diff options
Diffstat (limited to 'nscd/nscd_gethst_r.c')
| -rw-r--r-- | nscd/nscd_gethst_r.c | 295 |
1 files changed, 174 insertions, 121 deletions
diff --git a/nscd/nscd_gethst_r.c b/nscd/nscd_gethst_r.c index 7449aade80..42327dd317 100644 --- a/nscd/nscd_gethst_r.c +++ b/nscd/nscd_gethst_r.c @@ -17,6 +17,7 @@ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ +#include <assert.h> #include <errno.h> #include <netdb.h> #include <resolv.h> @@ -26,9 +27,7 @@ #include <string.h> #include <unistd.h> #include <arpa/nameser.h> -#include <sys/socket.h> -#include <sys/uio.h> -#include <sys/un.h> +#include <sys/mman.h> #include <not-cancel.h> #include "nscd-client.h" @@ -89,56 +88,15 @@ __nscd_gethostbyaddr_r (const void *addr, socklen_t len, int type, } -/* Create a socket connected to a name. */ -int -__nscd_open_socket (const char *key, size_t keylen, request_type type, - void *response, size_t responselen) +libc_locked_map_ptr (map_handle); +/* 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 (gr_map_free) { - struct sockaddr_un addr; - int sock; - int saved_errno = errno; - - sock = __socket (PF_UNIX, SOCK_STREAM, 0); - if (sock < 0) - { - __set_errno (saved_errno); - return -1; - } - - addr.sun_family = AF_UNIX; - strcpy (addr.sun_path, _PATH_NSCDSOCKET); - if (__connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0) - { - __set_errno (saved_errno); - goto out; - } - - request_header req; - req.version = NSCD_VERSION; - req.type = type; - req.key_len = keylen; - - struct iovec vec[2]; - vec[0].iov_base = &req; - vec[0].iov_len = sizeof (request_header); - vec[1].iov_base = (void *) key; - vec[1].iov_len = keylen; - ssize_t nbytes = TEMP_FAILURE_RETRY (__writev (sock, vec, 2)); - if (nbytes != (ssize_t) (sizeof (request_header) + keylen)) - { - out: - close_not_cancel_no_status (sock); - sock = -1; - } - else - { - nbytes = TEMP_FAILURE_RETRY (__read (sock, response, responselen)); - if (nbytes != (ssize_t) responselen) - goto out; - } - - return sock; + if (map_handle.mapped != NO_MAPPING) + free (map_handle.mapped); } @@ -148,30 +106,89 @@ nscd_gethst_r (const char *key, size_t keylen, request_type type, struct hostent *resultbuf, char *buffer, size_t buflen, struct hostent **result, int *h_errnop) { - hst_response_header hst_resp; - int sock = __nscd_open_socket (key, keylen, type, &hst_resp, - sizeof (hst_resp)); - if (sock == -1) + const hst_response_header *hst_resp = NULL; + const char *h_name = NULL; + const uint32_t *aliases_len = NULL; + const char *addr_list = NULL; + size_t addr_list_len = 0; + int retval = -1; + int gc_cycle; + const char *recend = (const char *) ~UINTMAX_C (0); + int sock = -1; + + /* If the mapping is available, try to search there instead of + communicating with the nscd. */ + struct mapped_database *mapped = __nscd_get_map_ref (GETFDHST, "hosts", + &map_handle, &gc_cycle); + retry: + if (mapped != MAP_FAILED) { - __nss_not_use_nscd_hosts = 1; - return -1; + const struct datahead *found = __nscd_cache_search (type, key, keylen, + mapped); + if (found != NULL) + { + hst_resp = &found->data[0].hstdata; + h_name = (char *) (hst_resp + 1); + aliases_len = (uint32_t *) (h_name + hst_resp->h_name_len); + addr_list = ((char *) aliases_len + + hst_resp->h_aliases_cnt * sizeof (uint32_t)); + addr_list_len = hst_resp->h_addr_list_cnt * INADDRSZ; + +#ifndef _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 (hst_resp->h_aliases_cnt + * sizeof (uint32_t)); + aliases_len = memcpy (tmp, aliases_len, + hst_resp->h_aliases_cnt + * sizeof (uint32_t)); + } +#endif + if (type != GETHOSTBYADDR && type != GETHOSTBYNAME) + { + if (hst_resp->h_length == INADDRSZ) + addr_list += addr_list_len; + addr_list_len = hst_resp->h_addr_list_cnt * IN6ADDRSZ; + } + recend = (const char *) found->data + found->recsize; + if (__builtin_expect ((const char *) addr_list + addr_list_len + > recend, 0)) + goto out_close; + } + } + + hst_response_header hst_resp_mem; + if (hst_resp == NULL) + { + sock = __nscd_open_socket (key, keylen, type, &hst_resp_mem, + sizeof (hst_resp_mem)); + if (sock == -1) + { + __nss_not_use_nscd_hosts = 1; + goto out;; + } + + hst_resp = &hst_resp_mem; } /* No value found so far. */ - int retval = -1; *result = NULL; - if (hst_resp.found == -1) + if (__builtin_expect (hst_resp->found == -1, 0)) { /* The daemon does not cache this database. */ __nss_not_use_nscd_hosts = 1; - goto out; + goto out_close; } - if (hst_resp.found == 1) + if (hst_resp->found == 1) { struct iovec vec[4]; - uint32_t *aliases_len; char *cp = buffer; uintptr_t align1; uintptr_t align2; @@ -185,96 +202,110 @@ nscd_gethst_r (const char *key, size_t keylen, request_type type, 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 + hst_resp.h_name_len) + align2 = ((__alignof__ (char *) - ((cp + align1 + hst_resp->h_name_len) - ((char *) 0))) & (__alignof__ (char *) - 1)); - if (buflen < (align1 + hst_resp.h_name_len + align2 - + ((hst_resp.h_aliases_cnt + hst_resp.h_addr_list_cnt + 2) + if (buflen < (align1 + hst_resp->h_name_len + align2 + + ((hst_resp->h_aliases_cnt + hst_resp->h_addr_list_cnt + + 2) * sizeof (char *)) - + hst_resp.h_addr_list_cnt * (type == AF_INET - ? INADDRSZ : IN6ADDRSZ))) + + hst_resp->h_addr_list_cnt * (type == AF_INET + ? INADDRSZ : IN6ADDRSZ))) { no_room: __set_errno (ERANGE); retval = ERANGE; - goto out; + goto out_close; } cp += align1; /* Prepare the result as far as we can. */ resultbuf->h_aliases = (char **) cp; - cp += (hst_resp.h_aliases_cnt + 1) * sizeof (char *); + cp += (hst_resp->h_aliases_cnt + 1) * sizeof (char *); resultbuf->h_addr_list = (char **) cp; - cp += (hst_resp.h_addr_list_cnt + 1) * sizeof (char *); + cp += (hst_resp->h_addr_list_cnt + 1) * sizeof (char *); resultbuf->h_name = cp; - cp += hst_resp.h_name_len + align2; - vec[0].iov_base = resultbuf->h_name; - vec[0].iov_len = hst_resp.h_name_len; - - aliases_len = alloca (hst_resp.h_aliases_cnt * sizeof (uint32_t)); - vec[1].iov_base = aliases_len; - vec[1].iov_len = hst_resp.h_aliases_cnt * sizeof (uint32_t); + cp += hst_resp->h_name_len + align2; - total_len = (hst_resp.h_name_len - + hst_resp.h_aliases_cnt * sizeof (uint32_t)); - - n = 2; if (type == GETHOSTBYADDR || type == GETHOSTBYNAME) { - vec[2].iov_base = cp; - vec[2].iov_len = hst_resp.h_addr_list_cnt * INADDRSZ; - - for (cnt = 0; cnt < hst_resp.h_addr_list_cnt; ++cnt) - { - resultbuf->h_addr_list[cnt] = cp; - cp += INADDRSZ; - } - resultbuf->h_addrtype = AF_INET; resultbuf->h_length = INADDRSZ; - - total_len += hst_resp.h_addr_list_cnt * INADDRSZ; - - n = 3; } else { - if (hst_resp.h_length == INADDRSZ) - { - ignore = alloca (hst_resp.h_addr_list_cnt * INADDRSZ); - vec[2].iov_base = ignore; - vec[2].iov_len = hst_resp.h_addr_list_cnt * INADDRSZ; + resultbuf->h_addrtype = AF_INET6; + resultbuf->h_length = IN6ADDRSZ; + } + for (cnt = 0; cnt < hst_resp->h_addr_list_cnt; ++cnt) + { + resultbuf->h_addr_list[cnt] = cp; + cp += resultbuf->h_length; + } + resultbuf->h_addr_list[cnt] = NULL; - total_len += hst_resp.h_addr_list_cnt * INADDRSZ; + if (h_name == NULL) + { + vec[0].iov_base = resultbuf->h_name; + vec[0].iov_len = hst_resp->h_name_len; + total_len = hst_resp->h_name_len; + n = 1; - n = 3; - } + if (hst_resp->h_aliases_cnt > 0) + { + aliases_len = alloca (hst_resp->h_aliases_cnt + * sizeof (uint32_t)); + vec[n].iov_base = (void *) aliases_len; + vec[n].iov_len = hst_resp->h_aliases_cnt * sizeof (uint32_t); - vec[n].iov_base = cp; - vec[n].iov_len = hst_resp.h_addr_list_cnt * IN6ADDRSZ; + total_len += hst_resp->h_aliases_cnt * sizeof (uint32_t); + ++n; + } - for (cnt = 0; cnt < hst_resp.h_addr_list_cnt; ++cnt) + if (type == GETHOSTBYADDR || type == GETHOSTBYNAME) { - resultbuf->h_addr_list[cnt] = cp; - cp += IN6ADDRSZ; + vec[n].iov_base = resultbuf->h_addr_list[0]; + vec[n].iov_len = hst_resp->h_addr_list_cnt * INADDRSZ; + + total_len += hst_resp->h_addr_list_cnt * INADDRSZ; + + ++n; } + else + { + if (hst_resp->h_length == INADDRSZ) + { + ignore = alloca (hst_resp->h_addr_list_cnt * INADDRSZ); + vec[n].iov_base = ignore; + vec[n].iov_len = hst_resp->h_addr_list_cnt * INADDRSZ; - resultbuf->h_addrtype = AF_INET6; - resultbuf->h_length = IN6ADDRSZ; + total_len += hst_resp->h_addr_list_cnt * INADDRSZ; - total_len += hst_resp.h_addr_list_cnt * IN6ADDRSZ; + ++n; + } - ++n; - } - resultbuf->h_addr_list[cnt] = NULL; + vec[n].iov_base = resultbuf->h_addr_list[0]; + vec[n].iov_len = hst_resp->h_addr_list_cnt * IN6ADDRSZ; - if ((size_t) TEMP_FAILURE_RETRY (__readv (sock, vec, n)) != total_len) - goto out; + total_len += hst_resp->h_addr_list_cnt * IN6ADDRSZ; + + ++n; + } + + if ((size_t) TEMP_FAILURE_RETRY (__readv (sock, vec, n)) + != total_len) + goto out_close; + } + else + { + memcpy (resultbuf->h_name, h_name, hst_resp->h_name_len); + memcpy (resultbuf->h_addr_list[0], addr_list, addr_list_len); + } /* Now we also can read the aliases. */ total_len = 0; - for (cnt = 0; cnt < hst_resp.h_aliases_cnt; ++cnt) + for (cnt = 0; cnt < hst_resp->h_aliases_cnt; ++cnt) { resultbuf->h_aliases[cnt] = cp; cp += aliases_len[cnt]; @@ -282,14 +313,29 @@ nscd_gethst_r (const char *key, size_t keylen, request_type type, } resultbuf->h_aliases[cnt] = NULL; + if (__builtin_expect ((const char *) addr_list + addr_list_len + + total_len > recend, 0)) + goto out_close; /* See whether this would exceed the buffer capacity. */ - if (cp > buffer + buflen) + if (__builtin_expect (cp > buffer + buflen, 0)) goto no_room; /* And finally read the aliases. */ - if ((size_t) TEMP_FAILURE_RETRY (__read (sock, resultbuf->h_aliases[0], - total_len)) == total_len) + if (addr_list == NULL) + { + if ((size_t) TEMP_FAILURE_RETRY (__read (sock, + resultbuf->h_aliases[0], + total_len)) == total_len) + { + retval = 0; + *result = resultbuf; + } + } + else { + memcpy (resultbuf->h_aliases[0], + (const char *) addr_list + addr_list_len, total_len); + retval = 0; *result = resultbuf; } @@ -297,7 +343,7 @@ nscd_gethst_r (const char *key, size_t keylen, request_type type, else { /* Store the error number. */ - *h_errnop = hst_resp.error; + *h_errnop = hst_resp->error; /* The `errno' to some value != ERANGE. */ __set_errno (ENOENT); @@ -305,8 +351,15 @@ nscd_gethst_r (const char *key, size_t keylen, request_type type, retval = 0; } + out_close: + if (sock != -1) + close_not_cancel_no_status (sock); out: - __close (sock); + 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. */ + goto retry; return retval; } |