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Merge branch '180-fix-cmsgbuf-usage' into 'master'

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Resolve "Intermittent recursive resolver issues [socket.c:2135]"

Closes #180

See merge request isc-projects/bind9!409
This commit is contained in:
Witold Krecicki 2018-06-26 11:55:14 -04:00
commit d0314a14fa
2 changed files with 57 additions and 101 deletions
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3
CHANGES
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@ -1,3 +1,6 @@
4980. [bug] Fix race in cmsg buffer usage in socket code.
[GL #180]
4979. [bug] Named-checkconf failed to detect bad in-view targets.
[GL #288]

155
lib/isc/unix/socket.c
View File

@ -319,6 +319,35 @@ typedef isc_event_t intev_t;
#define RCVBUFSIZE (32*1024)
#endif /* TUNE_LARGE */
/*%
* Instead of calculating the cmsgbuf lengths every time we take
* a rule of thumb approach - sizes are taken from x86_64 linux,
* multiplied by 2, everything should fit. Those sizes are not
* large enough to cause any concern.
*/
#if defined(USE_CMSG) && defined(ISC_PLATFORM_HAVEIN6PKTINFO)
#define CMSG_SP_IN6PKT 40
#else
#define CMSG_SP_IN6PKT 0
#endif
#if defined(USE_CMSG) && defined(SO_TIMESTAMP)
#define CMSG_SP_TIMESTAMP 32
#else
#define CMSG_SP_TIMESTAMP 0
#endif
#if defined(USE_CMSG) && (defined(IPV6_TCLASS) || defined(IP_TOS))
#define CMSG_SP_TCTOS 24
#else
#define CMSG_SP_TCTOS 0
#endif
#define CMSG_SP_INT 24
#define RECVCMSGBUFLEN (2*(CMSG_SP_IN6PKT + CMSG_SP_TIMESTAMP + CMSG_SP_TCTOS)+1)
#define SENDCMSGBUFLEN (2*(CMSG_SP_IN6PKT + CMSG_SP_INT + CMSG_SP_TCTOS)+1)
/*%
* The number of times a send operation is repeated if the result is EINTR.
*/
@ -375,11 +404,6 @@ struct isc__socket {
unsigned char overflow; /* used for MSG_TRUNC fake */
#endif
char *recvcmsgbuf;
ISC_SOCKADDR_LEN_T recvcmsgbuflen;
char *sendcmsgbuf;
ISC_SOCKADDR_LEN_T sendcmsgbuflen;
void *fdwatcharg;
isc_sockfdwatch_t fdwatchcb;
int fdwatchflags;
@ -487,9 +511,9 @@ static void internal_send(isc_task_t *, isc_event_t *);
static void internal_fdwatch_write(isc_task_t *, isc_event_t *);
static void internal_fdwatch_read(isc_task_t *, isc_event_t *);
static void process_cmsg(isc__socket_t *, struct msghdr *, isc_socketevent_t *);
static void build_msghdr_send(isc__socket_t *, isc_socketevent_t *,
static void build_msghdr_send(isc__socket_t *, char *, isc_socketevent_t *,
struct msghdr *, struct iovec *, size_t *);
static void build_msghdr_recv(isc__socket_t *, isc_socketevent_t *,
static void build_msghdr_recv(isc__socket_t *, char *, isc_socketevent_t *,
struct msghdr *, struct iovec *, size_t *);
#ifdef USE_WATCHER_THREAD
static isc_boolean_t process_ctlfd(isc__socketmgr_t *manager);
@ -1443,7 +1467,7 @@ process_cmsg(isc__socket_t *sock, struct msghdr *msg, isc_socketevent_t *dev) {
* this transaction can send.
*/
static void
build_msghdr_send(isc__socket_t *sock, isc_socketevent_t *dev,
build_msghdr_send(isc__socket_t *sock, char* cmsgbuf, isc_socketevent_t *dev,
struct msghdr *msg, struct iovec *iov, size_t *write_countp)
{
unsigned int iovcount;
@ -1456,9 +1480,6 @@ build_msghdr_send(isc__socket_t *sock, isc_socketevent_t *dev,
#endif
memset(msg, 0, sizeof(*msg));
if (sock->sendcmsgbuflen != 0U) {
memset(sock->sendcmsgbuf, 0, sock->sendcmsgbuflen);
}
if (!sock->connected) {
msg->msg_name = (void *)&dev->address.type.sa;
@ -1536,11 +1557,11 @@ build_msghdr_send(isc__socket_t *sock, isc_socketevent_t *dev,
