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| author | Laurent Bercot <ska-skaware@skarnet.org> | 2017-04-23 00:00:10 +0000 |
|---|---|---|
| committer | Laurent Bercot <ska-skaware@skarnet.org> | 2017-04-23 00:00:10 +0000 |
| commit | b2eac2dedd62224df07148a9e42eae0197902c00 (patch) | |
| tree | 7f78a7260c9b26f386da7cf177cc8a9034bade36 /src/libunixonacid | |
| parent | e48c16f37bac55820c605f82c07f04436a55f415 (diff) | |
| download | skalibs-b2eac2dedd62224df07148a9e42eae0197902c00.tar.xz | |
Align ancillary buffers on struct cmsghdr and int boundaries
Diffstat (limited to 'src/libunixonacid')
| -rw-r--r-- | src/libunixonacid/unixmessage_receive.c | 10 | ||||
| -rw-r--r-- | src/libunixonacid/unixmessage_sender_flush.c | 13 |
2 files changed, 18 insertions, 5 deletions
diff --git a/src/libunixonacid/unixmessage_receive.c b/src/libunixonacid/unixmessage_receive.c index 9672b63..8ca8c0b 100644 --- a/src/libunixonacid/unixmessage_receive.c +++ b/src/libunixonacid/unixmessage_receive.c @@ -14,6 +14,12 @@ #include <skalibs/stralloc.h> #include <skalibs/unixmessage.h> +union aligner_u +{ + struct cmsghdr cmsghdr ; + int i ; +} ; + static int const awesomeflags = #ifdef SKALIBS_HASMSGDONTWAIT MSG_DONTWAIT @@ -36,7 +42,7 @@ static int const awesomeflags = static int unixmessage_receiver_fill (unixmessage_receiver_t *b) { - char ancilbuf[CMSG_SPACE(b->auxb.a - 1)] ; + union aligner_u ancilbuf[1 + CMSG_SPACE(b->auxb.a - 1) / sizeof(union aligner_u)] ; struct iovec iov[2] ; struct msghdr msghdr = { @@ -46,7 +52,7 @@ static int unixmessage_receiver_fill (unixmessage_receiver_t *b) .msg_iovlen = 2, .msg_flags = 0, .msg_control = b->fds_ok & 1 ? ancilbuf : 0, - .msg_controllen = b->fds_ok & 1 ? sizeof(ancilbuf) : 0 + .msg_controllen = b->fds_ok & 1 ? CMSG_SPACE(b->auxb.a - 1) : 0 } ; ssize_t r = -1 ; if (cbuffer_isfull(&b->mainb) || ((b->fds_ok & 1) && cbuffer_isfull(&b->auxb))) diff --git a/src/libunixonacid/unixmessage_sender_flush.c b/src/libunixonacid/unixmessage_sender_flush.c index e7d4299..eb2645c 100644 --- a/src/libunixonacid/unixmessage_sender_flush.c +++ b/src/libunixonacid/unixmessage_sender_flush.c @@ -21,6 +21,13 @@ #define MSG_NOSIGNAL 0 #endif +union aligner_u +{ + struct cmsghdr cmsghdr ; + int i ; +} ; + + /* XXX: sendmsg/recvmsg is badly, badly specified. XXX: We assume ancillary data is attached to the first byte. @@ -68,7 +75,7 @@ int unixmessage_sender_flush (unixmessage_sender_t *b) { .iov_base = pack, .iov_len = 6 }, { .iov_base = b->data.s + offsets[b->head].left, .iov_len = len } } ; - char ancilbuf[CMSG_SPACE(nfds * sizeof(int))] ; + union aligner_u ancilbuf[1 + CMSG_SPACE(nfds * sizeof(int)) / sizeof(union aligner_u)] ; struct msghdr hdr = { .msg_name = 0, @@ -76,7 +83,7 @@ int unixmessage_sender_flush (unixmessage_sender_t *b) .msg_iov = v, .msg_iovlen = 2, .msg_control = nfds ? ancilbuf : 0, - .msg_controllen = nfds ? sizeof(ancilbuf) : 0 + .msg_controllen = nfds ? CMSG_SPACE(nfds * sizeof(int)) : 0 } ; uint32_pack_big(pack, (uint32_t)len) ; uint16_pack_big(pack + 4, (uint16_t)nfds) ; @@ -84,7 +91,7 @@ int unixmessage_sender_flush (unixmessage_sender_t *b) { struct cmsghdr *cp = CMSG_FIRSTHDR(&hdr) ; size_t i = 0 ; - memset(ancilbuf, 0, sizeof(ancilbuf)) ; + memset(hdr.msg_control, 0, hdr.msg_controllen) ; cp->cmsg_level = SOL_SOCKET ; cp->cmsg_type = SCM_RIGHTS ; cp->cmsg_len = CMSG_LEN(nfds * sizeof(int)) ; |