */
 741         if (!cdev)
 742                 return false;
 743
 744         /*
 745          * If there aren't any work requests in flight, or there isn't enough
 746          * data in flight, or Nagle is off then send the current TX_DATA
 747          * otherwise hold it and wait to accumulate more data.
 748          */
 749         return csk->wr_credits == csk->wr_max_credits ||
 750                 (tp->nonagle & TCP_NAGLE_OFF);
 751 }
 752
 753 /*
 754  * Returns true if a TCP socket is corked.
 755  */
 756 static bool corked(const struct tcp_sock *tp, int flags)
 757 {
 758         return (flags & MSG_MORE) || (tp->nonagle & TCP_NAGLE_CORK);
 759 }
 760
 761 /*
 762  * Returns true if a send should try to push new data.
 763  */
 764 static bool send_should_push(struct sock *sk, int flags)
 765 {
 766         return should_push(sk) && !corked(tcp_sk(sk), flags);
 767 }
 768
 769 void chtls_tcp_push(struct sock *sk, int flags)
 770 {
 771         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
 772         int qlen = skb_queue_len(&csk->txq);
 773
 774         if (likely(qlen)) {
 775                 struct sk_buff *skb = skb_peek_tail(&csk->txq);
 776                 struct tcp_sock *tp = tcp_sk(sk);
 777
 778                 mark_urg(tp, flags, skb);
 779
 780                 if (!(ULP_SKB_CB(skb)->flags & ULPCB_FLAG_NO_APPEND) &&
 781                     corked(tp, flags)) {
 782                         ULP_SKB_CB(skb)->flags |= ULPCB_FLAG_HOLD;
 783                         return;
 784                 }
 785
 786                 ULP_SKB_CB(skb)->flags &= ~ULPCB_FLAG_HOLD;
 787                 if (qlen == 1 &&
 788                     ((ULP_SKB_CB(skb)->flags & ULPCB_FLAG_NO_APPEND) ||
 789                      should_push(sk)))
 790                         chtls_push_frames(csk, 1);
 791         }
 792 }
 793
 794 /*
 795  * Calculate the size for a new send sk_buff.  It's maximum size so we can
 796  * pack lots of data into it, unless we plan to send it immediately, in which
 797  * case we size it more tightly.
 798  *
 799  * Note: we don't bother compensating for MSS < PAGE_SIZE because it doesn't
 800  * arise in normal cases and when it does we are just wasting memory.
 801  */
 802 static int select_size(struct sock *sk, int io_len, int flags, int len)
 803 {
 804         const int pgbreak = SKB_MAX_HEAD(len);
 805
 806         /*
 807          * If the data wouldn't fit in the main body anyway, put only the
 808          * header in the main body so it can use immediate data and place all
 809          * the payload in page fragments.
 810          */
 811         if (io_len > pgbreak)
 812                 return 0;
 813
 814         /*
 815          * If we will be accumulating payload get a large main body.
 816          */
 817         if (!send_should_push(sk, flags))
 818                 return pgbreak;
 819
 820         return io_len;
 821 }
 822
 823 void skb_entail(struct sock *sk, struct sk_buff *skb, int flags)
 824 {
 825         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
 826         struct tcp_sock *tp = tcp_sk(sk);
 827
 828         ULP_SKB_CB(skb)->seq = tp->write_seq;
 829         ULP_SKB_CB(skb)->flags = flags;
 830         __skb_queue_tail(&csk->txq, skb);
 831         sk->sk_wmem_queued += skb->truesize;
 832
 833         if (TCP_PAGE(sk) && TCP_OFF(sk)) {
 834                 put_page(TCP_PAGE(sk));
 835                 TCP_PAGE(sk) = NULL;
 836                 TCP_OFF(sk) = 0;
 837         }
 838 }
 839
 840 static struct sk_buff *get_tx_skb(struct sock *sk, int size)
 841 {
 842         struct sk_buff *skb;
 843
 844         skb = alloc_skb(size + TX_HEADER_LEN, sk->sk_allocation);
 845         if (likely(skb)) {
 846                 skb_reserve(skb, TX_HEADER_LEN);
 847                 skb_entail(sk, skb, ULPCB_FLAG_NEED_HDR);
 848                 skb_reset_transport_header(skb);
 849         }
 850         return skb;
 851 }
 852
 853 static struct sk_buff *get_record_skb(struct sock *sk, int size, bool zcopy)
 854 {
 855         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
 856         struct sk_buff *skb;
 857
 858         skb = alloc_skb(((zcopy ? 0 : size) + TX_TLSHDR_LEN +
 859                         KEY_ON_MEM_SZ + max_ivs_size(sk, size)),
 860                         sk->sk_allocation);
 861         if (likely(skb)) {
 862                 skb_reserve(skb, (TX_TLSHDR_LEN +
 863                             KEY_ON_MEM_SZ + max_ivs_size(sk, size)));
 864                 skb_entail(sk, skb, ULPCB_FLAG_NEED_HDR);
 865                 skb_reset_transport_header(skb);
 866                 ULP_SKB_CB(skb)->ulp.tls.ofld = 1;
 867                 ULP_SKB_CB(skb)->ulp.tls.type = csk->tlshws.type;
 868         }
 869         return skb;
 870 }
 871
 872 static void tx_skb_finalize(struct sk_buff *skb)
 873 {
 874         struct ulp_skb_cb *cb = ULP_SKB_CB(skb);
 875
 876         if (!(cb->flags & ULPCB_FLAG_NO_HDR))
 877                 cb->flags = ULPCB_FLAG_NEED_HDR;
 878         cb->flags |= ULPCB_FLAG_NO_APPEND;
 879 }
 880
 881 static void push_frames_if_head(struct sock *sk)
 882 {
 883         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
 884
 885         if (skb_queue_len(&csk->txq) == 1)