"sendto pktinfo data, ifindex %u",
dev->pktinfo.ipi6_ifindex);
msg->msg_control = (void *)sock->sendcmsgbuf;
msg->msg_control = (void *)cmsgbuf;
msg->msg_controllen = cmsg_space(sizeof(struct in6_pktinfo));
INSIST(msg->msg_controllen <= sock->sendcmsgbuflen);
INSIST(msg->msg_controllen <= SENDCMSGBUFLEN);
cmsgp = (struct cmsghdr *)sock->sendcmsgbuf;
cmsgp = (struct cmsghdr *)cmsgbuf;
cmsgp->cmsg_level = IPPROTO_IPV6;
cmsgp->cmsg_type = IPV6_PKTINFO;
cmsgp->cmsg_len = cmsg_len(sizeof(struct in6_pktinfo));
@ -1555,11 +1576,11 @@ build_msghdr_send(isc__socket_t *sock, isc_socketevent_t *dev,
{
int use_min_mtu = 1; /* -1, 0, 1 */
cmsgp = (struct cmsghdr *)(sock->sendcmsgbuf +
cmsgp = (struct cmsghdr *)(cmsgbuf +
msg->msg_controllen);
msg->msg_control = (void *)sock->sendcmsgbuf;
msg->msg_control = (void *)cmsgbuf;
msg->msg_controllen += cmsg_space(sizeof(use_min_mtu));
INSIST(msg->msg_controllen <= sock->sendcmsgbuflen);
INSIST(msg->msg_controllen <= SENDCMSGBUFLEN);
cmsgp->cmsg_level = IPPROTO_IPV6;
cmsgp->cmsg_type = IPV6_USE_MIN_MTU;
@ -1585,11 +1606,11 @@ build_msghdr_send(isc__socket_t *sock, isc_socketevent_t *dev,
#ifdef IP_TOS
if (sock->pf == AF_INET && sock->pktdscp) {
cmsgp = (struct cmsghdr *)(sock->sendcmsgbuf +
cmsgp = (struct cmsghdr *)(cmsgbuf +
msg->msg_controllen);
msg->msg_control = (void *)sock->sendcmsgbuf;
msg->msg_control = (void *)cmsgbuf;
msg->msg_controllen += cmsg_space(sizeof(dscp));
INSIST(msg->msg_controllen <= sock->sendcmsgbuflen);
INSIST(msg->msg_controllen <= SENDCMSGBUFLEN);
cmsgp->cmsg_level = IPPROTO_IP;
cmsgp->cmsg_type = IP_TOS;
@ -1616,11 +1637,11 @@ build_msghdr_send(isc__socket_t *sock, isc_socketevent_t *dev,
#endif
#if defined(IPPROTO_IPV6) && defined(IPV6_TCLASS)
if (sock->pf == AF_INET6 && sock->pktdscp) {
cmsgp = (struct cmsghdr *)(sock->sendcmsgbuf +
cmsgp = (struct cmsghdr *)(cmsgbuf +
msg->msg_controllen);
msg->msg_control = (void *)sock->sendcmsgbuf;
msg->msg_control = (void *)cmsgbuf;
msg->msg_controllen += cmsg_space(sizeof(dscp));
INSIST(msg->msg_controllen <= sock->sendcmsgbuflen);
INSIST(msg->msg_controllen <= SENDCMSGBUFLEN);
cmsgp->cmsg_level = IPPROTO_IPV6;
cmsgp->cmsg_type = IPV6_TCLASS;
@ -1645,10 +1666,10 @@ build_msghdr_send(isc__socket_t *sock, isc_socketevent_t *dev,
}
#endif
if (msg->msg_controllen != 0 &&
msg->msg_controllen < sock->sendcmsgbuflen)
msg->msg_controllen < SENDCMSGBUFLEN)
{
memset(sock->sendcmsgbuf + msg->msg_controllen, 0,
sock->sendcmsgbuflen - msg->msg_controllen);
memset(cmsgbuf + msg->msg_controllen, 0,
SENDCMSGBUFLEN - msg->msg_controllen);
}
}
#endif
@ -1675,7 +1696,7 @@ build_msghdr_send(isc__socket_t *sock, isc_socketevent_t *dev,
* this transaction can receive.
*/
static void
build_msghdr_recv(isc__socket_t *sock, isc_socketevent_t *dev,
build_msghdr_recv(isc__socket_t *sock, char *cmsgbuf, isc_socketevent_t *dev,
struct msghdr *msg, struct iovec *iov, size_t *read_countp)
{
unsigned int iovcount;
@ -1773,8 +1794,8 @@ build_msghdr_recv(isc__socket_t *sock, isc_socketevent_t *dev,
#ifdef ISC_NET_BSD44MSGHDR
#if defined(USE_CMSG)
msg->msg_control = sock->recvcmsgbuf;
msg->msg_controllen = sock->recvcmsgbuflen;
msg->msg_control = cmsgbuf;
msg->msg_controllen = RECVCMSGBUFLEN;
#else
msg->msg_control = NULL;
msg->msg_controllen = 0;
@ -1877,8 +1898,9 @@ doio_recv(isc__socket_t *sock, isc_socketevent_t *dev) {
isc_buffer_t *buffer;
int recv_errno;
char strbuf[ISC_STRERRORSIZE];
char cmsgbuf[RECVCMSGBUFLEN] = {0};
