diff options
Diffstat (limited to 'libesmtp/getaddrinfo.c')
| -rw-r--r-- | libesmtp/getaddrinfo.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/libesmtp/getaddrinfo.c b/libesmtp/getaddrinfo.c new file mode 100644 index 00000000..575b51d2 --- /dev/null +++ b/libesmtp/getaddrinfo.c @@ -0,0 +1,314 @@ +/* + * This file is part of libESMTP, a library for submission of RFC 2822 + * formatted electronic mail messages using the SMTP protocol described + * in RFC 2821. + * + * Copyright (C) 2001,2002 Brian Stafford <brian@stafford.uklinux.net> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/* An emulation of the RFC 2553 / Posix getaddrinfo resolver interface. + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +/* Need to turn off Posix features in glibc to build this */ +#undef _POSIX_C_SOURCE +#undef _XOPEN_SOURCE + +#include <stdlib.h> +#include <string.h> +#include <ctype.h> +#include <errno.h> + +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> + +#include <netdb.h> + +#include "gethostbyname.h" +#include "getaddrinfo.h" + +static struct addrinfo * +dup_addrinfo (struct addrinfo *info, void *addr, size_t addrlen) +{ + struct addrinfo *ret; + + ret = malloc (sizeof (struct addrinfo)); + if (ret == NULL) + return NULL; + memcpy (ret, info, sizeof (struct addrinfo)); + ret->ai_addr = malloc (addrlen); + if (ret->ai_addr == NULL) + { + free (ret); + return NULL; + } + memcpy (ret->ai_addr, addr, addrlen); + ret->ai_addrlen = addrlen; + return ret; +} + +int +getaddrinfo (const char *nodename, const char *servname, + const struct addrinfo *hints, struct addrinfo **res) +{ + struct hostent *hp; + struct servent *servent; + const char *socktype; + int port; + struct addrinfo hint, result; + struct addrinfo *ai, *sai, *eai; + struct ghbnctx ghbnctx; + char **addrs; + int code; + + memset (&result, 0, sizeof result); + + /* default for hints */ + if (hints == NULL) + { + memset (&hint, 0, sizeof hint); + hint.ai_family = PF_UNSPEC; + hints = &hint; + } + + /* servname must not be NULL in this implementation */ + if (servname == NULL) + return EAI_NONAME; + + /* check for tcp or udp sockets only */ + if (hints->ai_socktype == SOCK_STREAM) + socktype = "tcp"; + else if (hints->ai_socktype == SOCK_DGRAM) + socktype = "udp"; + else + return EAI_SERVICE; + result.ai_socktype = hints->ai_socktype; + + /* Note: maintain port in host byte order to make debugging easier */ + if (isdigit (*servname)) + port = strtol (servname, NULL, 10); + else if ((servent = getservbyname (servname, socktype)) != NULL) + port = ntohs (servent->s_port); + else + return EAI_NONAME; + + /* if nodename == NULL refer to the local host for a client or any + for a server */ + if (nodename == NULL) + { + struct sockaddr_in sin; + + /* check protocol family is PF_UNSPEC or PF_INET - could try harder + for IPv6 but that's more code than I'm prepared to write */ + if (hints->ai_family == PF_UNSPEC || hints->ai_family == PF_INET) + result.ai_family = AF_INET; + else + return EAI_FAMILY; + + sin.sin_family = result.ai_family; + sin.sin_port = htons (port); + if (hints->ai_flags & AI_PASSIVE) + sin.sin_addr.s_addr = htonl (INADDR_ANY); + else + sin.sin_addr.s_addr = htonl (INADDR_LOOPBACK); + /* Duplicate result and addr and return */ + *res = dup_addrinfo (&result, &sin, sizeof sin); + return (*res == NULL) ? EAI_MEMORY : 0; + } + + /* If AI_NUMERIC is specified, use inet_addr to translate numbers and + dots notation. */ + if (hints->ai_flags & AI_NUMERICHOST) + { + struct sockaddr_in sin; + + /* check protocol family is PF_UNSPEC or PF_INET */ + if (hints->ai_family == PF_UNSPEC || hints->ai_family == PF_INET) + result.ai_family = AF_INET; + else + return EAI_FAMILY; + + sin.sin_family = result.ai_family; + sin.sin_port = htons (port); + sin.sin_addr.s_addr = inet_addr (nodename); + /* Duplicate result and addr and return */ + *res = dup_addrinfo (&result, &sin, sizeof sin); + return (*res == NULL) ? EAI_MEMORY : 0; + } + + errno = 0; + hp = gethostbyname_ctx (nodename, &ghbnctx); + if (hp == NULL) + { + if (errno != 0) + { + free_ghbnctx (&ghbnctx); + return EAI_SYSTEM; + } + code = h_error_ctx (&ghbnctx); + switch (code) + { + case HOST_NOT_FOUND: code = EAI_NODATA; break; + case NO_DATA: code = EAI_NODATA; break; +#if defined(NO_ADDRESS) && NO_ADDRESS != NO_DATA + case NO_ADDRESS: code = EAI_NODATA; break; +#endif + case NO_RECOVERY: code = EAI_FAIL; break; + case TRY_AGAIN: code = EAI_AGAIN; break; + default: code = EAI_FAIL; break; + } + free_ghbnctx (&ghbnctx); + return code; + } + + /* Check that the address family is acceptable. + */ + switch (hp->h_addrtype) + { + case AF_INET: + if (!(hints->ai_family == PF_UNSPEC || hints->ai_family == PF_INET)) + goto eai_family; + break; +#ifdef USE_IPV6 + case AF_INET6: + if (!(hints->ai_family == PF_UNSPEC || hints->ai_family == PF_INET6)) + goto eai_family; + break; +#endif + default: + eai_family: + free_ghbnctx (&ghbnctx); + return EAI_FAMILY; + } + + /* For each element pointed to by hp, create an element in the + result linked list. */ + sai = eai = NULL; + for (addrs = hp->h_addr_list; *addrs != NULL; addrs++) + { + struct sockaddr sa; + size_t addrlen; + + if (hp->h_length < 1) + continue; + sa.sa_family = hp->h_addrtype; + switch (hp->h_addrtype) + { + case AF_INET: + ((struct sockaddr_in *) &sa)->sin_port = htons (port); + memcpy (&((struct sockaddr_in *) &sa)->sin_addr, + *addrs, hp->h_length); + addrlen = sizeof (struct sockaddr_in); + break; +#ifdef USE_IPV6 + case AF_INET6: +# if SIN6_LEN + ((struct sockaddr_in6 *) &sa)->sin6_len = hp->h_length; +# endif + ((struct sockaddr_in6 *) &sa)->sin6_port = htons (port); + memcpy (&((struct sockaddr_in6 *) &sa)->sin6_addr, + *addrs, hp->h_length); + addrlen = sizeof (struct sockaddr_in6); + break; +#endif + default: + continue; + } + + result.ai_family = hp->h_addrtype; + ai = dup_addrinfo (&result, &sa, addrlen); + if (ai == NULL) + { + free_ghbnctx (&ghbnctx); + freeaddrinfo (sai); + return EAI_MEMORY; + } + if (sai == NULL) + sai = ai; + else + eai->ai_next = ai; + eai = ai; + } + + if (sai == NULL) + { + free_ghbnctx (&ghbnctx); + return EAI_NODATA; + } + + if (hints->ai_flags & AI_CANONNAME) + { + sai->ai_canonname = malloc (strlen (hp->h_name) + 1); + if (sai->ai_canonname == NULL) + { + free_ghbnctx (&ghbnctx); + freeaddrinfo (sai); + return EAI_MEMORY; + } + strcpy (sai->ai_canonname, hp->h_name); + } + + free_ghbnctx (&ghbnctx); + *res = sai; + return 0; +} + +void +freeaddrinfo (struct addrinfo *ai) +{ + struct addrinfo *next; + + while (ai != NULL) + { + next = ai->ai_next; + if (ai->ai_canonname != NULL) + free (ai->ai_canonname); + if (ai->ai_addr != NULL) + free (ai->ai_addr); + free (ai); + ai = next; + } +} + +const char * +gai_strerror (int ecode) +{ + static const char *eai_descr[] = + { + "no error", + "address family for nodename not supported", /* EAI_ADDRFAMILY */ + "temporary failure in name resolution", /* EAI_AGAIN */ + "invalid value for ai_flags", /* EAI_BADFLAGS */ + "non-recoverable failure in name resolution", /* EAI_FAIL */ + "ai_family not supported", /* EAI_FAMILY */ + "memory allocation failure", /* EAI_MEMORY */ + "no address associated with nodename", /* EAI_NODATA */ + "nodename nor servname provided, or not known", /* EAI_NONAME */ + "servname not supported for ai_socktype", /* EAI_SERVICE */ + "ai_socktype not supported", /* EAI_SOCKTYPE */ + "system error returned in errno", /* EAI_SYSTEM */ + }; + + if (ecode < 0 || ecode > (int) (sizeof eai_descr/ sizeof eai_descr[0])) + return "unknown error"; + return eai_descr[ecode]; +} + |