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