diff options
Diffstat (limited to 'REORG.TODO/nscd/nscd_getserv_r.c')
| -rw-r--r-- | REORG.TODO/nscd/nscd_getserv_r.c | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/REORG.TODO/nscd/nscd_getserv_r.c b/REORG.TODO/nscd/nscd_getserv_r.c new file mode 100644 index 0000000000..7dfb1c828d --- /dev/null +++ b/REORG.TODO/nscd/nscd_getserv_r.c @@ -0,0 +1,388 @@ +/* Copyright (C) 2007-2017 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_not_cancel_no_status (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; +} |