| /* Copyright (C) 2007-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@redhat.com>, 2007. |
| |
| The GNU C 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. |
| |
| The GNU C 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 the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <not-cancel.h> |
| #include <_itoa.h> |
| #include <stdint.h> |
| |
| #include "nscd-client.h" |
| #include "nscd_proto.h" |
| |
| |
| int __nss_not_use_nscd_services; |
| |
| |
| static int nscd_getserv_r (const char *crit, size_t critlen, const char *proto, |
| request_type type, struct servent *resultbuf, |
| char *buf, size_t buflen, struct servent **result); |
| |
| |
| int |
| __nscd_getservbyname_r (const char *name, const char *proto, |
| struct servent *result_buf, char *buf, size_t buflen, |
| struct servent **result) |
| { |
| return nscd_getserv_r (name, strlen (name), proto, GETSERVBYNAME, result_buf, |
| buf, buflen, result); |
| } |
| |
| |
| int |
| __nscd_getservbyport_r (int port, const char *proto, |
| struct servent *result_buf, char *buf, size_t buflen, |
| struct servent **result) |
| { |
| char portstr[3 * sizeof (int) + 2]; |
| portstr[sizeof (portstr) - 1] = '\0'; |
| char *cp = _itoa_word (port, portstr + sizeof (portstr) - 1, 10, 0); |
| |
| return nscd_getserv_r (cp, portstr + sizeof (portstr) - 1 - cp, proto, |
| GETSERVBYPORT, result_buf, buf, buflen, result); |
| } |
| |
| |
| libc_locked_map_ptr (, __serv_map_handle) attribute_hidden; |
| /* Note that we only free the structure if necessary. The memory |
| mapping is not removed since it is not visible to the malloc |
| handling. */ |
| libc_freeres_fn (serv_map_free) |
| { |
| if (__serv_map_handle.mapped != NO_MAPPING) |
| { |
| void *p = __serv_map_handle.mapped; |
| __serv_map_handle.mapped = NO_MAPPING; |
| free (p); |
| } |
| } |
| |
| |
| static int |
| nscd_getserv_r (const char *crit, size_t critlen, const char *proto, |
| request_type type, struct servent *resultbuf, |
| char *buf, size_t buflen, struct servent **result) |
| { |
| int gc_cycle; |
| int nretries = 0; |
| size_t alloca_used = 0; |
| |
| /* If the mapping is available, try to search there instead of |
| communicating with the nscd. */ |
| struct mapped_database *mapped; |
| mapped = __nscd_get_map_ref (GETFDSERV, "services", &__serv_map_handle, |
| &gc_cycle); |
| size_t protolen = proto == NULL ? 0 : strlen (proto); |
| size_t keylen = critlen + 1 + protolen + 1; |
| int alloca_key = __libc_use_alloca (keylen); |
| char *key; |
| if (alloca_key) |
| key = alloca_account (keylen, alloca_used); |
| else |
| { |
| key = malloc (keylen); |
| if (key == NULL) |
| return -1; |
| } |
| memcpy (__mempcpy (__mempcpy (key, crit, critlen), |
| "/", 1), proto ?: "", protolen + 1); |
| |
| retry:; |
| const char *s_name = NULL; |
| const char *s_proto = NULL; |
| int alloca_aliases_len = 0; |
| const uint32_t *aliases_len = NULL; |
| const char *aliases_list = NULL; |
| int retval = -1; |
| const char *recend = (const char *) ~UINTMAX_C (0); |
| int sock = -1; |
| serv_response_header serv_resp; |
| |
| if (mapped != NO_MAPPING) |
| { |
| struct datahead *found = __nscd_cache_search (type, key, keylen, mapped, |
| sizeof serv_resp); |
| |
| if (found != NULL) |
| { |
| s_name = (char *) (&found->data[0].servdata + 1); |
| serv_resp = found->data[0].servdata; |
| s_proto = s_name + serv_resp.s_name_len; |
| alloca_aliases_len = 1; |
| aliases_len = (uint32_t *) (s_proto + serv_resp.s_proto_len); |
