source4/libcli/resolve/resolve.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    general name resolution interface
   5
   6    Copyright (C) Andrew Tridgell 2005
   7    Copyright (C) Jelmer Vernooij 2007
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "lib/events/events.h"
  25 #include "libcli/composite/composite.h"
  26 #include "libcli/resolve/resolve.h"
  27 #include "librpc/gen_ndr/ndr_nbt.h"
  28 #include "param/param.h"
  29 #include "system/network.h"
  30 #include "util/dlinklist.h"
  31
  32 struct resolve_state {
  33         struct resolve_context *ctx;
  34         struct resolve_method *method;
  35         struct nbt_name name;
  36         struct composite_context *creq;
  37         const char *reply_addr;
  38 };
  39
  40 static struct composite_context *setup_next_method(struct composite_context *c);
  41
  42
  43 struct resolve_context {
  44         struct resolve_method {
  45                 resolve_name_send_fn send_fn;
  46                 resolve_name_recv_fn recv_fn;
  47                 void *privdata;
  48                 struct resolve_method *prev, *next;
  49         } *methods;
  50 };
  51
  52 /**
  53  * Initialize a resolve context
  54  */
  55 struct resolve_context *resolve_context_init(TALLOC_CTX *mem_ctx)
  56 {
  57         return talloc_zero(mem_ctx, struct resolve_context);
  58 }
  59
  60 /**
  61  * Add a resolve method
  62  */
  63 bool resolve_context_add_method(struct resolve_context *ctx, resolve_name_send_fn send_fn,
  64                                 resolve_name_recv_fn recv_fn, void *userdata)
  65 {
  66         struct resolve_method *method = talloc_zero(ctx, struct resolve_method);
  67
  68         if (method == NULL)
  69                 return false;
  70
  71         method->send_fn = send_fn;
  72         method->recv_fn = recv_fn;
  73         method->privdata = userdata;
  74         DLIST_ADD_END(ctx->methods, method, struct resolve_method *);
  75         return true;
  76 }
  77
  78 /**
  79   handle completion of one name resolve method
  80 */
  81 static void resolve_handler(struct composite_context *creq)
  82 {
  83         struct composite_context *c = (struct composite_context *)creq->async.private_data;
  84         struct resolve_state *state = talloc_get_type(c->private_data, struct resolve_state);
  85         const struct resolve_method *method = state->method;
  86
  87         c->status = method->recv_fn(creq, state, &state->reply_addr);
  88
  89         if (!NT_STATUS_IS_OK(c->status)) {
  90                 state->method = state->method->next;
  91                 state->creq = setup_next_method(c);
  92                 if (state->creq != NULL) {
  93                         return;
  94                 }
  95         }
  96
  97         if (!NT_STATUS_IS_OK(c->status)) {
  98                 c->state = COMPOSITE_STATE_ERROR;
  99         } else {
 100                 c->state = COMPOSITE_STATE_DONE;
 101         }
 102         if (c->async.fn) {
 103                 c->async.fn(c);
 104         }
 105 }
 106
 107
 108 static struct composite_context *setup_next_method(struct composite_context *c)
 109 {
 110         struct resolve_state *state = talloc_get_type(c->private_data, struct resolve_state);
 111         struct composite_context *creq = NULL;
 112
 113         do {
 114                 if (state->method) {
 115                         creq = state->method->send_fn(c, c->event_ctx, state->method->privdata, &state->name);
 116                 }
 117                 if (creq == NULL && state->method) state->method = state->method->next;
 118
 119         } while (!creq && state->method);
 120
 121         if (creq) {
 122                 creq->async.fn = resolve_handler;
 123                 creq->async.private_data = c;
 124         }
 125
 126         return creq;
 127 }
 128
 129 /*
 130   general name resolution - async send
 131  */
 132 struct composite_context *resolve_name_send(struct resolve_context *ctx,
 133                                             struct nbt_name *name,
 134                                             struct event_context *event_ctx)
 135 {
 136         struct composite_context *c;
 137         struct resolve_state *state;
 138
 139         if (ctx == NULL || event_ctx == NULL) {
 140                 return NULL;
 141         }
 142
 143         c = composite_create(ctx, event_ctx);
 144         if (c == NULL) return NULL;
 145
 146         if (composite_nomem(c->event_ctx, c)) return c;
 147
 148         state = talloc(c, struct resolve_state);
 149         if (composite_nomem(state, c)) return c;
 150         c->private_data = state;
 151
 152         c->status = nbt_name_dup(state, name, &state->name);
 153         if (!composite_is_ok(c)) return c;
 154
 155         state->ctx = talloc_reference(state, ctx);
 156         if (composite_nomem(state->ctx, c)) return c;
 157
 158         if (is_ipaddress(state->name.name) ||
 159             strcasecmp(state->name.name, "localhost") == 0) {
 160                 struct in_addr ip = interpret_addr2(state->name.name);
 161                 state->reply_addr = talloc_strdup(state, inet_ntoa(ip));
 162                 if (composite_nomem(state->reply_addr, c)) return c;
 163                 composite_done(c);
 164                 return c;
 165         }
 166
 167         state->method = ctx->methods;
 168         state->creq = setup_next_method(c);
 169         if (composite_nomem(state->creq, c)) return c;
 170
 171         return c;
 172 }
 173
 174 /*
 175   general name resolution method - recv side
 176  */
 177 NTSTATUS resolve_name_recv(struct composite_context *c,
 178                            TALLOC_CTX *mem_ctx, const char **reply_addr)
 179 {
 180         NTSTATUS status;
 181
 182         status = composite_wait(c);
 183
 184         if (NT_STATUS_IS_OK(status)) {
 185                 struct resolve_state *state = talloc_get_type(c->private_data, struct resolve_state);
 186                 *reply_addr = talloc_steal(mem_ctx, state->reply_addr);
 187         }
 188
 189         talloc_free(c);
 190         return status;
 191 }
 192
 193 /*
 194   general name resolution - sync call
 195  */
 196 NTSTATUS resolve_name(struct resolve_context *ctx, struct nbt_name *name, TALLOC_CTX *mem_ctx, const char **reply_addr, struct event_context *ev)
 197 {
 198         struct composite_context *c = resolve_name_send(ctx, name, ev);
 199         return resolve_name_recv(c, mem_ctx, reply_addr);
 200 }
 201
 202 /* Initialise a struct nbt_name with a NULL scope */
 203
 204 void make_nbt_name(struct nbt_name *nbt, const char *name, int type)
 205 {
 206         nbt->name = name;
 207         nbt->scope = NULL;
 208         nbt->type = type;
 209 }
 210
 211 /* Initialise a struct nbt_name with a NBT_NAME_CLIENT (0x00) name */
 212
 213 void make_nbt_name_client(struct nbt_name *nbt, const char *name)
 214 {
 215         make_nbt_name(nbt, name, NBT_NAME_CLIENT);
 216 }
 217
 218 /* Initialise a struct nbt_name with a NBT_NAME_SERVER (0x20) name */
 219
 220 void make_nbt_name_server(struct nbt_name *nbt, const char *name)
 221 {
 222         make_nbt_name(nbt, name, NBT_NAME_SERVER);
 223 }
 224
 225