mdw@git.distorted.org.uk Git - disorder/blob - lib/addr.c

   1 /*
   2  * This file is part of DisOrder.
   3  * Copyright (C) 2004, 2007, 2008, 2013 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/addr.c
  19  * @brief Socket address support */
  20
  21 #include "common.h"
  22
  23 #include <stddef.h>
  24
  25 #include <sys/types.h>
  26 #if HAVE_SYS_SOCKET_H
  27 # include <sys/socket.h>
  28 #endif
  29 #if HAVE_NETINET_IN_H
  30 # include <netinet/in.h>
  31 #endif
  32 #if HAVE_ARPA_INET_H
  33 # include <arpa/inet.h>
  34 #endif
  35 #if HAVE_SYS_UN_H
  36 # include <sys/un.h>
  37 #endif
  38 #if HAVE_WS2TCPIP_H
  39 # include <Ws2tcpip.h>
  40 #endif
  41
  42 #include "log.h"
  43 #include "printf.h"
  44 #include "addr.h"
  45 #include "mem.h"
  46 #include "syscalls.h"
  47 #include "configuration.h"
  48 #include "vector.h"
  49
  50 /** @brief Convert a pair of strings to an address
  51  * @param a Pointer to string list
  52  * @param pref Hints structure for getaddrinfo, or NULL
  53  * @param namep Where to store address description, or NULL
  54  * @return Address info structure or NULL on error
  55  *
  56  * This converts one or two strings into an address specification suitable
  57  * for passing to socket(), bind() etc.
  58  *
  59  * If there is only one string then it is assumed to be the service
  60  * name (port number).  If there are two then the first is the host
  61  * name and the second the service name.
  62  *
  63  * @p namep is used to return a description of the address suitable
  64  * for use in log messages.
  65  *
  66  * If an error occurs a message is logged and a null pointer returned.
  67  */
  68 struct addrinfo *get_address(const struct stringlist *a,
  69                              const struct addrinfo *pref,
  70                              char **namep) {
  71   struct addrinfo *res;
  72   char *name;
  73   int rc;
  74   char errbuf[1024];
  75
  76   switch(a->n) {
  77   case 1:
  78     byte_xasprintf(&name, "host * service %s", a->s[0]);
  79     if((rc = getaddrinfo(0, a->s[0], pref, &res))) {
  80       disorder_error(0, "getaddrinfo %s: %s", a->s[0],
  81                      format_error(ec_getaddrinfo, rc, errbuf, sizeof errbuf));
  82       return 0;
  83     }
  84     break;
  85   case 2:
  86     byte_xasprintf(&name, "host %s service %s", a->s[0], a->s[1]);
  87     if((rc = getaddrinfo(a->s[0], a->s[1], pref, &res))) {
  88       disorder_error(0, "getaddrinfo %s %s: %s",
  89                      a->s[0], a->s[1],
  90                      format_error(ec_getaddrinfo, rc, errbuf, sizeof errbuf));
  91       return 0;
  92     }
  93     break;
  94   default:
  95     disorder_error(0, "invalid network address specification (n=%d)", a->n);
  96     return 0;
  97   }
  98   if(!res || (pref && res->ai_socktype != pref->ai_socktype)) {
  99     disorder_error(0, "getaddrinfo didn't give us a suitable socket address");
 100     if(res)
 101       freeaddrinfo(res);
 102     return 0;
 103   }
 104   if(namep)
 105     *namep = name;
 106   return res;
 107 }
 108
 109 /** @brief Comparison function for address information
 110  *
 111  * Suitable for qsort().
 112  */
 113 int addrinfocmp(const struct addrinfo *a,
 114                 const struct addrinfo *b) {
 115   if(a->ai_family != b->ai_family) return a->ai_family - b->ai_family;
 116   if(a->ai_socktype != b->ai_socktype) return a->ai_socktype - b->ai_socktype;
 117   if(a->ai_protocol != b->ai_protocol) return a->ai_protocol - b->ai_protocol;
 118   return sockaddrcmp(a->ai_addr, b->ai_addr);
 119 }
 120
 121 /** @brief Comparison function for socket addresses
 122  *
 123  * Suitable for qsort().
