diff options
Diffstat (limited to 'nscd/nscd_getgr_r.c')
| -rw-r--r-- | nscd/nscd_getgr_r.c | 154 |
1 files changed, 114 insertions, 40 deletions
diff --git a/nscd/nscd_getgr_r.c b/nscd/nscd_getgr_r.c index b9cde73044..3a66bb849b 100644 --- a/nscd/nscd_getgr_r.c +++ b/nscd/nscd_getgr_r.c @@ -18,6 +18,7 @@ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ +#include <assert.h> #include <errno.h> #include <grp.h> #include <stdint.h> @@ -25,6 +26,7 @@ #include <stdlib.h> #include <string.h> #include <unistd.h> +#include <sys/mman.h> #include <sys/socket.h> #include <sys/uio.h> #include <sys/un.h> @@ -64,36 +66,82 @@ __nscd_getgrgid_r (gid_t gid, struct group *resultbuf, char *buffer, } +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) +{ + + if (map_handle.mapped != NO_MAPPING) + free (map_handle.mapped); +} + + static int internal_function nscd_getgr_r (const char *key, size_t keylen, request_type type, struct group *resultbuf, char *buffer, size_t buflen, struct group **result) { - gr_response_header gr_resp; - int sock = __nscd_open_socket (key, keylen, type, &gr_resp, - sizeof (gr_resp)); - if (sock == -1) + const gr_response_header *gr_resp = NULL; + const uint32_t *len = NULL; + const char *gr_name = NULL; + size_t gr_name_len = 0; + int retval = -1; + int gc_cycle; + const char *recend = (const char *) ~UINTMAX_C (0); + + /* If the mapping is available, try to search there instead of + communicating with the nscd. */ + struct mapped_database *mapped = __nscd_get_map_ref (GETFDGR, "group", + &map_handle, &gc_cycle); + retry: + if (mapped != NO_MAPPING) { - __nss_not_use_nscd_group = 1; - return -1; + const struct datahead *found = __nscd_cache_search (type, key, keylen, + mapped); + if (found != NULL) + { + gr_resp = &found->data[0].grdata; + len = (const uint32_t *) (gr_resp + 1); + /* The alignment is always sufficient. */ + assert (((uintptr_t) len & (__alignof__ (*len) - 1)) == 0); + gr_name = ((const char *) len + + gr_resp->gr_mem_cnt * sizeof (uint32_t)); + gr_name_len = gr_resp->gr_name_len + gr_resp->gr_passwd_len; + recend = (const char *) found->data + found->recsize; + } + } + + gr_response_header gr_resp_mem; + int sock = -1; + if (gr_resp == NULL) + { + sock = __nscd_open_socket (key, keylen, type, &gr_resp_mem, + sizeof (gr_resp_mem)); + if (sock == -1) + { + __nss_not_use_nscd_group = 1; + goto out; + } + + gr_resp = &gr_resp_mem; } /* No value found so far. */ - int retval = -1; *result = NULL; - if (gr_resp.found == -1) + if (__builtin_expect (gr_resp->found == -1, 0)) { /* The daemon does not cache this database. */ __nss_not_use_nscd_group = 1; - goto out; + goto out_close; } - if (gr_resp.found == 1) + if (gr_resp->found == 1) { struct iovec vec[2]; - uint32_t *len; char *p = buffer; size_t total_len; uintptr_t align; @@ -103,71 +151,90 @@ nscd_getgr_r (const char *key, size_t keylen, request_type type, align the pointer. */ align = ((__alignof__ (char *) - (p - ((char *) 0))) & (__alignof__ (char *) - 1)); - total_len = align + (1 + gr_resp.gr_mem_cnt) * sizeof (char *) - + gr_resp.gr_name_len + gr_resp.gr_passwd_len; + total_len = (align + (1 + gr_resp->gr_mem_cnt) * sizeof (char *) + + gr_resp->gr_name_len + gr_resp->gr_passwd_len); if (__builtin_expect (buflen < total_len, 0)) { no_room: __set_errno (ERANGE); retval = ERANGE; - goto out; + goto out_close; } buflen -= total_len; p += align; resultbuf->gr_mem = (char **) p; - p += (1 + gr_resp.gr_mem_cnt) * sizeof (char *); + p += (1 + gr_resp->gr_mem_cnt) * sizeof (char *); /* Set pointers for strings. */ resultbuf->gr_name = p; - p += gr_resp.gr_name_len; + p += gr_resp->gr_name_len; resultbuf->gr_passwd = p; - p += gr_resp.gr_passwd_len; + p += gr_resp->gr_passwd_len; /* Fill in what we know now. */ - resultbuf->gr_gid = gr_resp.gr_gid; + resultbuf->gr_gid = gr_resp->gr_gid; - /* Allocate array to store lengths. */ - len = (uint32_t *) alloca (gr_resp.gr_mem_cnt * sizeof (uint32_t)); + /* Read the length information, group name, and password. */ + if (len == NULL) + { + /* Allocate array to store lengths. */ + len = (uint32_t *) alloca (gr_resp->gr_mem_cnt * sizeof (uint32_t)); - total_len = gr_resp.gr_mem_cnt * sizeof (uint32_t); - vec[0].iov_base = len; - vec[0].iov_len = total_len; - vec[1].iov_base = resultbuf->gr_name; - vec[1].iov_len = gr_resp.gr_name_len + gr_resp.gr_passwd_len; - total_len += gr_resp.gr_name_len + gr_resp.gr_passwd_len; + vec[0].iov_base = (void *) len; + vec[0].iov_len = gr_resp->gr_mem_cnt * sizeof (uint32_t); + vec[1].iov_base = resultbuf->gr_name; + vec[1].iov_len = gr_resp->gr_name_len + gr_resp->gr_passwd_len; + total_len = vec[0].iov_len + vec[1].iov_len; - /* Get this data. */ - size_t n = TEMP_FAILURE_RETRY (__readv (sock, vec, 2)); - if (__builtin_expect (n != total_len, 0)) - goto out; + /* Get this data. */ + size_t n = TEMP_FAILURE_RETRY (__readv (sock, vec, 2)); + if (__builtin_expect (n != total_len, 0)) + goto out_close; + } + else + /* We already have the data. Just copy the group name and + password. */ + memcpy (resultbuf->gr_name, gr_name, gr_name_len); /* Clear the terminating entry. */ - resultbuf->gr_mem[gr_resp.gr_mem_cnt] = NULL; + resultbuf->gr_mem[gr_resp->gr_mem_cnt] = NULL; /* Prepare reading the group members. */ total_len = 0; - for (cnt = 0; cnt < gr_resp.gr_mem_cnt; ++cnt) + for (cnt = 0; cnt < gr_resp->gr_mem_cnt; ++cnt) { resultbuf->gr_mem[cnt] = p; total_len += len[cnt]; p += len[cnt]; } + if (__builtin_expect (gr_name + gr_name_len + total_len > recend, 0)) + goto out_close; if (__builtin_expect (total_len > buflen, 0)) goto no_room; retval = 0; - n = TEMP_FAILURE_RETRY (__read (sock, resultbuf->gr_mem[0], - total_len)); - if (__builtin_expect (n != total_len, 0)) + if (gr_name == NULL) { - /* The `errno' to some value != ERANGE. */ - __set_errno (ENOENT); - retval = ENOENT; + size_t n = TEMP_FAILURE_RETRY (__read (sock, resultbuf->gr_mem[0], + total_len)); + if (__builtin_expect (n != total_len, 0)) + { + /* The `errno' to some value != ERANGE. */ + __set_errno (ENOENT); + retval = ENOENT; + } + else + *result = resultbuf; } else - *result = resultbuf; + { + /* Copy the group member names. */ + memcpy (resultbuf->gr_mem[0], gr_name + gr_name_len, total_len); + + *result = resultbuf; + } } else { @@ -177,8 +244,15 @@ nscd_getgr_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_not_cancel_no_status (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; } |