diff options
Diffstat (limited to 'nscd/nscd_helper.c')
| -rw-r--r-- | nscd/nscd_helper.c | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/nscd/nscd_helper.c b/nscd/nscd_helper.c index 780878d1bb..5f3d54efcf 100644 --- a/nscd/nscd_helper.c +++ b/nscd/nscd_helper.c @@ -238,16 +238,19 @@ get_mapping (request_type type, const char *key, /* Room for the data sent along with the file descriptor. We expect the key name back. */ - struct iovec iov[1]; + uint64_t mapsize; + struct iovec iov[2]; iov[0].iov_base = resdata; iov[0].iov_len = keylen; + iov[1].iov_base = &mapsize; + iov[1].iov_len = sizeof (mapsize); union { struct cmsghdr hdr; char bytes[CMSG_SPACE (sizeof (int))]; } buf; - struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 1, + struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 2, .msg_control = buf.bytes, .msg_controllen = sizeof (buf) }; struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg); @@ -268,10 +271,7 @@ get_mapping (request_type type, const char *key, # ifndef MSG_CMSG_CLOEXEC # define MSG_CMSG_CLOEXEC 0 # endif - if (__builtin_expect (TEMP_FAILURE_RETRY (__recvmsg (sock, &msg, - MSG_CMSG_CLOEXEC)) - != keylen, 0)) - goto out_close2; + ssize_t n = TEMP_FAILURE_RETRY (__recvmsg (sock, &msg, MSG_CMSG_CLOEXEC)); if (__builtin_expect (CMSG_FIRSTHDR (&msg) == NULL || (CMSG_FIRSTHDR (&msg)->cmsg_len @@ -280,14 +280,25 @@ get_mapping (request_type type, const char *key, mapfd = *(int *) CMSG_DATA (cmsg); - struct stat64 st; - if (__builtin_expect (strcmp (resdata, key) != 0, 0) - || __builtin_expect (fstat64 (mapfd, &st) != 0, 0) - || __builtin_expect (st.st_size < sizeof (struct database_pers_head), 0)) + if (__builtin_expect (n != keylen && n != keylen + sizeof (mapsize), 0)) + goto out_close; + + if (__builtin_expect (strcmp (resdata, key) != 0, 0)) goto out_close; + if (__builtin_expect (n == keylen, 0)) + { + struct stat64 st; + if (__builtin_expect (fstat64 (mapfd, &st) != 0, 0) + || __builtin_expect (st.st_size < sizeof (struct database_pers_head), + 0)) + goto out_close; + + mapsize = st.st_size; + } + /* The file is large enough, map it now. */ - void *mapping = __mmap (NULL, st.st_size, PROT_READ, MAP_SHARED, mapfd, 0); + void *mapping = __mmap (NULL, mapsize, PROT_READ, MAP_SHARED, mapfd, 0); if (__builtin_expect (mapping != MAP_FAILED, 1)) { /* Check whether the database is correct and up-to-date. */ @@ -302,7 +313,7 @@ get_mapping (request_type type, const char *key, < time (NULL)), 0)) { out_unmap: - __munmap (mapping, st.st_size); + __munmap (mapping, mapsize); goto out_close; } @@ -310,7 +321,7 @@ get_mapping (request_type type, const char *key, ALIGN) + head->data_size); - if (__builtin_expect (st.st_size < size, 0)) + if (__builtin_expect (mapsize < size, 0)) goto out_unmap; /* Allocate a record for the mapping. */ |