socket-util.c

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