source/libcli/resolve/resolve.c

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