diff options
Diffstat (limited to 'src/nss.c')
| -rw-r--r-- | src/nss.c | 319 |
1 files changed, 257 insertions, 62 deletions
@@ -1,22 +1,22 @@ /* $Id$ */ /*** - This file is part of nss-mdns. + This file is part of nss-mdns. - nss-mdns 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 of the License, - or (at your option) any later version. + nss-mdns 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 of the License, + or (at your option) any later version. - nss-mdns 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 - General Public License for more details. + nss-mdns 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 + General Public License for more details. - You should have received a copy of the GNU Lesser General Public License - along with nss-mdns; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 - USA. + You should have received a copy of the GNU Lesser General Public License + along with nss-mdns; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + USA. ***/ #ifdef HAVE_CONFIG_H @@ -31,6 +31,7 @@ #include <sys/socket.h> #include <nss.h> #include <stdio.h> +#include <stdlib.h> #include "query.h" @@ -50,6 +51,9 @@ #define _nss_mdns_gethostbyaddr_r _nss_mdns6_gethostbyaddr_r #endif +/* the resolv conf page states that they only support 6 domains */ +#define MAX_SEARCH_DOMAINS 6 + struct userdata { int count; int data_len; /* only valid when doing reverse lookup */ @@ -149,6 +153,110 @@ static int verify_name_allowed(const char *name) { return valid; } +static char **alloc_domains(unsigned ndomains) { + char **domains; + + if (!(domains = malloc(sizeof(char*) * ndomains))) + return NULL; + + /* initialize them all to 0 */ + memset(domains, 0, sizeof(char*) * ndomains); + return domains; +} + +static void free_domains(char **domains) { + char **p; + + if (!domains) + return; + + for(p = domains; *p; p++) + free(*p); + + free(domains); +} + +static char** parse_domains(const char *domains_in) { + /* leave room for the NULL terminator */ + char **domains_out; + const char *start = domains_in; + unsigned domain = 0; + + if (!(domains_out = alloc_domains(MAX_SEARCH_DOMAINS+1))) + return NULL; + + while (domain < MAX_SEARCH_DOMAINS) { + const char *end; + char *tmp; + size_t domain_len; + + end = start + strcspn(start, " \t\r\n"); + domain_len = (end - start); + + if (!(tmp = malloc(domain_len + 1))) + break; + + memcpy(tmp, start, domain_len); + tmp[domain_len] = '\0'; + + domains_out[domain++] = tmp; + + end += strspn(end," \t\r\n"); + + if (!*end) + break; + + start = end; + } + + return domains_out; +} + +static char** get_search_domains(void) { + FILE *f = 0; + char **domains = NULL; + + /* according to the resolv.conf man page (in Linux) the LOCALDOMAIN + environment variable should override the settings in the resolv.conf file */ + char *line = getenv("LOCALDOMAIN"); + if (line && *line != 0) + return parse_domains(line); + + if (!(f = fopen(RESOLV_CONF_FILE, "r"))) + return NULL; + + while (!feof(f)) { + char *start = NULL; + char ln[512]; + + if (!fgets(ln, sizeof(ln), f)) + break; + + start = ln + strspn(ln, " \t\r\n"); + + if (strncmp(start, "search", 6) && strncmp(start, "domain", 6)) + continue; + + if (start[6] != ' ' && start[6] != '\t') + continue; + + /* scan to the end of the keyword ('search' or 'domain' currently) */ + start += strcspn(start, " \t\r\n"); + + /* find the begining of the first domain in the list */ + start += strspn(start, " \t\r\n"); + + /* the resolv.conf manpage also states that 