X-Git-Url: http://git.samba.org/samba.git/?p=obnox%2Fwireshark%2Fwip.git;a=blobdiff_plain;f=packet-udp.c;h=d7c30ab3247a659f39d29500ed5966ce15b9120c;hp=1797409ea582e81a15b709e4019ca8332c533d57;hb=44e31c9f7d49177878959eb16049bb8ffeb1b5b2;hpb=b9def412b0e908e6ac2a3c374548cf01f9064371 diff --git a/packet-udp.c b/packet-udp.c index 1797409ea5..d7c30ab324 100644 --- a/packet-udp.c +++ b/packet-udp.c @@ -1,10 +1,10 @@ /* packet-udp.c * Routines for UDP packet disassembly * - * $Id: packet-udp.c,v 1.20 1999/07/08 04:23:04 gram Exp $ + * $Id: packet-udp.c,v 1.100 2001/12/10 00:25:40 guy Exp $ * * Ethereal - Network traffic analyzer - * By Gerald Combs + * By Gerald Combs * Copyright 1998 Gerald Combs * * Richard Sharpe, 13-Feb-1999, added dispatch table support and @@ -39,12 +39,32 @@ #include #include +#include #include #include "packet.h" #include "resolv.h" +#include "ipproto.h" +#include "in_cksum.h" +#include "prefs.h" -extern packet_info pi; +#include "packet-udp.h" + +#include "packet-ip.h" +#include "conversation.h" + +static int proto_udp = -1; +static int hf_udp_srcport = -1; +static int hf_udp_dstport = -1; +static int hf_udp_port = -1; +static int hf_udp_length = -1; +static int hf_udp_checksum = -1; +static int hf_udp_checksum_bad = -1; + +static gint ett_udp = -1; + +/* Place UDP summary in proto tree */ +static gboolean udp_summary_in_tree = TRUE; /* UDP structs and definitions */ @@ -55,215 +75,216 @@ typedef struct _e_udphdr { guint16 uh_sum; } e_udphdr; -/* UDP Ports -> should go in packet-udp.h */ - -#define UDP_PORT_DNS 53 -#define UDP_PORT_BOOTPS 67 -#define UDP_PORT_TFTP 69 -#define UDP_PORT_IPX 213 -#define UDP_PORT_NBNS 137 -#define UDP_PORT_NBDGM 138 -#define UDP_PORT_SNMP 161 -#define UDP_PORT_ISAKMP 500 -#define UDP_PORT_RIP 520 -#define UDP_PORT_VINES 573 -#define UDP_PORT_RADIUS 1645 -#define UDP_PORT_RADIUS_NEW 1812 -#define UDP_PORT_RADACCT 1646 -#define UDP_PORT_RADACCT_NEW 1813 - - -struct hash_struct { - guint16 proto; - void (*dissect)(const u_char *, int, frame_data *, proto_tree *); - struct hash_struct *next; -}; - -struct hash_struct *hash_table[256]; - -/* - * These routines are for UDP, will be generalized soon: RJS - * - * XXX - note that they should probably check the IP address as well as - * the port number, so that we don't mistakenly identify packets as, say, - * TFTP, merely because they have a source or destination port number - * equal to the port being used by a TFTP daemon on some machine other - * than the one they're going to or from. - */ - -struct hash_struct *udp_find_hash_ent(guint16 proto) { - - int idx = proto % 256; - struct hash_struct *hash_ent = hash_table[idx]; - - while (hash_ent != NULL) { - - if (hash_ent -> proto == proto) - return hash_ent; - - hash_ent = hash_ent -> next; - - } - - return NULL; - -} +static dissector_table_t udp_dissector_table; +static heur_dissector_list_t heur_subdissector_list; +static dissector_handle_t data_handle; -void udp_hash_add(guint16 proto, - void (*dissect)(const u_char *, int, frame_data *, proto_tree *)) { +/* Determine if there is a sub-dissector and call it. This has been */ +/* separated into a stand alone routine to other protocol dissectors */ +/* can call to it, ie. socks */ - int idx = proto % 256; /* Simply take the remainder, hope for no collisions */ - struct hash_struct *hash_ent = (struct hash_struct *)malloc(sizeof(struct hash_struct)); - struct hash_struct *hash_ent2; - - hash_ent -> proto = proto; - hash_ent -> dissect = dissect; - hash_ent -> next = NULL; - - if (hash_ent == NULL) { - - fprintf(stderr, "Could not allocate space for hash structure in dissect_udp\n"); - exit(1); - } - - if (hash_table[idx]) { /* Something, add on end */ - - hash_ent2 = hash_table[idx]; +void +decode_udp_ports(tvbuff_t *tvb, int offset, packet_info *pinfo, + proto_tree *tree, int uh_sport, int uh_dport) +{ + tvbuff_t *next_tvb; - while (hash_ent2 -> next != NULL) - hash_ent2 = hash_ent2 -> next; + next_tvb = tvb_new_subset(tvb, offset, -1, -1); - hash_ent2 -> next = hash_ent; /* Bad in pathalogical cases */ +/* determine if this packet is part of a conversation and call dissector */ +/* for the conversation if available */ - } - else { + if (try_conversation_dissector(&pinfo->src, &pinfo->dst, PT_UDP, + uh_sport, uh_dport, next_tvb, pinfo, tree)) + return; - hash_table[idx] = hash_ent; + /* do lookup with the subdissector table */ + if (dissector_try_port(udp_dissector_table, uh_sport, next_tvb, pinfo, tree) || + dissector_try_port(udp_dissector_table, uh_dport, next_tvb, pinfo, tree)) + return; - } + /* do lookup with the heuristic subdissector table */ + if (dissector_try_heuristic(heur_subdissector_list, next_tvb, pinfo, tree)) + return; + call_dissector(data_handle,next_tvb, pinfo, tree); } -void init_dissect_udp(void) { - - int i; - for (i = 0; i < 256; i++) { - - hash_table[i] = NULL; - - } - - /* Now add the protocols we know about */ - - udp_hash_add(UDP_PORT_BOOTPS, dissect_bootp); - udp_hash_add(UDP_PORT_TFTP, dissect_tftp); - -} - -void -dissect_udp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) { +static void +dissect_udp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) +{ e_udphdr uh; guint16 uh_sport, uh_dport, uh_ulen, uh_sum; - struct hash_struct *dissect_routine = NULL; proto_tree *udp_tree; proto_item *ti; - guint payload; + guint len; + guint reported_len; + vec_t cksum_vec[4]; + guint32 phdr[2]; + guint16 computed_cksum; + int offset = 0; + + if (check_col(pinfo->cinfo, COL_PROTOCOL)) + col_set_str(pinfo->cinfo, COL_PROTOCOL, "UDP"); + if (check_col(pinfo->cinfo, COL_INFO)) + col_clear(pinfo->cinfo, COL_INFO); - /* To do: Check for {cap len,pkt len} < struct len */ /* Avoids alignment problems on many architectures. */ - memcpy(&uh, &pd[offset], sizeof(e_udphdr)); + tvb_memcpy(tvb, (guint8 *)&uh, offset, sizeof(e_udphdr)); uh_sport = ntohs(uh.uh_sport); uh_dport = ntohs(uh.uh_dport); uh_ulen = ntohs(uh.uh_ulen); uh_sum = ntohs(uh.uh_sum); - payload = pi.payload - sizeof(e_udphdr); - - if (check_col(fd, COL_PROTOCOL)) - col_add_str(fd, COL_PROTOCOL, "UDP"); - if (check_col(fd, COL_INFO)) - col_add_fstr(fd, COL_INFO, "Source port: %s Destination port: %s", + if (check_col(pinfo->cinfo, COL_INFO)) + col_add_fstr(pinfo->cinfo, COL_INFO, "Source port: %s Destination port: %s", get_udp_port(uh_sport), get_udp_port(uh_dport)); - if (check_col(fd, COL_RES_SRC_PORT)) - col_add_str(fd, COL_RES_SRC_PORT, get_udp_port(uh_sport)); - if (check_col(fd, COL_UNRES_SRC_PORT)) - col_add_fstr(fd, COL_UNRES_SRC_PORT, "%u", uh_sport); - if (check_col(fd, COL_RES_DST_PORT)) - col_add_str(fd, COL_RES_DST_PORT, get_udp_port(uh_dport)); - if (check_col(fd, COL_UNRES_DST_PORT)) - col_add_fstr(fd, COL_UNRES_DST_PORT, "%u", uh_dport); if (tree) { - ti = proto_tree_add_text(tree, offset, 8, "User Datagram Protocol"); - udp_tree = proto_item_add_subtree(ti, ETT_UDP); - proto_tree_add_text(udp_tree, offset, 