 886                 chtls_push_frames(csk, 1);
 887 }
 888
 889 static int chtls_skb_copy_to_page_nocache(struct sock *sk,
 890                                           struct iov_iter *from,
 891                                           struct sk_buff *skb,
 892                                           struct page *page,
 893                                           int off, int copy)
 894 {
 895         int err;
 896
 897         err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) +
 898                                        off, copy, skb->len);
 899         if (err)
 900                 return err;
 901
 902         skb->len             += copy;
 903         skb->data_len        += copy;
 904         skb->truesize        += copy;
 905         sk->sk_wmem_queued   += copy;
 906         return 0;
 907 }
 908
 909 /* Read TLS header to find content type and data length */
 910 static int tls_header_read(struct tls_hdr *thdr, struct iov_iter *from)
 911 {
 912         if (copy_from_iter(thdr, sizeof(*thdr), from) != sizeof(*thdr))
 913                 return -EFAULT;
 914         return (__force int)cpu_to_be16(thdr->length);
 915 }
 916
 917 static int csk_mem_free(struct chtls_dev *cdev, struct sock *sk)
 918 {
 919         return (cdev->max_host_sndbuf - sk->sk_wmem_queued);
 920 }
 921
 922 static int csk_wait_memory(struct chtls_dev *cdev,
 923                            struct sock *sk, long *timeo_p)
 924 {
 925         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 926         int sndbuf, err = 0;
 927         long current_timeo;
 928         long vm_wait = 0;
 929         bool noblock;
 930
 931         current_timeo = *timeo_p;
 932         noblock = (*timeo_p ? false : true);
 933         sndbuf = cdev->max_host_sndbuf;
 934         if (csk_mem_free(cdev, sk)) {
 935                 current_timeo = (prandom_u32() % (HZ / 5)) + 2;
 936                 vm_wait = (prandom_u32() % (HZ / 5)) + 2;
 937         }
 938
 939         add_wait_queue(sk_sleep(sk), &wait);
 940         while (1) {
 941                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 942
 943                 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 944                         goto do_error;
 945                 if (!*timeo_p) {
 946                         if (noblock)
 947                                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 948                         goto do_nonblock;
 949                 }
 950                 if (signal_pending(current))
 951                         goto do_interrupted;
 952                 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 953                 if (csk_mem_free(cdev, sk) && !vm_wait)
 954                         break;
 955
 956                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 957                 sk->sk_write_pending++;
 958                 sk_wait_event(sk, &current_timeo, sk->sk_err ||
 959                               (sk->sk_shutdown & SEND_SHUTDOWN) ||
 960                               (csk_mem_free(cdev, sk) && !vm_wait), &wait);
 961                 sk->sk_write_pending--;
 962
 963                 if (vm_wait) {
 964                         vm_wait -= current_timeo;
 965                         current_timeo = *timeo_p;
 966                         if (current_timeo != MAX_SCHEDULE_TIMEOUT) {
 967                                 current_timeo -= vm_wait;
 968                                 if (current_timeo < 0)
 969                                         current_timeo = 0;
 970                         }
 971                         vm_wait = 0;
 972                 }
 973                 *timeo_p = current_timeo;
 974         }
 975 do_rm_wq:
 976         remove_wait_queue(sk_sleep(sk), &wait);
 977         return err;
 978 do_error:
 979         err = -EPIPE;
 980         goto do_rm_wq;
 981 do_nonblock:
 982         err = -EAGAIN;
 983         goto do_rm_wq;
 984 do_interrupted:
 985         err = sock_intr_errno(*timeo_p);
 986         goto do_rm_wq;
 987 }
 988
 989 int chtls_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 990 {
 991         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
 992         struct chtls_dev *cdev = csk->cdev;
 993         struct tcp_sock *tp = tcp_sk(sk);
 994         struct sk_buff *skb;
 995         int mss, flags, err;
 996         int recordsz = 0;
 997         int copied = 0;
 998         int hdrlen = 0;
 999         long timeo;
1000
1001         lock_sock(sk);
1002         flags = msg->msg_flags;
1003         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1004
1005         if (!sk_in_state(sk, TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) {
1006                 err = sk_stream_wait_connect(sk, &timeo);
1007                 if (err)
1008                         goto out_err;
1009         }
1010
1011         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1012         err = -EPIPE;
1013         if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1014                 goto out_err;
1015
1016         mss = csk->mss;
1017         csk_set_flag(csk, CSK_TX_MORE_DATA);
1018
1019         while (msg_data_left(msg)) {
1020                 int copy = 0;
1021
1022                 skb = skb_peek_tail(&csk->txq);
1023                 if (skb) {
