socket-util.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <assert.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <errno.h>
  26 #include <stdlib.h>
  27 #include <arpa/inet.h>
  28 #include <stdio.h>
  29 #include <net/if.h>
  30
  31 #include "macro.h"
  32 #include "util.h"
  33 #include "socket-util.h"
  34
  35 int socket_address_parse(SocketAddress *a, const char *s) {
  36         int r;
  37         char *e, *n;
  38         unsigned u;
  39
  40         assert(a);
  41         assert(s);
  42
  43         zero(*a);
  44         a->type = SOCK_STREAM;
  45
  46         if (*s == '[') {
  47                 /* IPv6 in [x:.....:z]:p notation */
  48
  49                 if (!(e = strchr(s+1, ']')))
  50                         return -EINVAL;
  51
  52                 if (!(n = strndup(s+1, e-s-1)))
  53                         return -ENOMEM;
  54
  55                 errno = 0;
  56                 if (inet_pton(AF_INET6, n, &a->sockaddr.in6.sin6_addr) <= 0) {
  57                         free(n);
  58                         return errno != 0 ? -errno : -EINVAL;
  59                 }
  60
  61                 free(n);
  62
  63                 e++;
  64                 if (*e != ':')
  65                         return -EINVAL;
  66
  67                 e++;
  68                 if ((r = safe_atou(e, &u)) < 0)
  69                         return r;
  70
  71                 if (u <= 0 || u > 0xFFFF)
  72                         return -EINVAL;
  73
  74                 a->sockaddr.in6.sin6_family = AF_INET6;
  75                 a->sockaddr.in6.sin6_port = htons((uint16_t) u);
  76                 a->size = sizeof(struct sockaddr_in6);
  77
  78         } else if (*s == '/') {
  79                 /* AF_UNIX socket */
  80
  81                 size_t l;
  82
  83                 l = strlen(s);
  84                 if (l >= sizeof(a->sockaddr.un.sun_path))
  85                         return -EINVAL;
  86
  87                 a->sockaddr.un.sun_family = AF_UNIX;
  88                 memcpy(a->sockaddr.un.sun_path, s, l);
  89                 a->size = sizeof(sa_family_t) + l + 1;
  90
  91         } else if (*s == '@') {
  92                 /* Abstract AF_UNIX socket */
  93                 size_t l;
  94
  95                 l = strlen(s+1);
  96                 if (l >= sizeof(a->sockaddr.un.sun_path) - 1)
  97                         return -EINVAL;
  98
  99                 a->sockaddr.un.sun_family = AF_UNIX;
 100                 memcpy(a->sockaddr.un.sun_path+1, s+1, l);
 101                 a->size = sizeof(struct sockaddr_un);
 102
 103         } else {
 104
 105                 if ((e = strchr(s, ':'))) {
 106                         int r;
 107
 108                         if ((r = safe_atou(e+1, &u)) < 0)
 109                                 return r;
 110
 111                         if (u <= 0 || u > 0xFFFF)
 112                                 return -EINVAL;
 113
 114                         if (!(n = strndup(s, e-s)))
 115                                 return -ENOMEM;
 116
 117                         /* IPv4 in w.x.y.z:p notation? */
 118                         if ((r = inet_pton(AF_INET, n, &a->sockaddr.in4.sin_addr)) < 0) {
 119                                 free(n);
 120                                 return -errno;
 121                         }
 122
 123                         if (r > 0) {
 124                                 /* Gotcha, it's a traditional IPv4 address */
 125                                 free(n);
 126
 127                                 a->sockaddr.in4.sin_family = AF_INET;
 128                                 a->sockaddr.in4.sin_port = htons((uint16_t) u);
 129                                 a->size = sizeof(struct sockaddr_in);
 130                         } else {
 131                                 unsigned idx;
 132
 133                                 if (strlen(n) > IF_NAMESIZE-1) {
 134                                         free(n);
 135                                         return -EINVAL;
 136                                 }
 137
 138                                 /* Uh, our last resort, an interface name */
 139                                 idx = if_nametoindex(n);
 140                                 free(n);
 141
 142                                 if (idx == 0)
 143                                         return -EINVAL;
 144
 145                                 a->sockaddr.in6.sin6_family = AF_INET6;
 146                                 a->sockaddr.in6.sin6_port = htons((uint16_t) u);
 147                                 a->sockaddr.in6.sin6_scope_id = idx;
 148                                 a->sockaddr.in6.sin6_addr = in6addr_any;
 149                                 a->size = sizeof(struct sockaddr_in6);
 150
 151                         }
 152                 } else {
 153
 154                         /* Just a port */
 155                         if ((r = safe_atou(s, &u)) < 0)
 156                                 return r;
 157
 158                         if (u <= 0 || u > 0xFFFF)
 159                                 return -EINVAL;
 160
 161                         a->sockaddr.in6.sin6_family = AF_INET6;
 162                         a->sockaddr.in6.sin6_port = htons((uint16_t) u);
 163                         a->sockaddr.in6.sin6_addr = in6addr_any;
 164                         a->size = sizeof(struct sockaddr_in6);
 165                 }
 166         }
 167
 168         return 0;
 169 }
 170
 171 int socket_address_verify(const SocketAddress *a) {
 172         assert(a);
 173
 174         switch (socket_address_family(a)) {
 175                 case AF_INET:
 176                         if (a->size != sizeof(struct sockaddr_in))
 177                                 return -EINVAL;
 178
 179                         if (a->sockaddr.in4.sin_port == 0)
 180                                 return -EINVAL;
 181
 182                         return 0;
 183
 184                 case AF_INET6:
 185                         if (a->size != sizeof(struct sockaddr_in6))
 186                                 return -EINVAL;
 187