2, "Source port: %s (%u)", - get_udp_port(uh_sport), uh_sport); - proto_tree_add_text(udp_tree, offset + 2, 2, "Destination port: %s (%u)", - get_udp_port(uh_dport), uh_dport); - proto_tree_add_text(udp_tree, offset + 4, 2, "Length: %u", uh_ulen); - proto_tree_add_text(udp_tree, offset + 6, 2, "Checksum: 0x%04x", uh_sum); + if (udp_summary_in_tree) { + ti = proto_tree_add_protocol_format(tree, proto_udp, tvb, offset, 8, + "User Datagram Protocol, Src Port: %s (%u), Dst Port: %s (%u)", + get_udp_port(uh_sport), uh_sport, get_udp_port(uh_dport), uh_dport); + } else { + ti = proto_tree_add_item(tree, proto_udp, tvb, offset, 8, FALSE); + } + udp_tree = proto_item_add_subtree(ti, ett_udp); + + proto_tree_add_uint_format(udp_tree, hf_udp_srcport, tvb, offset, 2, uh_sport, + "Source port: %s (%u)", get_udp_port(uh_sport), uh_sport); + proto_tree_add_uint_format(udp_tree, hf_udp_dstport, tvb, offset + 2, 2, uh_dport, + "Destination port: %s (%u)", get_udp_port(uh_dport), uh_dport); + + proto_tree_add_uint_hidden(udp_tree, hf_udp_port, tvb, offset, 2, uh_sport); + proto_tree_add_uint_hidden(udp_tree, hf_udp_port, tvb, offset+2, 2, uh_dport); + + proto_tree_add_uint(udp_tree, hf_udp_length, tvb, offset + 4, 2, uh_ulen); + reported_len = tvb_reported_length(tvb); + len = tvb_length(tvb); + if (uh_sum == 0) { + /* No checksum supplied in the packet. */ + proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb, + offset + 6, 2, uh_sum, "Checksum: 0x%04x (none)", uh_sum); + } else if (!pinfo->fragmented && len >= reported_len && len >= uh_ulen) { + /* The packet isn't part of a fragmented datagram and isn't + truncated, so we can checksum it. + XXX - make a bigger scatter-gather list once we do fragment + reassembly? */ + + /* Set up the fields of the pseudo-header. */ + cksum_vec[0].ptr = pinfo->src.data; + cksum_vec[0].len = pinfo->src.len; + cksum_vec[1].ptr = pinfo->dst.data; + cksum_vec[1].len = pinfo->dst.len; + cksum_vec[2].ptr = (const guint8 *)&phdr; + switch (pinfo->src.type) { + + case AT_IPv4: + phdr[0] = htonl((IP_PROTO_UDP<<16) + reported_len); + cksum_vec[2].len = 4; + break; + + case AT_IPv6: + phdr[0] = htonl(reported_len); + phdr[1] = htonl(IP_PROTO_UDP); + cksum_vec[2].len = 8; + break; + + default: + /* TCP runs only atop IPv4 and IPv6.... */ + g_assert_not_reached(); + break; + } + cksum_vec[3].ptr = tvb_get_ptr(tvb, offset, len); + cksum_vec[3].len = reported_len; + computed_cksum = in_cksum(&cksum_vec[0], 4); + if (computed_cksum == 0) { + proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb, + offset + 6, 2, uh_sum, "Checksum: 0x%04x (correct)", uh_sum); + } else { + proto_tree_add_boolean_hidden(udp_tree, hf_udp_checksum_bad, tvb, + offset + 6, 2, TRUE); + proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb, + offset + 6, 2, uh_sum, + "Checksum: 0x%04x (incorrect, should be 0x%04x)", uh_sum, + in_cksum_shouldbe(uh_sum, computed_cksum)); + } + } else { + proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb, + offset + 6, 2, uh_sum, "Checksum: 0x%04x", uh_sum); + } } /* Skip over header */ offset += 8; - /* XXX - we should do all of this through the table of ports. */ -#define PORT_IS(port) (uh_sport == port || uh_dport == port) - if (PORT_IS(UDP_PORT_BOOTPS)) - dissect_bootp(pd, offset, fd, tree); - else if (PORT_IS(UDP_PORT_DNS)) - dissect_dns(pd, offset, fd, tree); - else if (PORT_IS(UDP_PORT_ISAKMP)) - dissect_isakmp(pd, offset, fd, tree); - else if (PORT_IS(UDP_PORT_RIP)) { - /* we should check the source port too (RIP: UDP src and dst port 520) */ - dissect_rip(pd, offset, fd, tree); - } else if (PORT_IS(UDP_PORT_NBNS)) - dissect_nbns(pd, offset, fd, tree); - else if (PORT_IS(UDP_PORT_NBDGM)) - dissect_nbdgm(pd, offset, fd, tree, payload); - else if (PORT_IS(UDP_PORT_IPX)) /* RFC 1234 */ - dissect_ipx(pd, offset, fd, tree); -#if defined(HAVE_UCD_SNMP_SNMP_H) || defined(HAVE_SNMP_SNMP_H) - else if (PORT_IS(UDP_PORT_SNMP)) - dissect_snmp(pd, offset, fd, tree); -#endif - else if (PORT_IS(UDP_PORT_VINES)) { - /* FIXME: AFAIK, src and dst port must be the same */ - dissect_vines_frp(pd, offset, fd, tree); - } else if (PORT_IS(UDP_PORT_TFTP)) { - /* This is the first point of call, but it adds a dynamic call */ - udp_hash_add(MAX(uh_sport, uh_dport), dissect_tftp); /* Add to table */ - dissect_tftp(pd, offset, fd, tree); - } else if (PORT_IS(UDP_PORT_RADIUS) || - PORT_IS(UDP_PORT_RADACCT) || - PORT_IS(UDP_PORT_RADIUS_NEW) || - PORT_IS(UDP_PORT_RADACCT_NEW) ) { - dissect_radius(pd, offset, fd, tree); - } else { - /* OK, find a routine in the table, else use the default */ + pinfo->ptype = PT_UDP; + pinfo->srcport = uh_sport; + pinfo->destport = uh_dport; - if ((dissect_routine = udp_find_hash_ent(uh_sport))) { +/* call sub-dissectors */ + decode_udp_ports( tvb, offset, pinfo, tree, uh_sport, uh_dport); - struct hash_struct *dr2 = udp_find_hash_ent(uh_dport); - - if (dr2 == NULL) { /* Not in the table, add */ - - udp_hash_add(uh_dport, dissect_tftp); - - } - - dissect_routine -> dissect(pd, offset, fd, tree); - } - else if ((dissect_routine = udp_find_hash_ent(uh_dport))) { +} - dissect_routine -> dissect(pd, offset, fd, tree); +void +proto_register_udp(void) +{ + module_t *udp_module; + static hf_register_info hf[] = { + { &hf_udp_srcport, + { "Source Port", "udp.srcport", FT_UINT16, BASE_DEC, NULL, 0x0, + "", HFILL }}, + + { &hf_udp_dstport, + { "Destination Port", "udp.dstport", FT_UINT16, BASE_DEC, NULL, 0x0, + "", HFILL }}, + + { &hf_udp_port, + { "Source or Destination Port", "udp.port", FT_UINT16, BASE_DEC, NULL, 0x0, + "", HFILL }}, + + { &hf_udp_length, + { "Length", "udp.length", FT_UINT16, BASE_DEC, NULL, 0x0, + "", HFILL }}, + + { &hf_udp_checksum_bad, + { "Bad Checksum", "udp.checksum_bad", FT_BOOLEAN, BASE_NONE, NULL, 0x0, + "", HFILL }}, + + { &hf_udp_checksum, + { "Checksum", "udp.checksum", FT_UINT16, BASE_HEX, NULL, 0x0, + "", HFILL }}, + }; + static gint *ett[] = { + &ett_udp, + }; + + proto_udp = proto_register_protocol("User Datagram Protocol", + "UDP", "udp"); + proto_register_field_array(proto_udp, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + +/* subdissector code */ + udp_dissector_table = register_dissector_table("udp.port", + "UDP port", FT_UINT16, BASE_DEC); + register_heur_dissector_list("udp", &heur_subdissector_list); + + /* Register configuration preferences */ + udp_module = prefs_register_protocol(proto_udp, NULL); + prefs_register_bool_preference(udp_module, "udp_summary_in_tree", + "Show UDP summary in protocol treee", + "Whether the UDP summary line should be shown in the protocol tree", + &udp_summary_in_tree); +} - } - else { +void +proto_reg_handoff_udp(void) +{ + dissector_handle_t udp_handle; - dissect_data(pd, offset, fd, tree); - } - } + udp_handle = create_dissector_handle(dissect_udp, proto_udp); + dissector_add("ip.proto", IP_PROTO_UDP, udp_handle); + data_handle = find_dissector("data"); }