| aliases_list = ((char *) aliases_len |
| + serv_resp.s_aliases_cnt * sizeof (uint32_t)); |
| recend = (const char *) found->data + found->recsize; |
| /* Now check if we can trust serv_resp fields. If GC is |
| in progress, it can contain anything. */ |
| if (mapped->head->gc_cycle != gc_cycle) |
| { |
| retval = -2; |
| goto out; |
| } |
| if (__builtin_expect ((const char *) aliases_len |
| + serv_resp.s_aliases_cnt * sizeof (uint32_t) |
| > recend, 0)) |
| goto out; |
| |
| #if !_STRING_ARCH_unaligned |
| /* The aliases_len array in the mapped database might very |
| well be unaligned. We will access it word-wise so on |
| platforms which do not tolerate unaligned accesses we |
| need to make an aligned copy. */ |
| if (((uintptr_t) aliases_len & (__alignof__ (*aliases_len) - 1)) |
| != 0) |
| { |
| uint32_t *tmp; |
| alloca_aliases_len |
| = __libc_use_alloca (alloca_used |
| + (serv_resp.s_aliases_cnt |
| * sizeof (uint32_t))); |
| if (alloca_aliases_len) |
| tmp = alloca_account (serv_resp.s_aliases_cnt |
| * sizeof (uint32_t), |
| alloca_used); |
| else |
| { |
| tmp = malloc (serv_resp.s_aliases_cnt * sizeof (uint32_t)); |
| if (tmp == NULL) |
| { |
| retval = ENOMEM; |
| goto out; |
| } |
| } |
| aliases_len = memcpy (tmp, aliases_len, |
| serv_resp.s_aliases_cnt |
| * sizeof (uint32_t)); |
| } |
| #endif |
| } |
| } |
| |
| if (s_name == NULL) |
| { |
| sock = __nscd_open_socket (key, keylen, type, &serv_resp, |
| sizeof (serv_resp)); |
| if (sock == -1) |
| { |
| __nss_not_use_nscd_services = 1; |
| goto out; |
| } |
| } |
| |
| /* No value found so far. */ |
| *result = NULL; |
| |
| if (__glibc_unlikely (serv_resp.found == -1)) |
| { |
| /* The daemon does not cache this database. */ |
| __nss_not_use_nscd_services = 1; |
| goto out_close; |
| } |
| |
| if (serv_resp.found == 1) |
| { |
| char *cp = buf; |
| uintptr_t align1; |
| uintptr_t align2; |
| size_t total_len; |
| ssize_t cnt; |
| int n; |
| |
| /* A first check whether the buffer is sufficiently large is possible. */ |
| /* Now allocate the buffer the array for the group members. We must |
| align the pointer and the base of the h_addr_list pointers. */ |
| align1 = ((__alignof__ (char *) - (cp - ((char *) 0))) |
| & (__alignof__ (char *) - 1)); |
| align2 = ((__alignof__ (char *) - ((cp + align1 + serv_resp.s_name_len |
| + serv_resp.s_proto_len) |
| - ((char *) 0))) |
| & (__alignof__ (char *) - 1)); |
| if (buflen < (align1 + serv_resp.s_name_len + serv_resp.s_proto_len |
| + align2 |
| + (serv_resp.s_aliases_cnt + 1) * sizeof (char *))) |
| { |
| no_room: |
| __set_errno (ERANGE); |
| retval = ERANGE; |
| goto out_close; |
| } |
| cp += align1; |
| |
| /* Prepare the result as far as we can. */ |
| resultbuf->s_aliases = (char **) cp; |
| cp += (serv_resp.s_aliases_cnt + 1) * sizeof (char *); |
| |
| resultbuf->s_name = cp; |
| cp += serv_resp.s_name_len; |
| resultbuf->s_proto = cp; |
| cp += serv_resp.s_proto_len + align2; |
| resultbuf->s_port = serv_resp.s_port; |
| |
| if (s_name == NULL) |
| { |
| struct iovec vec[2]; |
| |
| vec[0].iov_base = resultbuf->s_name; |
| vec[0].iov_len = serv_resp.s_name_len + serv_resp.s_proto_len; |
| total_len = vec[0].iov_len; |
| n = 1; |
| |
| if (serv_resp.s_aliases_cnt > 0) |
| { |
| assert (alloca_aliases_len == 0); |
| alloca_aliases_len |
| = __libc_use_alloca (alloca_used |
| + (serv_resp.s_aliases_cnt |
| * sizeof (uint32_t))); |
| if (alloca_aliases_len) |
