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
   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
  29 struct resolve_state {
  30         struct nbt_name name;
  31         const char **methods;
  32         struct composite_context *creq;
  33         const char *reply_addr;
  34 };
  35
  36 static struct composite_context *setup_next_method(struct composite_context *c);
  37
  38 /* pointers to the resolver backends */
  39 static const struct resolve_method {
  40         const char *name;
  41         struct composite_context *(*send_fn)(TALLOC_CTX *mem_ctx, struct event_context *, struct nbt_name *);
  42         NTSTATUS (*recv_fn)(struct composite_context *, TALLOC_CTX *, const char **);
  43
  44 } resolve_methods[] = {
  45         { "bcast", resolve_name_bcast_send,  resolve_name_bcast_recv },
  46         { "wins",  resolve_name_wins_send,   resolve_name_wins_recv },
  47         { "host",  resolve_name_host_send,   resolve_name_host_recv }
  48 };
  49
  50
  51 /*
  52    find a matching backend
  53 */
  54 static const struct resolve_method *find_method(const char *name)
  55 {
  56         int i;
  57         if (name == NULL) return NULL;
  58         for (i=0;i<ARRAY_SIZE(resolve_methods);i++) {
  59                 if (strcasecmp(name, resolve_methods[i].name) == 0) {
  60                         return &resolve_methods[i];
  61                 }
  62         }
  63         return NULL;
  64 }
  65
  66 /*
  67   handle completion of one name resolve method
  68 */
  69 static void resolve_handler(struct composite_context *creq)
  70 {
  71         struct composite_context *c = (struct composite_context *)creq->async.private_data;
  72         struct resolve_state *state = talloc_get_type(c->private_data, struct resolve_state);
  73         const struct resolve_method *method = find_method(state->methods[0]);
  74
  75         c->status = method->recv_fn(creq, state, &state->reply_addr);
  76
  77         if (!NT_STATUS_IS_OK(c->status)) {
  78                 state->methods++;
  79                 state->creq = setup_next_method(c);
  80                 if (state->creq != NULL) {
  81                         return;
  82                 }
  83         }
  84
  85         if (!NT_STATUS_IS_OK(c->status)) {
  86                 c->state = COMPOSITE_STATE_ERROR;
  87         } else {
  88                 c->state = COMPOSITE_STATE_DONE;
  89         }
  90         if (c->async.fn) {
  91                 c->async.fn(c);
  92         }
  93 }
  94
  95
  96 static struct composite_context *setup_next_method(struct composite_context *c)
  97 {
  98         struct resolve_state *state = talloc_get_type(c->private_data, struct resolve_state);
  99         struct composite_context *creq = NULL;
 100
 101         do {
 102                 const struct resolve_method *method = find_method(state->methods[0]);
 103                 if (method) {
 104                         creq = method->send_fn(c, c->event_ctx, &state->name);
 105                 }
 106                 if (creq == NULL && state->methods[0]) state->methods++;
 107
 108         } while (!creq && state->methods[0]);
 109
 110         if (creq) {
 111                 creq->async.fn = resolve_handler;
 112                 creq->async.private_data = c;
 113         }
 114
 115         return creq;
 116 }
 117
 118 /*
 119   general name resolution - async send
 120  */
 121 struct composite_context *resolve_name_send(struct nbt_name *name, struct event_context *event_ctx,
 122                                             const char **methods)
 123 {
 124         struct composite_context *c;
 125         struct resolve_state *state;
 126
 127         c = composite_create(event_ctx, event_ctx);
 128         if (c == NULL) return NULL;
 129
 130         if (methods == NULL) {
 131                 composite_error(c, NT_STATUS_INVALID_PARAMETER);
 132                 return c;
 133         }
 134
 135         if (event_ctx == NULL) {
 136                 c->event_ctx = event_context_init(c);
 137         } else {
 138                 c->event_ctx = talloc_reference(c, event_ctx);
 139         }
 140         if (composite_nomem(c->event_ctx, c)) return c;
 141
 142         state = talloc(c, struct resolve_state);
 143         if (composite_nomem(state, c)) return c;
 144         c->private_data = state;
 145
 146         c->status = nbt_name_dup(state, name, &state->name);
 147         if (!composite_is_ok(c)) return c;
 148
 149         state->methods = str_list_copy(state, methods);
 150         if (composite_nomem(state->methods, c)) return c;
 151
 152         if (is_ipaddress(state->name.name) ||
 153             strcasecmp(state->name.name, "localhost") == 0) {
 154                 struct ipv4_addr ip = interpret_addr2(state->name.name);
 155                 state->reply_addr = talloc_strdup(state, sys_inet_ntoa(ip));
 156                 if (composite_nomem(state->reply_addr, c)) return c;
 157                 composite_done(c);
 158                 return c;
 159         }
 160
 161         state->creq = setup_next_method(c);
 162         if (composite_nomem(state->creq, c)) return c;
 163
 164         return c;
 165 }
 166
 167 /*
 168   general name resolution method - recv side
 169  */
 170 NTSTATUS resolve_name_recv(struct composite_context *c,
 171                            TALLOC_CTX *mem_ctx, const char **reply_addr)
 172 {
 173         NTSTATUS status;
 174
 175         status = composite_wait(c);
 176
 177         if (NT_STATUS_IS_OK(status)) {
 178                 struct resolve_state *state = talloc_get_type(c->private_data, struct resolve_state);
 179                 *reply_addr = talloc_steal(mem_ctx, state->reply_addr);
 180         }
 181
 182         talloc_free(c);
 183         return status;
 184 }
 185
 186 /*
 187   general name resolution - sync call
 188  */
 189 NTSTATUS resolve_name(struct nbt_name *name, TALLOC_CTX *mem_ctx, const char **reply_addr,
 190                       struct event_context *ev)
 191 {
 192         struct composite_context *c = resolve_name_send(name, ev,
 193                                                 lp_name_resolve_order(global_loadparm));
 194         return resolve_name_recv(c, mem_ctx, reply_addr);
 195 }
 196
 197 /* Initialise a struct nbt_name with a NULL scope */
 198
 199 void make_nbt_name(struct nbt_name *nbt, const char *name, int type)
 200 {
 201         nbt->name = name;
 202         nbt->scope = NULL;
 203         nbt->type = type;
 204 }
 205
 206 /* Initialise a struct nbt_name with a NBT_NAME_CLIENT (0x00) name */
 207
 208 void make_nbt_name_client(struct nbt_name *nbt, const char *name)
 209 {
 210         make_nbt_name(nbt, name, NBT_NAME_CLIENT);
 211 }
 212
 213 /* Initialise a struct nbt_name with a NBT_NAME_SERVER (0x20) name */
 214
 215 void make_nbt_name_server(struct nbt_name *nbt, const char *name)
 216 {
 217         make_nbt_name(nbt, name, NBT_NAME_SERVER);
 218 }