1024                         copy = mss - skb->len;
1025                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1026                 }
1027                 if (!csk_mem_free(cdev, sk))
1028                         goto wait_for_sndbuf;
1029
1030                 if (is_tls_tx(csk) && !csk->tlshws.txleft) {
1031                         struct tls_hdr hdr;
1032
1033                         recordsz = tls_header_read(&hdr, &msg->msg_iter);
1034                         size -= TLS_HEADER_LENGTH;
1035                         hdrlen += TLS_HEADER_LENGTH;
1036                         csk->tlshws.txleft = recordsz;
1037                         csk->tlshws.type = hdr.type;
1038                         if (skb)
1039                                 ULP_SKB_CB(skb)->ulp.tls.type = hdr.type;
1040                 }
1041
1042                 if (!skb || (ULP_SKB_CB(skb)->flags & ULPCB_FLAG_NO_APPEND) ||
1043                     copy <= 0) {
1044 new_buf:
1045                         if (skb) {
1046                                 tx_skb_finalize(skb);
1047                                 push_frames_if_head(sk);
1048                         }
1049
1050                         if (is_tls_tx(csk)) {
1051                                 skb = get_record_skb(sk,
1052                                                      select_size(sk,
1053                                                                  recordsz,
1054                                                                  flags,
1055                                                                  TX_TLSHDR_LEN),
1056                                                                  false);
1057                         } else {
1058                                 skb = get_tx_skb(sk,
1059                                                  select_size(sk, size, flags,
1060                                                              TX_HEADER_LEN));
1061                         }
1062                         if (unlikely(!skb))
1063                                 goto wait_for_memory;
1064
1065                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1066                         copy = mss;
1067                 }
1068                 if (copy > size)
1069                         copy = size;
1070
1071                 if (skb_tailroom(skb) > 0) {
1072                         copy = min(copy, skb_tailroom(skb));
1073                         if (is_tls_tx(csk))
1074                                 copy = min_t(int, copy, csk->tlshws.txleft);
1075                         err = skb_add_data_nocache(sk, skb,
1076                                                    &msg->msg_iter, copy);
1077                         if (err)
1078                                 goto do_fault;
1079                 } else {
1080                         int i = skb_shinfo(skb)->nr_frags;
1081                         struct page *page = TCP_PAGE(sk);
1082                         int pg_size = PAGE_SIZE;
1083                         int off = TCP_OFF(sk);
1084                         bool merge;
1085
1086                         if (!page)
1087                                 goto wait_for_memory;
1088
1089                         pg_size <<= compound_order(page);
1090                         if (off < pg_size &&
1091                             skb_can_coalesce(skb, i, page, off)) {
1092                                 merge = 1;
1093                                 goto copy;
1094                         }
1095                         merge = 0;
1096                         if (i == (is_tls_tx(csk) ? (MAX_SKB_FRAGS - 1) :
1097                             MAX_SKB_FRAGS))
1098                                 goto new_buf;
1099
1100                         if (page && off == pg_size) {
1101                                 put_page(page);
1102                                 TCP_PAGE(sk) = page = NULL;
1103                                 pg_size = PAGE_SIZE;
1104                         }
1105
1106                         if (!page) {
1107                                 gfp_t gfp = sk->sk_allocation;
1108                                 int order = cdev->send_page_order;
1109
1110                                 if (order) {
1111                                         page = alloc_pages(gfp | __GFP_COMP |
1112                                                            __GFP_NOWARN |
1113                                                            __GFP_NORETRY,
1114                                                            order);
1115                                         if (page)
1116                                                 pg_size <<=
1117                                                         compound_order(page);
1118                                 }
1119                                 if (!page) {
1120                                         page = alloc_page(gfp);
1121                                         pg_size = PAGE_SIZE;
1122                                 }
1123                                 if (!page)
1124                                         goto wait_for_memory;
1125                                 off = 0;
1126                         }
1127 copy:
1128                         if (copy > pg_size - off)