build_msghdr_recv(sock, dev, &msghdr, iov, &read_count);
build_msghdr_recv(sock, cmsgbuf, dev, &msghdr, iov, &read_count);
#if defined(ISC_SOCKET_DEBUG)
dump_msg(&msghdr);
@ -2072,8 +2094,9 @@ doio_send(isc__socket_t *sock, isc_socketevent_t *dev) {
int attempts = 0;
int send_errno;
char strbuf[ISC_STRERRORSIZE];
char cmsgbuf[SENDCMSGBUFLEN] = {0};
build_msghdr_send(sock, dev, &msghdr, iov, &write_count);
build_msghdr_send(sock, cmsgbuf, dev, &msghdr, iov, &write_count);
resend:
if (sock->type == isc_sockettype_udp &&
@ -2291,7 +2314,6 @@ allocate_socket(isc__socketmgr_t *manager, isc_sockettype_t type,
{
isc__socket_t *sock;
isc_result_t result;
ISC_SOCKADDR_LEN_T cmsgbuflen;
sock = isc_mem_get(manager->mctx, sizeof(*sock));
@ -2312,53 +2334,6 @@ allocate_socket(isc__socketmgr_t *manager, isc_sockettype_t type,
ISC_LINK_INIT(sock, link);
sock->recvcmsgbuf = NULL;
sock->sendcmsgbuf = NULL;
/*
* Set up cmsg buffers.
*/
cmsgbuflen = 0;
#if defined(USE_CMSG) && defined(ISC_PLATFORM_HAVEIN6PKTINFO)
cmsgbuflen += cmsg_space(sizeof(struct in6_pktinfo));
#endif
#if defined(USE_CMSG) && defined(SO_TIMESTAMP)
cmsgbuflen += cmsg_space(sizeof(struct timeval));
#endif
#if defined(USE_CMSG) && (defined(IPV6_TCLASS) || defined(IP_TOS))
cmsgbuflen += cmsg_space(sizeof(int));
#endif
sock->recvcmsgbuflen = cmsgbuflen;
if (sock->recvcmsgbuflen != 0U) {
sock->recvcmsgbuf = isc_mem_get(manager->mctx, cmsgbuflen);
if (sock->recvcmsgbuf == NULL) {
result = ISC_R_NOMEMORY;
goto error;
}
}
cmsgbuflen = 0;
#if defined(USE_CMSG) && defined(ISC_PLATFORM_HAVEIN6PKTINFO)
cmsgbuflen += cmsg_space(sizeof(struct in6_pktinfo));
#if defined(IPV6_USE_MIN_MTU)
/*
* Provide space for working around FreeBSD's broken IPV6_USE_MIN_MTU
* support.
*/
cmsgbuflen += cmsg_space(sizeof(int));
#endif
#endif
#if defined(USE_CMSG) && (defined(IP_TOS) || defined(IPV6_TCLASS))
cmsgbuflen += cmsg_space(sizeof(int));
#endif
sock->sendcmsgbuflen = cmsgbuflen;
if (sock->sendcmsgbuflen != 0U) {
sock->sendcmsgbuf = isc_mem_get(manager->mctx, cmsgbuflen);
if (sock->sendcmsgbuf == NULL) {
result = ISC_R_NOMEMORY;
goto error;
}
}
memset(sock->name, 0, sizeof(sock->name));
sock->tag = NULL;
@ -2406,12 +2381,6 @@ allocate_socket(isc__socketmgr_t *manager, isc_sockettype_t type,
return (ISC_R_SUCCESS);
error:
if (sock->recvcmsgbuf != NULL)
isc_mem_put(manager->mctx, sock->recvcmsgbuf,
sock->recvcmsgbuflen);
if (sock->sendcmsgbuf != NULL)
isc_mem_put(manager->mctx, sock->sendcmsgbuf,
sock->sendcmsgbuflen);
isc_mem_put(manager->mctx, sock, sizeof(*sock));
return (result);
@ -2440,13 +2409,6 @@ free_socket(isc__socket_t **socketp) {
INSIST(ISC_LIST_EMPTY(sock->connect_list));
INSIST(!ISC_LINK_LINKED(sock, link));
if (sock->recvcmsgbuf != NULL)
isc_mem_put(sock->manager->mctx, sock->recvcmsgbuf,
sock->recvcmsgbuflen);
if (sock->sendcmsgbuf != NULL)
isc_mem_put(sock->manager->mctx, sock->sendcmsgbuf,
sock->sendcmsgbuflen);
sock->common.magic = 0;
sock->common.impmagic = 0;
@ -2817,15 +2779,6 @@ opensocket(isc__socketmgr_t *manager, isc__socket_t *sock,
#endif /* SO_TIMESTAMP */
#if defined(ISC_PLATFORM_HAVEIPV6)
if (sock->pf == AF_INET6 && sock->recvcmsgbuflen == 0U) {
/*
* Warn explicitly because this anomaly can be hidden
* in usual operation (and unexpectedly appear later).
*/
UNEXPECTED_ERROR(__FILE__, __LINE__,
"No buffer available to receive "
"IPv6 destination");
}
#ifdef ISC_PLATFORM_HAVEIN6PKTINFO
#ifdef IPV6_RECVPKTINFO
/* RFC 3542 */