'search' and 'domain' are mutually exclusive + and that the last one wins. */ + free_domains(domains); + domains = parse_domains(start); + } + + fclose(f); + + return domains; +} + enum nss_status _nss_mdns_gethostbyname2_r( const char *name, int af, @@ -160,12 +268,14 @@ enum nss_status _nss_mdns_gethostbyname2_r( struct userdata u; enum nss_status status = NSS_STATUS_UNAVAIL; - int fd = -1, r, i; - size_t address_length, l, index, astart; + int fd = -1, i; + size_t address_length, l, idx, astart; void (*ipv4_func)(const ipv4_address_t *ipv4, void *userdata); void (*ipv6_func)(const ipv6_address_t *ipv6, void *userdata); + int name_allowed; #ifdef ENABLE_AVAHI + int avahi_works = 1; uint8_t data[128]; #endif @@ -184,13 +294,6 @@ enum nss_status _nss_mdns_gethostbyname2_r( goto finish; } - if (! verify_name_allowed(name)) { - *errnop = ENOENT; - *h_errnop = HOST_NOT_FOUND; - status = NSS_STATUS_NOTFOUND; - goto finish; - } - address_length = af == AF_INET ? sizeof(ipv4_address_t) : sizeof(ipv6_address_t); if (buflen < sizeof(char*)+ /* alias names */ @@ -218,51 +321,143 @@ enum nss_status _nss_mdns_gethostbyname2_r( ipv6_func = af == AF_INET6 ? ipv6_callback : NULL; #endif + name_allowed = verify_name_allowed(name); + #ifdef ENABLE_AVAHI - if ((r = avahi_resolve_name(af, name, data)) == 0) { - if (af == AF_INET && ipv4_func) - ipv4_func((ipv4_address_t*) data, &u); - if (af == AF_INET6 && ipv4_func) - ipv6_func((ipv6_address_t*)data, &u); - } else if (r > 0) { - *errnop = ETIMEDOUT; - *h_errnop = HOST_NOT_FOUND; - goto finish; + if (avahi_works && name_allowed) { + int r; + + if ((r = avahi_resolve_name(af, name, data)) < 0) + avahi_works = 0; + else if (r == 0) { + if (af == AF_INET && ipv4_func) + ipv4_func((ipv4_address_t*) data, &u); + if (af == AF_INET6 && ipv6_func) + ipv6_func((ipv6_address_t*)data, &u); + } + } - + + if (u.count == 0 && avahi_works && !ends_with(name, ".")) { + char **domains; + + if ((domains = get_search_domains())) { + char **p; + + /* Try to concatenate host names */ + for (p = domains; *p; p++) { + int fullnamesize; + char *fullname; + + fullnamesize = strlen(name) + strlen(*p) + 2; + + if (!(fullname = malloc(fullnamesize))) + break; + + snprintf(fullname, fullnamesize, "%s.%s", name, *p); + + if (verify_name_allowed(fullname)) { + int r; + + r = avahi_resolve_name(af, fullname, data); + free(fullname); + + if (r < 0) { + avahi_works = 0; + break; + } else if (r == 0) { + if (af == AF_INET && ipv4_func) + ipv4_func((ipv4_address_t*) data, &u); + if (af == AF_INET6 && ipv6_func) + ipv6_func((ipv6_address_t*)data, &u); + break; + } + + } else + free(fullname); + } + + free_domains(domains); + } + } + + + if (u.count == 0 && !avahi_works) { #endif - if (u.count == 0) { if ((fd = mdns_open_socket()) < 0) { - *errnop = errno; *h_errnop = NO_RECOVERY; goto finish; } - - if ((r = mdns_query_name(fd, name, ipv4_func, ipv6_func, &u)) < 0) { - *errnop = ETIMEDOUT; - *h_errnop = HOST_NOT_FOUND; - goto finish; + + if (name_allowed) + /* Ignore return value */ + mdns_query_name(fd, name, ipv4_func, ipv6_func, &u); + + if (u.count == 0 && !ends_with(name, ".")) { + char **domains; + + /* Try the search domains if the user did not use a traling '.' */ + + if ((domains = get_search_domains())) { + char **p; + + for (p = domains; *p; p++) { + int fullnamesize = 0; + char *fullname = NULL; + + fullnamesize = strlen(name) + strlen(*p) + 2; + if (!(fullname = malloc(fullnamesize))) + break; + + snprintf(fullname, fullnamesize, "%s.