1129                                 copy = pg_size - off;
1130                         if (is_tls_tx(csk))
1131                                 copy = min_t(int, copy, csk->tlshws.txleft);
1132
1133                         err = chtls_skb_copy_to_page_nocache(sk, &msg->msg_iter,
1134                                                              skb, page,
1135                                                              off, copy);
1136                         if (unlikely(err)) {
1137                                 if (!TCP_PAGE(sk)) {
1138                                         TCP_PAGE(sk) = page;
1139                                         TCP_OFF(sk) = 0;
1140                                 }
1141                                 goto do_fault;
1142                         }
1143                         /* Update the skb. */
1144                         if (merge) {
1145                                 skb_shinfo(skb)->frags[i - 1].size += copy;
1146                         } else {
1147                                 skb_fill_page_desc(skb, i, page, off, copy);
1148                                 if (off + copy < pg_size) {
1149                                         /* space left keep page */
1150                                         get_page(page);
1151                                         TCP_PAGE(sk) = page;
1152                                 } else {
1153                                         TCP_PAGE(sk) = NULL;
1154                                 }
1155                         }
1156                         TCP_OFF(sk) = off + copy;
1157                 }
1158                 if (unlikely(skb->len == mss))
1159                         tx_skb_finalize(skb);
1160                 tp->write_seq += copy;
1161                 copied += copy;
1162                 size -= copy;
1163
1164                 if (is_tls_tx(csk))
1165                         csk->tlshws.txleft -= copy;
1166
1167                 if (corked(tp, flags) &&
1168                     (sk_stream_wspace(sk) < sk_stream_min_wspace(sk)))
1169                         ULP_SKB_CB(skb)->flags |= ULPCB_FLAG_NO_APPEND;
1170
1171                 if (size == 0)
1172                         goto out;
1173
1174                 if (ULP_SKB_CB(skb)->flags & ULPCB_FLAG_NO_APPEND)
1175                         push_frames_if_head(sk);
1176                 continue;
1177 wait_for_sndbuf:
1178                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1179 wait_for_memory:
1180                 err = csk_wait_memory(cdev, sk, &timeo);
1181                 if (err)
1182                         goto do_error;
1183         }
1184 out:
1185         csk_reset_flag(csk, CSK_TX_MORE_DATA);
1186         if (copied)
1187                 chtls_tcp_push(sk, flags);
1188 done:
1189         release_sock(sk);
1190         return copied + hdrlen;
1191 do_fault:
1192         if (!skb->len) {
1193                 __skb_unlink(skb, &csk->txq);
1194                 sk->sk_wmem_queued -= skb->truesize;
1195                 __kfree_skb(skb);
1196         }
1197 do_error:
1198         if (copied)
1199                 goto out;
1200 out_err:
1201         if (csk_conn_inline(csk))
1202                 csk_reset_flag(csk, CSK_TX_MORE_DATA);
1203         copied = sk_stream_error(sk, flags, err);
1204         goto done;
1205 }
1206
1207 int chtls_sendpage(struct sock *sk, struct page *page,
1208                    int offset, size_t size, int flags)
1209 {
1210         struct chtls_sock *csk;
1211         struct chtls_dev *cdev;
1212         int mss, err, copied;
1213         struct tcp_sock *tp;
1214         long timeo;
1215
1216         tp = tcp_sk(sk);
1217         copied = 0;
1218         csk = rcu_dereference_sk_user_data(sk);
1219         cdev = csk->cdev;
1220         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1221
1222         err = sk_stream_wait_connect(sk, &timeo);
1223         if (!sk_in_state(sk, TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
1224             err != 0)
1225                 goto out_err;
1226
1227         mss = csk->mss;
1228         csk_set_flag(csk, CSK_TX_MORE_DATA);
1229
1230         while (size > 0) {
1231                 struct sk_buff *skb = skb_peek_tail(&csk->txq);
1232                 int copy, i;
1233
1234                 if (!skb || (ULP_SKB_CB(skb)->flags & ULPCB_FLAG_NO_APPEND) ||
1235                     (copy = mss - skb->len) <= 0) {
1236 new_buf:
1237                         if (!csk_mem_free(cdev, sk))
1238                                 goto wait_for_sndbuf;
1239
1240                         if (is_tls_tx(csk)) {
1241                                 skb = get_record_skb(sk,
1242                                                      select_size(sk, size,
1243                                                                  flags,
1244                                                                  TX_TLSHDR_LEN),
1245                                                      true);
1246                         } else {
1247                                 skb = get_tx_skb(sk, 0);
1248                         }
1249                         if (!skb)
1250                                 goto wait_for_memory;
1251                         copy = mss;
1252                 }
1253                 if (copy > size)
