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Code Issues Releases Wiki Activity

Use completely static-sized buffers

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This commit is contained in:
Witold Kręcicki
2018-06-26 15:11:28 +02:00
parent d79be7dd5e
commit 49f90025a0
1 changed files with 39 additions and 57 deletions
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96
lib/isc/unix/socket.c
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@@ -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.
*/
@@ -375,9 +404,6 @@ struct isc__socket {
unsigned char overflow; /* used for MSG_TRUNC fake */
#endif
ISC_SOCKADDR_LEN_T recvcmsgbuflen;
ISC_SOCKADDR_LEN_T sendcmsgbuflen;
void *fdwatcharg;
isc_sockfdwatch_t fdwatchcb;
int fdwatchflags;
@@ -1455,10 +1481,6 @@ build_msghdr_send(isc__socket_t *sock, char* cmsgbuf, isc_socketevent_t *dev,
memset(msg, 0, sizeof(*msg));
if (sock->sendcmsgbuflen != 0U) {
memset(cmsgbuf, 0, sock->sendcmsgbuflen);
}
if (!sock->connected) {
msg->msg_name = (void *)&dev->address.type.sa;
msg->msg_namelen = dev->address.length;
@@ -1537,7 +1559,7 @@ build_msghdr_send(isc__socket_t *sock, char* cmsgbuf, isc_socketevent_t *dev,
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 *)cmsgbuf;
cmsgp->cmsg_level = IPPROTO_IPV6;
@@ -1556,9 +1578,9 @@ build_msghdr_send(isc__socket_t *sock, char* cmsgbuf, isc_socketevent_t *dev,
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;
@@ -1588,7 +1610,7 @@ build_msghdr_send(isc__socket_t *sock, char* cmsgbuf, isc_socketevent_t *dev,
msg->msg_controllen);
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;
@@ -1619,7 +1641,7 @@ build_msghdr_send(isc__socket_t *sock, char* cmsgbuf, isc_socketevent_t *dev,
msg->msg_controllen);
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;
@@ -1644,10 +1666,10 @@ build_msghdr_send(isc__socket_t *sock, char* cmsgbuf, isc_socketevent_t *dev,
}
#endif
if (msg->msg_controllen != 0 &&
msg->msg_controllen < sock->sendcmsgbuflen)
msg->msg_controllen < SENDCMSGBUFLEN)
{
memset(cmsgbuf + msg->msg_controllen, 0,
sock->sendcmsgbuflen - msg->msg_controllen);
SENDCMSGBUFLEN - msg->msg_controllen);
}
}
#endif
@@ -1773,7 +1795,7 @@ build_msghdr_recv(isc__socket_t *sock, char *cmsgbuf, isc_socketevent_t *dev,
#ifdef ISC_NET_BSD44MSGHDR
#if defined(USE_CMSG)
msg->msg_control = cmsgbuf;
msg->msg_controllen = sock->recvcmsgbuflen;
msg->msg_controllen = RECVCMSGBUFLEN;
#else
msg->msg_control = NULL;
msg->msg_controllen = 0;
@@ -1876,7 +1898,7 @@ doio_recv(isc__socket_t *sock, isc_socketevent_t *dev) {
isc_buffer_t *buffer;
int recv_errno;
char strbuf[ISC_STRERRORSIZE];
char cmsgbuf[sock->recvcmsgbuflen];
char cmsgbuf[RECVCMSGBUFLEN] = {0};
build_msghdr_recv(sock, cmsgbuf, dev, &msghdr, iov, &read_count);
@@ -2072,7 +2094,7 @@ doio_send(isc__socket_t *sock, isc_socketevent_t *dev) {
int attempts = 0;
int send_errno;
char strbuf[ISC_STRERRORSIZE];
char cmsgbuf[sock->sendcmsgbuflen];
char cmsgbuf[SENDCMSGBUFLEN] = {0};
build_msghdr_send(sock, cmsgbuf, dev, &msghdr, iov, &write_count);
@@ -2292,7 +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));
@@ -2313,36 +2334,6 @@ allocate_socket(isc__socketmgr_t *manager, isc_sockettype_t type,
ISC_LINK_INIT(sock, link);
/*
* Set up cmsg buffer lengths.
*/
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;
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;
memset(sock->name, 0, sizeof(sock->name));
sock->tag = NULL;
@@ -2788,15 +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 */