diff options
Diffstat (limited to 'src/c-ares/ares_getnameinfo.c')
| -rw-r--r-- | src/c-ares/ares_getnameinfo.c | 422 |
1 files changed, 422 insertions, 0 deletions
diff --git a/src/c-ares/ares_getnameinfo.c b/src/c-ares/ares_getnameinfo.c new file mode 100644 index 00000000..45161124 --- /dev/null +++ b/src/c-ares/ares_getnameinfo.c @@ -0,0 +1,422 @@ + +/* Copyright 2005 by Dominick Meglio + * + * Permission to use, copy, modify, and distribute this + * software and its documentation for any purpose and without + * fee is hereby granted, provided that the above copyright + * notice appear in all copies and that both that copyright + * notice and this permission notice appear in supporting + * documentation, and that the name of M.I.T. not be used in + * advertising or publicity pertaining to distribution of the + * software without specific, written prior permission. + * M.I.T. makes no representations about the suitability of + * this software for any purpose. It is provided "as is" + * without express or implied warranty. + */ +#include "ares_setup.h" + +#ifdef HAVE_GETSERVBYPORT_R +# if !defined(GETSERVBYPORT_R_ARGS) || \ + (GETSERVBYPORT_R_ARGS < 4) || (GETSERVBYPORT_R_ARGS > 6) +# error "you MUST specifiy a valid number of arguments for getservbyport_r" +# endif +#endif + +#ifdef HAVE_NETINET_IN_H +# include <netinet/in.h> +#endif +#ifdef HAVE_NETDB_H +# include <netdb.h> +#endif +#ifdef HAVE_ARPA_INET_H +# include <arpa/inet.h> +#endif +#ifdef HAVE_ARPA_NAMESER_H +# include <arpa/nameser.h> +#else +# include "nameser.h" +#endif +#ifdef HAVE_ARPA_NAMESER_COMPAT_H +# include <arpa/nameser_compat.h> +#endif + +#ifdef HAVE_NET_IF_H +#include <net/if.h> +#endif + +#include "ares.h" +#include "ares_ipv6.h" +#include "ares_nowarn.h" +#include "ares_private.h" + +struct nameinfo_query { + ares_nameinfo_callback callback; + void *arg; + union { + struct sockaddr_in addr4; + struct sockaddr_in6 addr6; + } addr; + int family; + int flags; + int timeouts; +}; + +#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID +#define IPBUFSIZ \ + (sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255") + IF_NAMESIZE) +#else +#define IPBUFSIZ \ + (sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")) +#endif + +static void nameinfo_callback(void *arg, int status, int timeouts, + struct hostent *host); +static char *lookup_service(unsigned short port, int flags, + char *buf, size_t buflen); +#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID +static void append_scopeid(struct sockaddr_in6 *addr6, unsigned int scopeid, + char *buf, size_t buflen); +#endif +STATIC_TESTABLE char *ares_striendstr(const char *s1, const char *s2); + +void ares_getnameinfo(ares_channel channel, const struct sockaddr *sa, + ares_socklen_t salen, + int flags, ares_nameinfo_callback callback, void *arg) +{ + struct sockaddr_in *addr = NULL; + struct sockaddr_in6 *addr6 = NULL; + struct nameinfo_query *niquery; + unsigned int port = 0; + + /* Validate socket address family and length */ + if ((sa->sa_family == AF_INET) && + (salen == sizeof(struct sockaddr_in))) + { + addr = (struct sockaddr_in *)sa; + port = addr->sin_port; + } + else if ((sa->sa_family == AF_INET6) && + (salen == sizeof(struct sockaddr_in6))) + { + addr6 = (struct sockaddr_in6 *)sa; + port = addr6->sin6_port; + } + else + { + callback(arg, ARES_ENOTIMP, 0, NULL, NULL); + return; + } + + /* If neither, assume they want a host */ + if (!(flags & ARES_NI_LOOKUPSERVICE) && !(flags & ARES_NI_LOOKUPHOST)) + flags |= ARES_NI_LOOKUPHOST; + + /* All they want is a service, no need for DNS */ + if ((flags & ARES_NI_LOOKUPSERVICE) && !