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
 107                         if ((r = safe_atou(e+1, &u)) < 0)
 108                                 return r;
 109
 110                         if (u <= 0 || u > 0xFFFF)
 111                                 return -EINVAL;
 112
 113                         if (!(n = strndup(s, e-s)))
 114                                 return -ENOMEM;
 115
 116                         /* IPv4 in w.x.y.z:p notation? */
 117                         if ((r = inet_pton(AF_INET, n, &a->sockaddr.in4.sin_addr)) < 0) {
 118                                 free(n);
 119                                 return -errno;
 120                         }
 121
 122                         if (r > 0) {
 123                                 /* Gotcha, it's a traditional IPv4 address */
 124                                 free(n);
 125
 126                                 a->sockaddr.in4.sin_family = AF_INET;
 127                                 a->sockaddr.in4.sin_port = htons((uint16_t) u);
 128                                 a->size = sizeof(struct sockaddr_in);
 129                         } else {
 130                                 unsigned idx;
 131
 132                                 if (strlen(n) > IF_NAMESIZE-1) {
 133                                         free(n);
 134                                         return -EINVAL;
 135                                 }
 136
 137                                 /* Uh, our last resort, an interface name */
 138                                 idx = if_nametoindex(n);
 139                                 free(n);
 140
 141                                 if (idx == 0)
 142                                         return -EINVAL;
 143
 144                                 a->sockaddr.in6.sin6_family = AF_INET6;
 145                                 a->sockaddr.in6.sin6_port = htons((uint16_t) u);
 146                                 a->sockaddr.in6.sin6_scope_id = idx;
 147                                 a->sockaddr.in6.sin6_addr = in6addr_any;
 148                                 a->size = sizeof(struct sockaddr_in6);
 149
 150                         }
 151                 } else {
 152
 153                         /* Just a port */
 154                         if ((r = safe_atou(s, &u)) < 0)
 155                                 return r;
 156
 157                         if (u <= 0 || u > 0xFFFF)
 158                                 return -EINVAL;
 159
 160                         a->sockaddr.in6.sin6_family = AF_INET6;
 161                         a->sockaddr.in6.sin6_port = htons((uint16_t) u);
 162                         a->sockaddr.in6.sin6_addr = in6addr_any;
 163                         a->size = sizeof(struct sockaddr_in6);
 164                 }
 165         }
 166
 167         return 0;
 168 }
 169
 170 int socket_address_verify(const SocketAddress *a) {
 171         assert(a);
 172
 173         switch (socket_address_family(a)) {
 174                 case AF_INET:
 175                         if (a->size != sizeof(struct sockaddr_in))
 176                                 return -EINVAL;
 177
 178                         if (a->sockaddr.in4.sin_port == 0)
 179                                 return -EINVAL;
 180
 181                         return 0;
 182
 183                 case AF_INET6:
 184                         if (a->size != sizeof(struct sockaddr_in6))
 185                                 return -EINVAL;
 186
 187                         if (a->sockaddr.in6.sin6_port == 0)
 188                                 return -EINVAL;
 189
 190                         return 0;
 191
 192                 case AF_UNIX:
 193                         if (a->size < sizeof(sa_family_t))
 194                                 return -EINVAL;
 195
 196                         if (a->size > sizeof(sa_family_t)) {
 197
 198                                 if (a->sockaddr.un.sun_path[0] == 0) {
 199                                         /* abstract */
 200                                         if (a->size != sizeof(struct sockaddr_un))
 201                                                 return -EINVAL;
 202                                 } else {
 203                                         char *e;
 204
 205                                         /* path */
 206                                         if (!(e = memchr(a->sockaddr.un.sun_path, 0, sizeof(a->sockaddr.un.sun_path))))
 207                                                 return -EINVAL;
 208
 209                                         if (a->size != sizeof(sa_family_t) + (e - a->sockaddr.un.sun_path) + 1)
 210                                                 return -EINVAL;
 211                                 }
 212                         }
 213
 214                         return 0;
