diff options
Diffstat (limited to 'src/gns/nss/nss_gns.c')
| -rw-r--r-- | src/gns/nss/nss_gns.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/src/gns/nss/nss_gns.c b/src/gns/nss/nss_gns.c new file mode 100644 index 0000000..3bb45a1 --- /dev/null +++ b/src/gns/nss/nss_gns.c @@ -0,0 +1,264 @@ +/*** + This file is part of nss-gns. + + Parts taken from: nss.c in 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 distributed in the hope that it will be useful, but1 + 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. +***/ + +#include <gnunet_config.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> +#include <assert.h> +#include <netdb.h> +#include <sys/socket.h> +#include <nss.h> +#include <stdio.h> +#include <stdlib.h> + +#include "nss_gns_query.h" + +#include <arpa/inet.h> + +/** macro to align idx to 32bit boundary */ +#define ALIGN(idx) do { \ + if (idx % sizeof(void*)) \ + idx += (sizeof(void*) - idx % sizeof(void*)); /* Align on 32 bit boundary */ \ +} while(0) + + +/** + * function to check if name ends with a specific suffix + * + * @param name the name to check + * @param suffix the suffix to check for + * @return 1 if true + */ +static int ends_with(const char *name, const char* suffix) { + size_t ln, ls; + assert(name); + assert(suffix); + + if ((ls = strlen(suffix)) > (ln = strlen(name))) + return 0; + + return strcasecmp(name+ln-ls, suffix) == 0; +} + + +/** + * Check if name is inside .gnunet or .zkey TLD + * + * @param name name to check + * @return 1 if true + */ +static int verify_name_allowed(const char *name) { + return ends_with(name, ".gnunet") || ends_with(name, ".zkey"); +} + +/** + * The gethostbyname hook executed by nsswitch + * + * @param name the name to resolve + * @param af the address family to resolve + * @param result the result hostent + * @param buffer the result buffer + * @param buflen length of the buffer + * @param errnop idk + * @param h_errnop idk + * @return a nss_status code + */ +enum nss_status _nss_gns_gethostbyname2_r( + const char *name, + int af, + struct hostent * result, + char *buffer, + size_t buflen, + int *errnop, + int *h_errnop) { + + struct userdata u; + enum nss_status status = NSS_STATUS_UNAVAIL; + int i; + size_t address_length, l, idx, astart; + int name_allowed; + + if (af == AF_UNSPEC) +#ifdef NSS_IPV6_ONLY + af = AF_INET6; +#else + af = AF_INET; +#endif + +#ifdef NSS_IPV4_ONLY + if (af != AF_INET) +#elif NSS_IPV6_ONLY + if (af != AF_INET6) +#else + if (af != AF_INET && af != AF_INET6) +#endif + { + *errnop = EINVAL; + *h_errnop = NO_RECOVERY; + + goto finish; + } + + address_length = af == AF_INET ? sizeof(ipv4_address_t) : sizeof(ipv6_address_t); + if (buflen < + sizeof(char*)+ /* alias names */ + strlen(name)+1) { /* official name */ + + *errnop = ERANGE; + *h_errnop = NO_RECOVERY; + status = NSS_STATUS_TRYAGAIN; + + goto finish; + } + + u.count = 0; + u.data_len = 0; + + name_allowed = verify_name_allowed(name); + + if (name_allowed) { + + if (!gns_resolve_name(af, name, &u) == 0) + { + status = NSS_STATUS_NOTFOUND; + } + } + + if (u.count == 0) { + *errnop = ETIMEDOUT; + *h_errnop = HOST_NOT_FOUND; + printf("not found\n"); + goto finish; + } + + + /* Alias names */ + *((char**) buffer) = NULL; + result->h_aliases = (char**) buffer; + idx = sizeof(char*); + + /* Official name */ + strcpy(buffer+idx, name); + result->h_name = buffer+idx; + idx += strlen(name)+1; + + ALIGN(idx); + + result->h_addrtype = af; + result->h_length = address_length; + + /* Check if there's enough space for the addresses */ + if (buflen < idx+u.data_len+sizeof(char*)*(u.count+1)) { + *errnop = ERANGE; + *h_errnop = NO_RECOVERY; + status = NSS_STATUS_TRYAGAIN; + goto finish; + } + + /* Addresses */ + astart = idx; + l = u.count*address_length; + memcpy(buffer+astart, &u.data, l); + /* address_length is a multiple of 32bits, so idx is still aligned + * correctly */ + idx += l; + + /* Address array address_lenght is always a multiple of 32bits */ + for (i = 0; i < u.count; i++) + ((char**) (buffer+idx))[i] = buffer+astart+address_length*i; + ((char**) (buffer+idx))[i] = NULL; + result->h_addr_list = (char**) (buffer+idx); + + status = NSS_STATUS_SUCCESS; + +finish: + return status; +} + +/** + * The gethostbyname hook executed by nsswitch + * + * @param name the name to resolve + * @param result the result hostent + * @param buffer the result buffer + * @param buflen length of the buffer + * @param errnop idk + * @param h_errnop idk + * @return a nss_status code + */ +enum nss_status _nss_gns_gethostbyname_r ( + const char *name, + struct hostent *result, + char *buffer, + size_t buflen, + int *errnop, + int *h_errnop) { + + return _nss_gns_gethostbyname2_r( + name, + AF_UNSPEC, + result, + buffer, + buflen, + errnop, + h_errnop); +} + +/** + * The gethostbyaddr hook executed by nsswitch + * We can't do this so we always return NSS_STATUS_UNAVAIL + * + * @param addr the address to resolve + * @param len the length of the address + * @param af the address family of the address + * @param result the result hostent + * @param buffer the result buffer + * @param buflen length of the buffer + * @param errnop idk + * @param h_errnop idk + * @return NSS_STATUS_UNAVAIL + */ +enum nss_status _nss_gns_gethostbyaddr_r( + const void* addr, + int len, + int af, + struct hostent *result, + char *buffer, + size_t buflen, + int *errnop, + int *h_errnop) { + + /* we dont do this */ + + enum nss_status status = NSS_STATUS_UNAVAIL; + + *errnop = EINVAL; + *h_errnop = NO_RECOVERY; + + /* Check for address types */ + + *h_errnop = NO_RECOVERY; + + status = NSS_STATUS_NOTFOUND; + return status; +} + |