(flags & ARES_NI_LOOKUPHOST)) + { + char buf[33], *service; + + service = lookup_service((unsigned short)(port & 0xffff), + flags, buf, sizeof(buf)); + callback(arg, ARES_SUCCESS, 0, NULL, service); + return; + } + + /* They want a host lookup */ + if ((flags & ARES_NI_LOOKUPHOST)) + { + /* A numeric host can be handled without DNS */ + if ((flags & ARES_NI_NUMERICHOST)) + { + char ipbuf[IPBUFSIZ]; + char srvbuf[33]; + char *service = NULL; + ipbuf[0] = 0; + + /* Specifying not to lookup a host, but then saying a host + * is required has to be illegal. + */ + if (flags & ARES_NI_NAMEREQD) + { + callback(arg, ARES_EBADFLAGS, 0, NULL, NULL); + return; + } + if (salen == sizeof(struct sockaddr_in6)) + { + ares_inet_ntop(AF_INET6, &addr6->sin6_addr, ipbuf, IPBUFSIZ); + /* If the system supports scope IDs, use it */ +#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID + append_scopeid(addr6, flags, ipbuf, sizeof(ipbuf)); +#endif + } + else + { + ares_inet_ntop(AF_INET, &addr->sin_addr, ipbuf, IPBUFSIZ); + } + /* They also want a service */ + if (flags & ARES_NI_LOOKUPSERVICE) + service = lookup_service((unsigned short)(port & 0xffff), + flags, srvbuf, sizeof(srvbuf)); + callback(arg, ARES_SUCCESS, 0, ipbuf, service); + return; + } + /* This is where a DNS lookup becomes necessary */ + else + { + niquery = ares_malloc(sizeof(struct nameinfo_query)); + if (!niquery) + { + callback(arg, ARES_ENOMEM, 0, NULL, NULL); + return; + } + niquery->callback = callback; + niquery->arg = arg; + niquery->flags = flags; + niquery->timeouts = 0; + if (sa->sa_family == AF_INET) + { + niquery->family = AF_INET; + memcpy(&niquery->addr.addr4, addr, sizeof(niquery->addr.addr4)); + ares_gethostbyaddr(channel, &addr->sin_addr, + sizeof(struct in_addr), AF_INET, + nameinfo_callback, niquery); + } + else + { + niquery->family = AF_INET6; + memcpy(&niquery->addr.addr6, addr6, sizeof(niquery->addr.addr6)); + ares_gethostbyaddr(channel, &addr6->sin6_addr, + sizeof(struct ares_in6_addr), AF_INET6, + nameinfo_callback, niquery); + } + } + } +} + +static void nameinfo_callback(void *arg, int status, int timeouts, + struct hostent *host) +{ + struct nameinfo_query *niquery = (struct nameinfo_query *) arg; + char srvbuf[33]; + char *service = NULL; + + niquery->timeouts += timeouts; + if (status == ARES_SUCCESS) + { + /* They want a service too */ + if (niquery->flags & ARES_NI_LOOKUPSERVICE) + { + if (niquery->family == AF_INET) + service = lookup_service(niquery->addr.addr4.sin_port, + niquery->flags, srvbuf, sizeof(srvbuf)); + else + service = lookup_service(niquery->addr.addr6.sin6_port, + niquery->flags, srvbuf, sizeof(srvbuf)); + } + /* NOFQDN means we have to strip off the domain name portion. We do + this by determining our own domain name, then searching the string + for this domain name and removing it. + */ +#ifdef HAVE_GETHOSTNAME + if (niquery->flags & ARES_NI_NOFQDN) + { + char buf[255]; + char *domain; + gethostname(buf, 255); + if ((domain = strchr(buf, '.')) != NULL) + { + char *end = ares_striendstr(host->h_name, domain); + if (end) + *end = 0; + } + } +#endif + niquery->callback(niquery->arg, ARES_SUCCESS, niquery->timeouts, + (char *)(host->h_name), + service); + ares_free(niquery); + return; + } + /* We couldn't find the host, but it's OK, we can use the IP */ + else if (status == ARES_ENOTFOUND && !(niquery->flags & ARES_NI_NAMEREQD)) + { + char ipbuf[IPBUFSIZ]; + if (niquery->family == AF_INET) + ares_inet_ntop(AF_INET, &niquery->addr.addr4.sin_addr, ipbuf, + IPBUFSIZ); + else + { + ares_inet_ntop(AF_INET6, &niquery->addr.addr6.sin6_addr, ipbuf, + IPBUFSIZ); +#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID + append_scopeid(&niquery->addr.addr6, niquery->flags, ipbuf, + sizeof(ipbuf)); +#endif + } + /* They want a service too */ + if (niquery->flags & ARES_NI_LOOKUPSERVICE) + { + if (niquery->family == AF_INET) + service = lookup_service(niquery->addr.addr4.sin_port, + niquery->flags, srvbuf, sizeof(srvbuf)); + else + service = lookup_service(niquery->addr.addr6.sin6_port, + niquery->flags, srvbuf, sizeof(srvbuf)); + } + niquery->callback(niquery->arg, ARES_SUCCESS, niquery->timeouts, ipbuf, + service); + ares_free(niquery); + return; + } + niquery->callback(niquery->arg, status, niquery->timeouts, NULL, NULL); + ares_free(niquery); +} + +static char *lookup_service(unsigned short port, int flags, + char *buf, size_t buflen) +{ + const char *proto; + struct servent *sep; +#ifdef HAVE_GETSERVBYPORT_R + struct servent se; +#endif + char tmpbuf[4096]; + char *name; + size_t name_len; + + if (port) + { + if (flags & ARES_NI_NUMERICSERV) + sep = NULL; + else + { + if (flags & ARES_NI_UDP) + proto = "udp"; + else if (flags & ARES_NI_SCTP) + proto = "sctp"; + else if (flags & ARES_NI_DCCP) + proto = "dccp"; + else + proto = "tcp"; +#ifdef HAVE_GETSERVBYPORT_R + memset(&se, 0, sizeof(se)); + sep = &se; + memset(tmpbuf, 0, sizeof(tmpbuf)); +#if GETSERVBYPORT_R_ARGS == 6 + if (getservbyport_r(port, proto, &se, (void *)tmpbuf, + sizeof(tmpbuf), &sep) != 0) + sep = NULL; /* LCOV_EXCL_LINE: buffer large so this never fails */ +#elif GETSERVBYPORT_R_ARGS == 5 + sep = getservbyport_r(port, proto, &se, (void *)tmpbuf, + sizeof(tmpbuf)); +#elif GETSERVBYPORT_R_ARGS == 4 + if (getservbyport_r(port, proto, &se, (void *)tmpbuf) != 0) + sep = NULL; +#else + /* Lets just hope the OS uses TLS! */ + sep = getservbyport(port, proto); +#endif +#else + /* Lets just hope the OS uses TLS! */ +#if (defined(NETWARE) && !defined(__NOVELL_LIBC__)) + sep = getservbyport(port, (char*)proto); +#else + sep = getservbyport(port, proto); +#endif +#endif + } + if (sep && sep->s_name) + { + /* get service name */ + name = sep->s_name; + } + else + { + /* get port as a string */ + sprintf(tmpbuf, "%u", (unsigned int)ntohs(port)); + name = tmpbuf; + } + name_len = strlen(name); + if (name_len < buflen) + /* return it if buffer big enough */ + memcpy(buf, name, name_len + 1); + else + /* avoid reusing previous one */ + buf[0] = '\0'; /* LCOV_EXCL_LINE: no real service names are too big */ + return buf; + } + buf[0] = '\0'; + return NULL; +} + +#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID +static void append_scopeid(struct sockaddr_in6 *addr6, unsigned int flags, + char *buf, size_t buflen) +{ +#ifdef HAVE_IF_INDEXTONAME + int is_ll, is_mcll; +#endif + static const char fmt_u[] = "%u"; + static const char fmt_lu[] = "%lu"; + char tmpbuf[IF_NAMESIZE + 2]; + size_t bufl; + const char *fmt = (sizeof(addr6->sin6_scope_id) > sizeof(unsigned int))? + fmt_lu:fmt_u; + + tmpbuf[0] = '%'; + +#ifdef HAVE_IF_INDEXTONAME + is_ll = IN6_IS_ADDR_LINKLOCAL(&addr6->sin6_addr); + is_mcll = IN6_IS_ADDR_MC_LINKLOCAL(&addr6->sin6_addr); + if ((flags & ARES_NI_NUMERICSCOPE) || + (!is_ll && !is_mcll)) + { + sprintf(&tmpbuf[1], fmt, addr6->sin6_scope_id); + } + else + { + if (if_indextoname(addr6->sin6_scope_id, &tmpbuf[1]) == NULL) + sprintf(&tmpbuf[1], fmt, addr6->sin6_scope_id); + } +#else + sprintf(&tmpbuf[1], fmt, addr6->sin6_scope_id); + (void) flags; +#endif + tmpbuf[IF_NAMESIZE + 1] = '\0'; + bufl = strlen(buf); + + if(bufl + strlen(tmpbuf) < buflen) + /* only append the scopeid string if it fits in the target buffer */ + strcpy(&buf[bufl], tmpbuf); +} +#endif + +/* Determines if s1 ends with the string in s2 (case-insensitive) */ +STATIC_TESTABLE char *ares_striendstr(const char *s1, const char *s2) +{ + const char *c1, *c2, *c1_begin; + int lo1, lo2; + size_t s1_len = strlen(s1), s2_len = strlen(s2); + + /* If the substr is longer than the full str, it can't match */ + if (s2_len > s1_len) + return NULL; + + /* Jump to the end of s1 minus the length of s2 */ + c1_begin = s1+s1_len-s2_len; + c1 = (const char *)c1_begin; + c2 = s2; + while (c2 < s2+s2_len) + { + lo1 = TOLOWER(*c1); + lo2 = TOLOWER(*c2); + if (lo1 != lo2) + return NULL; + else + { + c1++; + c2++; + } + } + return (char *)c1_begin; +} |