%s", name, *p); + + if (verify_name_allowed(fullname)) { + + /* Ignore return value */ + mdns_query_name(fd, fullname, ipv4_func, ipv6_func, &u); + + if (u.count > 0) { + /* We found somethings, so let's quit */ + free(fullname); + break; + } + } + + free(fullname); + } + + free_domains(domains); + } } + +#ifdef ENABLE_AVAHI } - +#endif + + if (u.count == 0) { + *errnop = ETIMEDOUT; + *h_errnop = HOST_NOT_FOUND; + goto finish; + } + /* Alias names */ *((char**) buffer) = NULL; result->h_aliases = (char**) buffer; - index = sizeof(char*); + idx = sizeof(char*); /* Official name */ - strcpy(buffer+index, name); - result->h_name = buffer+index; - index += strlen(name)+1; + strcpy(buffer+idx, name); + result->h_name = buffer+idx; + idx += strlen(name)+1; result->h_addrtype = af; result->h_length = address_length; /* Check if there's enough space for the addresses */ - if (buflen < index+u.data_len+sizeof(char*)*(u.count+1)) { + if (buflen < idx+u.data_len+sizeof(char*)*(u.count+1)) { *errnop = ERANGE; *h_errnop = NO_RECOVERY; status = NSS_STATUS_TRYAGAIN; @@ -270,17 +465,17 @@ enum nss_status _nss_mdns_gethostbyname2_r( } /* Addresses */ - astart = index; + astart = idx; l = u.count*address_length; memcpy(buffer+astart, &u.data, l); - index += l; + idx += l; /* Address array */ for (i = 0; i < u.count; i++) - ((char**) (buffer+index))[i] = buffer+astart+address_length*i; - ((char**) (buffer+index))[i] = NULL; + ((char**) (buffer+idx))[i] = buffer+astart+address_length*i; + ((char**) (buffer+idx))[i] = NULL; - result->h_addr_list = (char**) (buffer+index); + result->h_addr_list = (char**) (buffer+idx); status = NSS_STATUS_SUCCESS; @@ -326,7 +521,7 @@ enum nss_status _nss_mdns_gethostbyaddr_r( struct userdata u; enum nss_status status = NSS_STATUS_UNAVAIL; int fd = -1, r; - size_t address_length, index, astart; + size_t address_length, idx, astart; #ifdef ENABLE_AVAHI char t[256]; #endif @@ -389,13 +584,13 @@ enum nss_status _nss_mdns_gethostbyaddr_r( if (af == AF_INET) #endif #ifndef NSS_IPV6_ONLY - r = mdns_query_ipv4(fd, (ipv4_address_t*) addr, name_callback, &u); + r = mdns_query_ipv4(fd, (const ipv4_address_t*) addr, name_callback, &u); #endif #if ! defined(NSS_IPV6_ONLY) && ! defined(NSS_IPV4_ONLY) else #endif #ifndef NSS_IPV4_ONLY - r = mdns_query_ipv6(fd, (ipv6_address_t*) addr, name_callback, &u); + r = mdns_query_ipv6(fd, (const ipv6_address_t*) addr, name_callback, &u); #endif if (r < 0) { @@ -408,7 +603,7 @@ enum nss_status _nss_mdns_gethostbyaddr_r( /* Alias names */ *((char**) buffer) = NULL; result->h_aliases = (char**) buffer; - index = sizeof(char*); + idx = sizeof(char*); assert(u.count > 0 && u.data.name[0]); if (buflen < @@ -424,22 +619,22 @@ enum nss_status _nss_mdns_gethostbyaddr_r( } /* Official name */ - strcpy(buffer+index, u.data.name[0]); - result->h_name = buffer+index; - index += strlen(u.data.name[0])+1; + strcpy(buffer+idx, u.data.name[0]); + result->h_name = buffer+idx; + idx += strlen(u.data.name[0])+1; result->h_addrtype = af; result->h_length = address_length; /* Address */ - astart = index; + astart = idx; memcpy(buffer+astart, addr, address_length); - index += address_length; + idx += address_length; /* Address array */ - ((char**) (buffer+index))[0] = buffer+astart; - ((char**) (buffer+index))[1] = NULL; - result->h_addr_list = (char**) (buffer+index); + ((char**) (buffer+idx))[0] = buffer+astart; + ((char**) (buffer+idx))[1] = NULL; + result->h_addr_list = (char**) (buffer+idx); status = NSS_STATUS_SUCCESS; |