1254                         copy = size;
1255
1256                 i = skb_shinfo(skb)->nr_frags;
1257                 if (skb_can_coalesce(skb, i, page, offset)) {
1258                         skb_shinfo(skb)->frags[i - 1].size += copy;
1259                 } else if (i < MAX_SKB_FRAGS) {
1260                         get_page(page);
1261                         skb_fill_page_desc(skb, i, page, offset, copy);
1262                 } else {
1263                         tx_skb_finalize(skb);
1264                         push_frames_if_head(sk);
1265                         goto new_buf;
1266                 }
1267
1268                 skb->len += copy;
1269                 if (skb->len == mss)
1270                         tx_skb_finalize(skb);
1271                 skb->data_len += copy;
1272                 skb->truesize += copy;
1273                 sk->sk_wmem_queued += copy;
1274                 tp->write_seq += copy;
1275                 copied += copy;
1276                 offset += copy;
1277                 size -= copy;
1278
1279                 if (corked(tp, flags) &&
1280                     (sk_stream_wspace(sk) < sk_stream_min_wspace(sk)))
1281                         ULP_SKB_CB(skb)->flags |= ULPCB_FLAG_NO_APPEND;
1282
1283                 if (!size)
1284                         break;
1285
1286                 if (unlikely(ULP_SKB_CB(skb)->flags & ULPCB_FLAG_NO_APPEND))
1287                         push_frames_if_head(sk);
1288                 continue;
1289 wait_for_sndbuf:
1290                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1291 wait_for_memory:
1292                 err = csk_wait_memory(cdev, sk, &timeo);
1293                 if (err)
1294                         goto do_error;
1295         }
1296 out:
1297         csk_reset_flag(csk, CSK_TX_MORE_DATA);
1298         if (copied)
1299                 chtls_tcp_push(sk, flags);
1300 done:
1301         release_sock(sk);
1302         return copied;
1303
1304 do_error:
1305         if (copied)
1306                 goto out;
1307
1308 out_err:
1309         if (csk_conn_inline(csk))
1310                 csk_reset_flag(csk, CSK_TX_MORE_DATA);
1311         copied = sk_stream_error(sk, flags, err);
1312         goto done;
1313 }
1314
1315 static void chtls_select_window(struct sock *sk)
1316 {
1317         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
1318         struct tcp_sock *tp = tcp_sk(sk);
1319         unsigned int wnd = tp->rcv_wnd;
1320
1321         wnd = max_t(unsigned int, wnd, tcp_full_space(sk));
1322         wnd = max_t(unsigned int, MIN_RCV_WND, wnd);
1323
1324         if (wnd > MAX_RCV_WND)
1325                 wnd = MAX_RCV_WND;
1326
1327 /*
1328  * Check if we need to grow the receive window in response to an increase in
1329  * the socket's receive buffer size.  Some applications increase the buffer
1330  * size dynamically and rely on the window to grow accordingly.
1331  */
1332
1333         if (wnd > tp->rcv_wnd) {
1334                 tp->rcv_wup -= wnd - tp->rcv_wnd;
1335                 tp->rcv_wnd = wnd;
1336                 /* Mark the receive window as updated */
1337                 csk_reset_flag(csk, CSK_UPDATE_RCV_WND);
1338         }
1339 }
1340
1341 /*
1342  * Send RX credits through an RX_DATA_ACK CPL message.  We are permitted
1343  * to return without sending the message in case we cannot allocate
1344  * an sk_buff.  Returns the number of credits sent.
1345  */
1346 static u32 send_rx_credits(struct chtls_sock *csk, u32 credits)
1347 {
1348         struct cpl_rx_data_ack *req;
1349         struct sk_buff *skb;
1350
1351         skb = alloc_skb(sizeof(*req), GFP_ATOMIC);
1352         if (!skb)
1353                 return 0;
1354         __skb_put(skb, sizeof(*req));
1355         req = (struct cpl_rx_data_ack *)skb->head;
1356
1357         set_wr_txq(skb, CPL_PRIORITY_ACK, csk->port_id);
1358         INIT_TP_WR(req, csk->tid);
1359         OPCODE_TID(req) = cpu_to_be32(MK_OPCODE_TID(CPL_RX_DATA_ACK,
1360                                                     csk->tid));
1361         req->credit_dack = cpu_to_be32(RX_CREDITS_V(credits) |
1362                                        RX_FORCE_ACK_F);
1363         cxgb4_ofld_send(csk->cdev->ports[csk->port_id], skb);
1364         return credits;
1365 }
1366
1367 #define CREDIT_RETURN_STATE (TCPF_ESTABLISHED | \
1368                              TCPF_FIN_WAIT1 | \
1369                              TCPF_FIN_WAIT2)
1370
1371 /*
1372  * Called after some received data has been read.  It returns RX credits
1373  * to the HW for the amount of data processed.
1374  */
1375 static void chtls_cleanup_rbuf(struct sock *sk, int copied)
1376 {
1377         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
1378         struct tcp_sock *tp;
1379         int must_send;
1380         u32 credits;
1381         u32 thres;
1382
1383         thres = 15 * 1024;
1384
1385         if (!sk_in_state(sk, CREDIT_RETURN_STATE))
1386                 return;
1387
1388         chtls_select_window(sk);
1389         tp = tcp_sk(sk);
1390         credits = tp->copied_seq - tp->rcv_wup;
1391         if (unlikely(!credits))
1392                 return;
1393
1394 /*
1395  * For coalescing to work effectively ensure the receive window has
1396  * at least 16KB left.