 124  */
 125 int sockaddrcmp(const struct sockaddr *a,
 126                 const struct sockaddr *b) {
 127   const struct sockaddr_in *ina, *inb;
 128   const struct sockaddr_in6 *in6a, *in6b;
 129
 130   if(a->sa_family != b->sa_family) return a->sa_family - b->sa_family;
 131   switch(a->sa_family) {
 132   case PF_INET:
 133     ina = (const struct sockaddr_in *)a;
 134     inb = (const struct sockaddr_in *)b;
 135     if(ina->sin_port != inb->sin_port) return ina->sin_port - inb->sin_port;
 136     return ina->sin_addr.s_addr - inb->sin_addr.s_addr;
 137     break;
 138   case PF_INET6:
 139     in6a = (const struct sockaddr_in6 *)a;
 140     in6b = (const struct sockaddr_in6 *)b;
 141     if(in6a->sin6_port != in6b->sin6_port)
 142       return in6a->sin6_port - in6b->sin6_port;
 143     return memcmp(&in6a->sin6_addr, &in6b->sin6_addr,
 144                   sizeof (struct in6_addr));
 145   default:
 146     disorder_fatal(0, "unsupported protocol family %d", a->sa_family);
 147   }
 148 }
 149
 150 /** @brief Return nonzero if @p sin4 is an IPv4 multicast address */
 151 static inline int multicast4(const struct sockaddr_in *sin4) {
 152   return IN_MULTICAST(ntohl(sin4->sin_addr.s_addr));
 153 }
 154
 155 /** @brief Return nonzero if @p sin6 is an IPv6 multicast address */
 156 static inline int multicast6(const struct sockaddr_in6 *sin6) {
 157   return IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr);
 158 }
 159
 160 /** @brief Return true if @p sa represents a multicast address */
 161 int multicast(const struct sockaddr *sa) {
 162   switch(sa->sa_family) {
 163   case AF_INET:
 164     return multicast4((const struct sockaddr_in *)sa);
 165   case AF_INET6:
 166     return multicast6((const struct sockaddr_in6 *)sa);
 167   default:
 168     return 0;
 169   }
 170 }
 171
 172 /** @brief Format an IPv4 address */
 173 static inline char *format_sockaddr4(const struct sockaddr_in *sin4) {
 174   char buffer[1024], *r;
 175
 176   if(sin4->sin_port)
 177     byte_xasprintf(&r, "%s port %u",
 178                    inet_ntop(sin4->sin_family, (void *)&sin4->sin_addr,
 179                              buffer, sizeof buffer),
 180                    ntohs(sin4->sin_port));
 181   else
 182     byte_xasprintf(&r, "%s",
 183                    inet_ntop(sin4->sin_family, (void *)&sin4->sin_addr,
 184                              buffer, sizeof buffer));
 185   return r;
 186 }
 187
 188 /** @brief Format an IPv6 address */
 189 static inline char *format_sockaddr6(const struct sockaddr_in6 *sin6) {
 190   char buffer[1024], *r;
 191
 192   if(sin6->sin6_port)
 193     byte_xasprintf(&r, "%s port %u",
 194                    inet_ntop(sin6->sin6_family, (void *)&sin6->sin6_addr,
 195                              buffer, sizeof buffer),
 196                    ntohs(sin6->sin6_port));
 197   else
 198     byte_xasprintf(&r, "%s",
 199                    inet_ntop(sin6->sin6_family, (void *)&sin6->sin6_addr,
 200                              buffer, sizeof buffer));
 201   return r;
 202 }
 203
 204 #if HAVE_SYS_UN_H
 205 /** @brief Format a UNIX socket address */
 206 static inline char *format_sockaddrun(const struct sockaddr_un *sun) {
 207   return xstrdup(sun->sun_path);
 208 }
 209 #endif
 210
 211 /** @brief Construct a text description a sockaddr
 212  * @param sa Socket address
 213  * @return Human-readable form of address
 214  */
 215 char *format_sockaddr(const struct sockaddr *sa) {
 216   switch(sa->sa_family) {
 217   case AF_INET:
 218     return format_sockaddr4((const struct sockaddr_in *)sa);
 219   case AF_INET6:
 220     return format_sockaddr6((const struct sockaddr_in6 *)sa);
 221 #if HAVE_SYS_UN_H
 222   case AF_UNIX:
 223     return format_sockaddrun((const struct sockaddr_un *)sa);
 224 #endif
 225   default:
 226     return 0;
 227   }
 228 }
 229
 230 /** @brief Parse the text form of a network address
 231  * @param na Where to store result
 232  * @param nvec Number of strings
 233  * @param vec List of strings
 234  * @return 0 on success, -1 on syntax error
 235  */
 236 int netaddress_parse(struct netaddress *na,
 237                      int nvec,
 238                      char **vec) {
 239   const char *port;
 240   long p;
 241   int e;
 242
 243   na->af = AF_UNSPEC;
 244   if(nvec > 0 && vec[0][0] == '-') {
 245     if(!strcmp(vec[0], "-4"))
 246       na->af = AF_INET;
 247     else if(!strcmp(vec[0], "-6"))
 248       na->af = AF_INET6;
 249     else if(!strcmp(vec[0], "-unix"))
 250       na->af = AF_UNIX;
 251     else if(!strcmp(vec[0], "-"))
 252       na->af = AF_UNSPEC;
 253     else
 254       return -1;
 255     --nvec;
 256     ++vec;
 257   }
 258   if(nvec == 0)
 259     return -1;
 260   /* Possibilities are:
 261    *
 262    *       /path/to/unix/socket      an AF_UNIX socket
 263    *       * PORT                    any address, specific port
 264    *       PORT                      any address, specific port
 265    *       ADDRESS PORT              specific address, specific port
 266    */
 267   if(vec[0][0] == '/' && na->af == AF_UNSPEC)
 268     na->af = AF_UNIX;
 269   if(na->af == AF_UNIX) {
 270     if(nvec != 1)
 271       return -1;
 272     na->address = xstrdup(vec[0]);
 273     na->port = -1;                      /* makes no sense */
 274   } else {
 275     switch(nvec) {
 276     case 1:
 277       na->address = NULL;
 278       port = vec[0];
 279       break;
 280     case 2:
 281       if(!strcmp(vec[0], "*"))
 282         na->address = NULL;
 283       else
 284         na->address = xstrdup(vec[0]);
 285       port = vec[1];
 286       break;
 287     default:
 288       return -1;
 289     }
 290     if(port[strspn(port, "0123456789")])
 291       return -1;
 292     e = xstrtol(&p, port, NULL, 10);
 293
 294     if(e)
 295       return -1;
 296     if(p > 65535)
 297       return -1;
 298     na->port = (int)p;
 299   }
 300   return 0;
 301 }
 302
 303 /** @brief Format a @ref netaddress structure
 304  * @param na Network address to format
 305  * @param nvecp Where to put string count, or NULL
 306  * @param vecp Where to put strings
 307  *
 308  * The formatted form is suitable for passing to netaddress_parse().