 188                         if (a->sockaddr.in6.sin6_port == 0)
 189                                 return -EINVAL;
 190
 191                         return 0;
 192
 193                 case AF_UNIX:
 194                         if (a->size < sizeof(sa_family_t))
 195                                 return -EINVAL;
 196
 197                         if (a->size > sizeof(sa_family_t)) {
 198
 199                                 if (a->sockaddr.un.sun_path[0] == 0) {
 200                                         /* abstract */
 201                                         if (a->size != sizeof(struct sockaddr_un))
 202                                                 return -EINVAL;
 203                                 } else {
 204                                         char *e;
 205
 206                                         /* path */
 207                                         if (!(e = memchr(a->sockaddr.un.sun_path, 0, sizeof(a->sockaddr.un.sun_path))))
 208                                                 return -EINVAL;
 209
 210                                         if (a->size != sizeof(sa_family_t) + (e - a->sockaddr.un.sun_path) + 1)
 211                                                 return -EINVAL;
 212                                 }
 213                         }
 214
 215                         return 0;
 216
 217                 default:
 218                         return -EAFNOSUPPORT;
 219         }
 220 }
 221
 222 int socket_address_print(const SocketAddress *a, char **p) {
 223         int r;
 224         assert(a);
 225         assert(p);
 226
 227         if ((r = socket_address_verify(a)) < 0)
 228                 return r;
 229
 230         switch (socket_address_family(a)) {
 231                 case AF_INET: {
 232                         char *ret;
 233
 234                         if (!(ret = new(char, INET_ADDRSTRLEN+1+5+1)))
 235                                 return -ENOMEM;
 236
 237                         if (!inet_ntop(AF_INET, &a->sockaddr.in4.sin_addr, ret, INET_ADDRSTRLEN)) {
 238                                 free(ret);
 239                                 return -errno;
 240                         }
 241
 242                         sprintf(strchr(ret, 0), ":%u", ntohs(a->sockaddr.in4.sin_port));
 243                         *p = ret;
 244                         return 0;
 245                 }
 246
 247                 case AF_INET6: {
 248                         char *ret;
 249
 250                         if (!(ret = new(char, 1+INET6_ADDRSTRLEN+2+5+1)))
 251                                 return -ENOMEM;
 252
 253                         ret[0] = '[';
 254                         if (!inet_ntop(AF_INET6, &a->sockaddr.in6.sin6_addr, ret+1, INET6_ADDRSTRLEN)) {
 255                                 free(ret);
 256                                 return -errno;
 257                         }
 258
 259                         sprintf(strchr(ret, 0), "]:%u", ntohs(a->sockaddr.in6.sin6_port));
 260                         *p = ret;
 261                         return 0;
 262                 }
 263
 264                 case AF_UNIX: {
 265                         char *ret;
 266
 267                         if (a->size <= sizeof(sa_family_t)) {
 268
 269                                 if (!(ret = strdup("<unamed>")))
 270                                         return -ENOMEM;
 271
 272                         } else if (a->sockaddr.un.sun_path[0] == 0) {
 273                                 /* abstract */
 274
 275                                 /* FIXME: We assume we can print the
 276                                  * socket path here and that it hasn't
 277                                  * more than one NUL byte. That is
 278                                  * actually an invalid assumption */
 279
 280                                 if (!(ret = new(char, sizeof(a->sockaddr.un.sun_path)+1)))
 281                                         return -ENOMEM;
 282
 283                                 ret[0] = '@';
 284                                 memcpy(ret+1, a->sockaddr.un.sun_path+1, sizeof(a->sockaddr.un.sun_path)-1);
 285                                 ret[sizeof(a->sockaddr.un.sun_path)] = 0;
 286
 287                         } else {
 288
 289                                 if (!(ret = strdup(a->sockaddr.un.sun_path)))
 290                                         return -ENOMEM;
 291                         }
 292
 293                         *p = ret;
 294                         return 0;
 295                 }
 296
 297                 default:
 298                         return -EINVAL;
 299         }
 300 }
 301
 302 int socket_address_listen(const SocketAddress *a, int backlog, SocketAddressBindIPv6Only only, const char *bind_to_device, int *ret) {
 303         int r, fd, one;
 304         assert(a);
 305         assert(ret);
 306
 307         if ((r = socket_address_verify(a)) < 0)
 308                 return r;
 309
 310         if ((fd = socket(socket_address_family(a), a->type | SOCK_NONBLOCK | SOCK_CLOEXEC, 0)) < 0)
 311                 return -errno;
 312
 313         if (socket_address_family(a) == AF_INET6 && only != SOCKET_ADDRESS_DEFAULT) {
 314                 int flag = only == SOCKET_ADDRESS_IPV6_ONLY;
 315
 316                 if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &flag, sizeof(flag)) < 0)
 317                         goto fail;
 318         }
 319
 320         if (bind_to_device)
 321                 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, bind_to_device, strlen(bind_to_device)+1) < 0)
 322                         goto fail;
 323
 324         one = 1;
 325         if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
 326                 goto fail;
 327
 328         if (bind(fd, &a->sockaddr.sa, a->size) < 0)
 329                 goto fail;
 330
 331         if (a->type == SOCK_STREAM)
 332                 if (listen(fd, backlog) < 0)
 333                         goto fail;
 334
 335         *ret = fd;
 336         return 0;
 337
 338 fail:
 339         r = -errno;
 340         close_nointr(fd);
 341         return r;
 342 }