1397  */
1398         must_send = credits + 16384 >= tp->rcv_wnd;
1399
1400         if (must_send || credits >= thres)
1401                 tp->rcv_wup += send_rx_credits(csk, credits);
1402 }
1403
1404 static int chtls_pt_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
1405                             int nonblock, int flags, int *addr_len)
1406 {
1407         struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
1408         struct net_device *dev = csk->egress_dev;
1409         struct chtls_hws *hws = &csk->tlshws;
1410         struct tcp_sock *tp = tcp_sk(sk);
1411         struct adapter *adap;
1412         unsigned long avail;
1413         int buffers_freed;
1414         int copied = 0;
1415         int request;
1416         int target;
1417         long timeo;
1418
1419         adap = netdev2adap(dev);
1420         buffers_freed = 0;
1421
1422         timeo = sock_rcvtimeo(sk, nonblock);
1423         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1424         request = len;
1425
1426         if (unlikely(csk_flag(sk, CSK_UPDATE_RCV_WND)))
1427                 chtls_cleanup_rbuf(sk, copied);
1428
1429         do {
1430                 struct sk_buff *skb;
1431                 u32 offset = 0;
1432
1433                 if (unlikely(tp->urg_data &&
1434                              tp->urg_seq == tp->copied_seq)) {
1435                         if (copied)
1436                                 break;
1437                         if (signal_pending(current)) {
1438                                 copied = timeo ? sock_intr_errno(timeo) :
1439                                         -EAGAIN;
1440                                 break;
1441                         }
1442                 }
1443                 skb = skb_peek(&sk->sk_receive_queue);
1444                 if (skb)
1445                         goto found_ok_skb;
1446                 if (csk->wr_credits &&
1447                     skb_queue_len(&csk->txq) &&
1448                     chtls_push_frames(csk, csk->wr_credits ==
1449                                       csk->wr_max_credits))
1450                         sk->sk_write_space(sk);
1451
1452                 if (copied >= target && !sk->sk_backlog.tail)
1453                         break;
1454
1455                 if (copied) {
1456                         if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
1457                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
1458                             signal_pending(current))
1459                                 break;
1460
1461                         if (!timeo)
1462                                 break;
1463                 } else {
1464                         if (sock_flag(sk, SOCK_DONE))
1465                                 break;
1466                         if (sk->sk_err) {
1467                                 copied = sock_error(sk);
1468                                 break;
1469                         }
1470                         if (sk->sk_shutdown & RCV_SHUTDOWN)
1471                                 break;
1472                         if (sk->sk_state == TCP_CLOSE) {
1473                                 copied = -ENOTCONN;
1474                                 break;
1475                         }
1476                         if (!timeo) {
1477                                 copied = -EAGAIN;
1478                                 break;
1479                         }
1480                         if (signal_pending(current)) {
1481                                 copied = sock_intr_errno(timeo);
1482                                 break;
1483                         }
1484                 }
1485                 if (sk->sk_backlog.tail) {
1486                         release_sock(sk);
1487                         lock_sock(sk);
1488                         chtls_cleanup_rbuf(sk, copied);
1489                         continue;
1490                 }
1491
1492                 if (copied >= target)
1493                         break;
1494                 chtls_cleanup_rbuf(sk, copied);
1495                 sk_wait_data(sk, &timeo, NULL);
1496                 continue;
1497 found_ok_skb:
1498                 if (!skb->len) {
1499                         skb_dst_set(skb, NULL);
1500                         __skb_unlink(skb, &sk->sk_receive_queue);
1501                         kfree_skb(skb);
1502
1503                         if (!copied && !timeo) {
1504                                 copied = -EAGAIN;
1505                                 break;
1506                         }
1507
1508                         if (copied < target) {
1509                                 release_sock(sk);
1510                                 lock_sock(sk);
1511                                 continue;
1512                         }
1513                         break;
1514                 }
1515                 offset = hws->copied_seq;
1516                 avail = skb->len - offset;
1517                 if (len < avail)
1518                         avail = len;
1519
1520                 if (unlikely(tp->urg_data)) {
1521                         u32 urg_offset = tp->urg_seq - tp->copied_seq;
1522
1523                         if (urg_offset < avail) {
1524                                 if (urg_offset) {
1525                                         avail = urg_offset;
1526                                 } else if (!sock_flag(sk, SOCK_URGINLINE)) {
1527                                         /* First byte is urgent, skip */
1528                                         tp->copied_seq++;
1529                                         offset++;
1530                                         avail--;
1531                                         if (!avail)
1532                                                 goto skip_copy;
1533                                 }
1534                         }
1535                 }
1536                 if (skb_copy_datagram_msg(skb, offset, msg, avail)) {
1537                         if (!copied) {
1538                                 copied = -EFAULT;
1539                                 break;
1540                         }
1541                 }
1542
1543                 copied += avail;
1544                 len -= avail;
1545                 hws->copied_seq += avail;
1546 skip_copy:
1547                 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq))
1548                         tp->urg_data = 0;
1549
1550                 if ((avail + offset) >= skb->len) {
1551                         if (likely(skb))
1552                                 chtls_free_skb(sk, skb);
1553                         buffers_freed++;
1554                         if (ULP_SKB_CB(skb)->flags & ULPCB_FLAG_TLS_HDR) {
1555                                 tp->copied_seq += skb->len;
1556                                 hws->rcvpld = skb->hdr_len;
1557                         } else {
1558                                 tp->copied_seq += hws->rcvpld;
1559                         }
1560                         hws->copied_seq = 0;
1561                         if (copied >= target &&
1562                             !skb_peek(&sk->sk_receive_queue))
1563                                 break;
1564                 }
1565         } while (len > 0);
1566
1567         if (buffers_freed)
1568                 chtls_cleanup_rbuf(sk, copied);
1569         release_sock(sk);
1570         return copied;
1571 }
1572
1573 /*
1574  * Peek at data in a socket's receive buffer.