 309  */
 310 void netaddress_format(const struct netaddress *na,
 311                        int *nvecp,
 312                        char ***vecp) {
 313   struct vector v[1];
 314
 315   vector_init(v);
 316   switch(na->af) {
 317   case AF_UNSPEC: vector_append(v, xstrdup("-")); break;
 318   case AF_INET: vector_append(v, xstrdup("-4")); break;
 319   case AF_INET6: vector_append(v, xstrdup("-6")); break;
 320   case AF_UNIX: vector_append(v, xstrdup("-unix")); break;
 321   }
 322   if(na->address)
 323     vector_append(v, xstrdup(na->address));
 324   else
 325     vector_append(v, xstrdup("*"));
 326   if(na->port != -1) {
 327     char buffer[64];
 328
 329     byte_snprintf(buffer, sizeof buffer, "%d", na->port);
 330     vector_append(v, xstrdup(buffer));
 331   }
 332   vector_terminate(v);
 333   if(nvecp)
 334     *nvecp = v->nvec;
 335   if(vecp)
 336     *vecp = v->vec;
 337 }
 338
 339 /** @brief Resolve a network address
 340  * @param na Address structure
 341  * @param passive True if passive (bindable) address is desired
 342  * @param protocol Protocol number desired (e.g. @c IPPROTO_TCP)
 343  * @return List of suitable addresses or NULL
 344  *
 345  * Free the address using netaddress_freeaddrinfo() because it might not
 346  * have come from getaddrinfo() directly.
 347  */
 348 struct addrinfo *netaddress_resolve(const struct netaddress *na,
 349                                     int passive,
 350                                     int protocol) {
 351   struct addrinfo *res, hints[1];
 352   struct sockaddr_un *sun;
 353   char service[64];
 354   int rc;
 355   char errbuf[1024];
 356
 357 #if HAVE_SYS_UN_H
 358   if (na->af == AF_UNIX) {
 359     /* `getaddrinfo' won't work, so we make our own one */
 360     res = xmalloc(sizeof(*res));
 361     res->ai_flags = 0;
 362     res->ai_family = AF_UNIX;
 363     res->ai_socktype = (protocol == IPPROTO_UDP ? SOCK_DGRAM : SOCK_STREAM);
 364     res->ai_protocol = 0;
 365     res->ai_addrlen = offsetof(struct sockaddr_un, sun_path) +
 366       strlen(na->address) + 1;
 367     sun = xmalloc(res->ai_addrlen);
 368     sun->sun_family = AF_UNIX;
 369     strcpy(sun->sun_path, na->address);
 370     res->ai_addr = (struct sockaddr *)sun;
 371     res->ai_canonname = sun->sun_path;
 372     res->ai_next = 0;
 373   } else
 374 #endif
 375   {
 376     /* get the system to do the heavy lifting */
 377     memset(hints, 0, sizeof hints);
 378     hints->ai_family = na->af;
 379     hints->ai_protocol = protocol;
 380     hints->ai_flags = passive ? AI_PASSIVE : 0;
 381     byte_snprintf(service, sizeof service, "%d", na->port);
 382     rc = getaddrinfo(na->address, service, hints, &res);
 383     if(rc) {
 384       disorder_error(0, "getaddrinfo %s %d: %s",
 385                      na->address ? na->address : "*",
 386                      na->port,
 387                      format_error(ec_getaddrinfo, rc, errbuf, sizeof errbuf));
 388       return NULL;
 389     }
 390     assert(res->ai_family != AF_UNIX);
 391   }
 392   return res;
 393 }
 394
 395 /** @brief Free an address-info list from netaddress_resovle()
 396  * @param res Address-info list
 397  */
 398 void netaddress_freeaddrinfo(struct addrinfo *res) {
 399 #if HAVE_SYS_UN_H
 400   if(res->ai_family == AF_UNIX) {
 401     xfree(res->ai_addr);
 402     xfree(res);
 403   } else
 404 #endif
 405     freeaddrinfo(res);
 406 }
 407
 408 /*
 409 Local Variables:
 410 c-basic-offset:2
 411 comment-column:40
 412 End:
 413 */