| aliases_len = alloca_account (serv_resp.s_aliases_cnt |
| * sizeof (uint32_t), |
| alloca_used); |
| else |
| { |
| aliases_len = malloc (serv_resp.s_aliases_cnt |
| * sizeof (uint32_t)); |
| if (aliases_len == NULL) |
| { |
| retval = ENOMEM; |
| goto out_close; |
| } |
| } |
| vec[n].iov_base = (void *) aliases_len; |
| vec[n].iov_len = serv_resp.s_aliases_cnt * sizeof (uint32_t); |
| |
| total_len += serv_resp.s_aliases_cnt * sizeof (uint32_t); |
| ++n; |
| } |
| |
| if ((size_t) __readvall (sock, vec, n) != total_len) |
| goto out_close; |
| } |
| else |
| memcpy (resultbuf->s_name, s_name, |
| serv_resp.s_name_len + serv_resp.s_proto_len); |
| |
| /* Now we also can read the aliases. */ |
| total_len = 0; |
| for (cnt = 0; cnt < serv_resp.s_aliases_cnt; ++cnt) |
| { |
| resultbuf->s_aliases[cnt] = cp; |
| cp += aliases_len[cnt]; |
| total_len += aliases_len[cnt]; |
| } |
| resultbuf->s_aliases[cnt] = NULL; |
| |
| if (__builtin_expect ((const char *) aliases_list + total_len > recend, |
| 0)) |
| { |
| /* aliases_len array might contain garbage during nscd GC cycle, |
| retry rather than fail in that case. */ |
| if (aliases_list != NULL && mapped->head->gc_cycle != gc_cycle) |
| retval = -2; |
| goto out_close; |
| } |
| |
| /* See whether this would exceed the buffer capacity. */ |
| if (__glibc_unlikely (cp > buf + buflen)) |
| { |
| /* aliases_len array might contain garbage during nscd GC cycle, |
| retry rather than fail in that case. */ |
| if (aliases_list != NULL && mapped->head->gc_cycle != gc_cycle) |
| { |
| retval = -2; |
| goto out_close; |
| } |
| goto no_room; |
| } |
| |
| /* And finally read the aliases. */ |
| if (aliases_list == NULL) |
| { |
| if (total_len == 0 |
| || ((size_t) __readall (sock, resultbuf->s_aliases[0], total_len) |
| == total_len)) |
| { |
| retval = 0; |
| *result = resultbuf; |
| } |
| } |
| else |
| { |
| memcpy (resultbuf->s_aliases[0], aliases_list, total_len); |
| |
| /* Try to detect corrupt databases. */ |
| if (resultbuf->s_name[serv_resp.s_name_len - 1] != '\0' |
| || resultbuf->s_proto[serv_resp.s_proto_len - 1] != '\0' |
| || ({for (cnt = 0; cnt < serv_resp.s_aliases_cnt; ++cnt) |
| if (resultbuf->s_aliases[cnt][aliases_len[cnt] - 1] |
| != '\0') |
| break; |
| cnt < serv_resp.s_aliases_cnt; })) |
| { |
| /* We cannot use the database. */ |
| if (mapped->head->gc_cycle != gc_cycle) |
| retval = -2; |
| goto out_close; |
| } |
| |
| retval = 0; |
| *result = resultbuf; |
| } |
| } |
| else |
| { |
| /* Set errno to 0 to indicate no error, just no found record. */ |
| __set_errno (0); |
| /* Even though we have not found anything, the result is zero. */ |
| retval = 0; |
| } |
| |
| out_close: |
| if (sock != -1) |
| __close_nocancel_nostatus (sock); |
| out: |
| if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0) |
| { |
| /* When we come here this means there has been a GC cycle while we |
| were looking for the data. This means the data might have been |
| inconsistent. Retry if possible. */ |
| if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1) |
| { |
| /* nscd is just running gc now. Disable using the mapping. */ |
| if (atomic_decrement_val (&mapped->counter) == 0) |
| __nscd_unmap (mapped); |
| mapped = NO_MAPPING; |
| } |
| |
| if (retval != -1) |
| { |
| if (!alloca_aliases_len) |
| free ((void *) aliases_len); |
| goto retry; |
| } |
| } |
| |
| if (!alloca_aliases_len) |
| free ((void *) aliases_len); |
| if (!alloca_key) |
| free (key); |
| |
| return retval; |
| } |