1575  */
1576 static int peekmsg(struct sock *sk, struct msghdr *msg,
1577                    size_t len, int nonblock, int flags)
1578 {
1579         struct tcp_sock *tp = tcp_sk(sk);
1580         u32 peek_seq, offset;
1581         struct sk_buff *skb;
1582         int copied = 0;
1583         size_t avail;          /* amount of available data in current skb */
1584         long timeo;
1585
1586         lock_sock(sk);
1587         timeo = sock_rcvtimeo(sk, nonblock);
1588         peek_seq = tp->copied_seq;
1589
1590         do {
1591                 if (unlikely(tp->urg_data && tp->urg_seq == peek_seq)) {
1592                         if (copied)
1593                                 break;
1594                         if (signal_pending(current)) {
1595                                 copied = timeo ? sock_intr_errno(timeo) :
1596                                 -EAGAIN;
1597                                 break;
1598                         }
1599                 }
1600
1601                 skb_queue_walk(&sk->sk_receive_queue, skb) {
1602                         offset = peek_seq - ULP_SKB_CB(skb)->seq;
1603                         if (offset < skb->len)
1604                                 goto found_ok_skb;
1605                 }
1606
1607                 /* empty receive queue */
1608                 if (copied)
1609                         break;
1610                 if (sock_flag(sk, SOCK_DONE))
1611                         break;
1612                 if (sk->sk_err) {
1613                         copied = sock_error(sk);
1614                         break;
1615                 }
1616                 if (sk->sk_shutdown & RCV_SHUTDOWN)
1617                         break;
1618                 if (sk->sk_state == TCP_CLOSE) {
1619                         copied = -ENOTCONN;
1620                         break;
1621                 }
1622                 if (!timeo) {
1623                         copied = -EAGAIN;
1624                         break;
1625                 }
1626                 if (signal_pending(current)) {
1627                         copied = sock_intr_errno(timeo);
1628                         break;
1629                 }
1630
1631                 if (sk->sk_backlog.tail) {
1632                         /* Do not sleep, just process backlog. */
1633                         release_sock(sk);
1634                         lock_sock(sk);
1635                 } else {
1636                         sk_wait_data(sk, &timeo, NULL);
1637                 }
1638
1639                 if (unlikely(peek_seq != tp->copied_seq)) {
1640                         if (net_ratelimit())
1641                                 pr_info("TCP(%s:%d), race in MSG_PEEK.\n",
1642                                         current->comm, current->pid);
1643                         peek_seq = tp->copied_seq;
1644                 }
1645                 continue;
1646
1647 found_ok_skb:
1648                 avail = skb->len - offset;
1649                 if (len < avail)
1650                         avail = len;
1651                 /*
1652                  * Do we have urgent data here?  We need to skip over the
1653                  * urgent byte.
1654                  */
1655                 if (unlikely(tp->urg_data)) {
1656                         u32 urg_offset = tp->urg_seq - peek_seq;
1657
1658                         if (urg_offset < avail) {
1659                                 /*
1660                                  * The amount of data we are preparing to copy
1661                                  * contains urgent data.
1662                                  */
1663                                 if (!urg_offset) { /* First byte is urgent */
1664                                         if (!sock_flag(sk, SOCK_URGINLINE)) {
1665                                                 peek_seq++;
1666                                                 offset++;
1667                                                 avail--;
1668                                         }
1669                                         if (!avail)
1670                                                 continue;
1671                                 } else {
1672                                         /* stop short of the urgent data */
1673                                         avail = urg_offset;
1674                                 }
1675                         }
1676                 }
1677
1678                 /*
1679                  * If MSG_TRUNC is specified the data is discarded.