 215
 216                 default:
 217                         return -EAFNOSUPPORT;
 218         }
 219 }
 220
 221 int socket_address_print(const SocketAddress *a, char **p) {
 222         int r;
 223         assert(a);
 224         assert(p);
 225
 226         if ((r = socket_address_verify(a)) < 0)
 227                 return r;
 228
 229         switch (socket_address_family(a)) {
 230                 case AF_INET: {
 231                         char *ret;
 232
 233                         if (!(ret = new(char, INET_ADDRSTRLEN+1+5+1)))
 234                                 return -ENOMEM;
 235
 236                         if (!inet_ntop(AF_INET, &a->sockaddr.in4.sin_addr, ret, INET_ADDRSTRLEN)) {
 237                                 free(ret);
 238                                 return -errno;
 239                         }
 240
 241                         sprintf(strchr(ret, 0), ":%u", ntohs(a->sockaddr.in4.sin_port));
 242                         *p = ret;
 243                         return 0;
 244                 }
 245
 246                 case AF_INET6: {
 247                         char *ret;
 248
 249                         if (!(ret = new(char, 1+INET6_ADDRSTRLEN+2+5+1)))
 250                                 return -ENOMEM;
 251
 252                         ret[0] = '[';
 253                         if (!inet_ntop(AF_INET6, &a->sockaddr.in6.sin6_addr, ret+1, INET6_ADDRSTRLEN)) {
 254                                 free(ret);
 255                                 return -errno;
 256                         }
 257
 258                         sprintf(strchr(ret, 0), "]:%u", ntohs(a->sockaddr.in6.sin6_port));
 259                         *p = ret;
 260                         return 0;
 261                 }
 262
 263                 case AF_UNIX: {
 264                         char *ret;
 265
 266                         if (a->size <= sizeof(sa_family_t)) {
 267
 268                                 if (!(ret = strdup("<unamed>")))
 269                                         return -ENOMEM;
 270
 271                         } else if (a->sockaddr.un.sun_path[0] == 0) {
 272                                 /* abstract */
 273
 274                                 /* FIXME: We assume we can print the
 275                                  * socket path here and that it hasn't
 276                                  * more than one NUL byte. That is
 277                                  * actually an invalid assumption */
 278
 279                                 if (!(ret = new(char, sizeof(a->sockaddr.un.sun_path)+1)))
 280                                         return -ENOMEM;
 281
 282                                 ret[0] = '@';
 283                                 memcpy(ret+1, a->sockaddr.un.sun_path+1, sizeof(a->sockaddr.un.sun_path)-1);
 284                                 ret[sizeof(a->sockaddr.un.sun_path)] = 0;
 285
 286                         } else {
 287
 288                                 if (!(ret = strdup(a->sockaddr.un.sun_path)))
 289                                         return -ENOMEM;
 290                         }
 291
 292                         *p = ret;
 293                         return 0;
 294                 }
 295
 296                 default:
 297                         return -EINVAL;
 298         }
 299 }
 300
 301 int socket_address_listen(const SocketAddress *a, int backlog, SocketAddressBindIPv6Only only, const char *bind_to_device, int *ret) {
 302         int r, fd, one;
 303         assert(a);
 304         assert(ret);
 305
 306         if ((r = socket_address_verify(a)) < 0)
 307                 return r;
 308
 309         if ((fd = socket(socket_address_family(a), a->type | SOCK_NONBLOCK | SOCK_CLOEXEC, 0)) < 0)
 310                 return -errno;
 311
 312         if (socket_address_family(a) == AF_INET6 && only != SOCKET_ADDRESS_DEFAULT) {
 313                 int flag = only == SOCKET_ADDRESS_IPV6_ONLY;
 314
 315                 if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &flag, sizeof(flag)) < 0)
 316                         goto fail;
 317         }
 318
 319         if (bind_to_device)
 320                 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, bind_to_device, strlen(bind_to_device)+1) < 0)
 321                         goto fail;
 322
 323         one = 1;
 324         if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
 325                 goto fail;
 326
 327         if (bind(fd, &a->sockaddr.sa, a->size) < 0)
 328                 goto fail;
 329
 330         if (a->type == SOCK_STREAM)
 331                 if (listen(fd, backlog) < 0)
 332                         goto fail;
 333
 334         *ret = fd;
 335         return 0;
 336
 337 fail:
 338         r = -errno;
 339         close_nointr(fd);
 340         return r;
 341 }