1680                  */
1681                 if (likely(!(flags & MSG_TRUNC)))
1682                         if (skb_copy_datagram_msg(skb, offset, msg, len)) {
1683                                 if (!copied) {
1684                                         copied = -EFAULT;
1685                                         break;
1686                                 }
1687                         }
1688                 peek_seq += avail;
1689                 copied += avail;
1690                 len -= avail;
1691         } while (len > 0);
1692
1693         release_sock(sk);
1694         return copied;
1695 }
1696
1697 int chtls_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
1698                   int nonblock, int flags, int *addr_len)
1699 {
1700         struct tcp_sock *tp = tcp_sk(sk);
1701         struct chtls_sock *csk;
1702         struct chtls_hws *hws;
1703         unsigned long avail;    /* amount of available data in current skb */
1704         int buffers_freed;
1705         int copied = 0;
1706         int request;
1707         long timeo;
1708         int target;             /* Read at least this many bytes */
1709
1710         buffers_freed = 0;
1711
1712         if (unlikely(flags & MSG_OOB))
1713                 return tcp_prot.recvmsg(sk, msg, len, nonblock, flags,
1714                                         addr_len);
1715
1716         if (unlikely(flags & MSG_PEEK))
1717                 return peekmsg(sk, msg, len, nonblock, flags);
1718
1719         if (sk_can_busy_loop(sk) &&
1720             skb_queue_empty(&sk->sk_receive_queue) &&
1721             sk->sk_state == TCP_ESTABLISHED)
1722                 sk_busy_loop(sk, nonblock);
1723
1724         lock_sock(sk);
1725         csk = rcu_dereference_sk_user_data(sk);
1726         hws = &csk->tlshws;
1727
1728         if (is_tls_rx(csk))
1729                 return chtls_pt_recvmsg(sk, msg, len, nonblock,
1730                                         flags, addr_len);
1731
1732         timeo = sock_rcvtimeo(sk, nonblock);
1733         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1734         request = len;
1735
1736         if (unlikely(csk_flag(sk, CSK_UPDATE_RCV_WND)))
1737                 chtls_cleanup_rbuf(sk, copied);
1738
1739         do {
1740                 struct sk_buff *skb;
1741                 u32 offset;
1742
1743                 if (unlikely(tp->urg_data && tp->urg_seq == tp->copied_seq)) {
1744                         if (copied)
1745                                 break;
1746                         if (signal_pending(current)) {
1747                                 copied = timeo ? sock_intr_errno(timeo) :
1748                                         -EAGAIN;
1749                                 break;
1750                         }
1751                 }
1752
1753                 skb = skb_peek(&sk->sk_receive_queue);
1754                 if (skb)
1755                         goto found_ok_skb;
1756
1757                 if (csk->wr_credits &&
1758                     skb_queue_len(&csk->txq) &&
1759                     chtls_push_frames(csk, csk->wr_credits ==
1760                                       csk->wr_max_credits))
1761                         sk->sk_write_space(sk);
1762
1763                 if (copied >= target && !sk->sk_backlog.tail)
1764                         break;
1765
1766                 if (copied) {
1767                         if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
1768                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
1769                             signal_pending(current))
1770                                 break;
1771                 } else {
1772                         if (sock_flag(sk, SOCK_DONE))
1773                                 break;
1774                         if (sk->sk_err) {
1775                                 copied = sock_error(sk);
1776                                 break;
1777                         }
1778                         if (sk->sk_shutdown & RCV_SHUTDOWN)
1779                                 break;
1780                         if (sk->sk_state == TCP_CLOSE) {
1781                                 copied = -ENOTCONN;
1782                                 break;
1783                         }
1784                         if (!timeo) {
1785                                 copied = -EAGAIN;
1786                                 break;
1787                         }
1788                         if (signal_pending(current)) {
1789                                 copied = sock_intr_errno(timeo);
1790                                 break;
1791                         }
1792                 }
1793
1794                 if (sk->sk_backlog.tail) {
1795                         release_sock(sk);
1796                         lock_sock(sk);
1797                         chtls_cleanup_rbuf(sk, copied);
1798                         continue;
1799                 }
1800
1801                 if (copied >= target)
1802                         break;
1803                 chtls_cleanup_rbuf(sk, copied);
1804                 sk_wait_data(sk, &timeo, NULL);
1805                 continue;
1806
1807 found_ok_skb:
1808                 if (!skb->len) {
1809                         chtls_kfree_skb(sk, skb);
1810                         if (!copied && !timeo) {
1811                                 copied = -EAGAIN;
1812                                 break;
1813                         }
1814
1815                         if (copied < target)
1816                                 continue;
1817
1818                         break;
1819                 }
1820
1821                 offset = tp->copied_seq - ULP_SKB_CB(skb)->seq;
1822                 avail = skb->len - offset;
1823                 if (len < avail)
1824                         avail = len;
1825
1826                 if (unlikely(tp->urg_data)) {
1827                         u32 urg_offset = tp->urg_seq - tp->copied_seq;
1828
1829                         if (urg_offset < avail) {
1830                                 if (urg_offset) {
1831                                         avail = urg_offset;
1832                                 } else if (!sock_flag(sk, SOCK_URGINLINE)) {
1833                                         tp->copied_seq++;
1834                                         offset++;
1835                                         avail--;
1836                                         if (!avail)
1837                                                 goto skip_copy;
1838                                 }
1839                         }
1840                 }
1841
1842                 if (likely(!(flags & MSG_TRUNC))) {
1843                         if (skb_copy_datagram_msg(skb, offset,
1844                                                   msg, avail)) {
1845                                 if (!copied) {
1846                                         copied = -EFAULT;
1847                                         break;
1848                                 }
1849                         }
1850                 }
1851
1852                 tp->copied_seq += avail;
1853                 copied += avail;
1854                 len -= avail;
1855
1856 skip_copy:
1857                 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq))
1858                         tp->urg_data = 0;
1859
1860                 if (avail + offset >= skb->len) {
1861                         if (likely(skb))
1862                                 chtls_free_skb(sk, skb);
1863                         buffers_freed++;
1864
1865                         if  (copied >= target &&
1866                              !skb_peek(&sk->sk_receive_queue))
1867                                 break;
1868                 }
1869         } while (len > 0);
1870
1871         if (buffers_freed)
1872                 chtls_cleanup_rbuf(sk, copied);
1873
1874         release_sock(sk);
1875         return copied;
1876 }