Allow ssfilter_bytecompile to return 0 for filter ops the kernel does not support. If such an op is in the filter string then all filtering is done in userspace.
Signed-off-by: David Ahern <d...@cumulusnetworks.com> --- misc/ss.c | 52 +++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 37 insertions(+), 15 deletions(-) diff --git a/misc/ss.c b/misc/ss.c index f164ca920308..0510701619ac 100644 --- a/misc/ss.c +++ b/misc/ss.c @@ -1273,11 +1273,16 @@ static int ssfilter_bytecompile(struct ssfilter *f, char **bytecode) case SSF_AND: { - char *a1, *a2, *a; + char *a1 = NULL, *a2 = NULL, *a; int l1, l2; l1 = ssfilter_bytecompile(f->pred, &a1); l2 = ssfilter_bytecompile(f->post, &a2); + if (!l1 || !l2) { + free(a1); + free(a2); + return 0; + } if (!(a = malloc(l1+l2))) abort(); memcpy(a, a1, l1); memcpy(a+l1, a2, l2); @@ -1288,11 +1293,16 @@ static int ssfilter_bytecompile(struct ssfilter *f, char **bytecode) } case SSF_OR: { - char *a1, *a2, *a; + char *a1 = NULL, *a2 = NULL, *a; int l1, l2; l1 = ssfilter_bytecompile(f->pred, &a1); l2 = ssfilter_bytecompile(f->post, &a2); + if (!l1 || !l2) { + free(a1); + free(a2); + return 0; + } if (!(a = malloc(l1+l2+4))) abort(); memcpy(a, a1, l1); memcpy(a+l1+4, a2, l2); @@ -1303,10 +1313,14 @@ static int ssfilter_bytecompile(struct ssfilter *f, char **bytecode) } case SSF_NOT: { - char *a1, *a; + char *a1 = NULL, *a; int l1; l1 = ssfilter_bytecompile(f->pred, &a1); + if (!l1) { + free(a1); + return 0; + } if (!(a = malloc(l1+4))) abort(); memcpy(a, a1, l1); free(a1); @@ -2127,6 +2141,7 @@ static int tcpdiag_send(int fd, int protocol, struct filter *f) struct msghdr msg; struct rtattr rta; struct iovec iov[3]; + int iovlen = 1; if (protocol == IPPROTO_UDP) return -1; @@ -2162,18 +2177,21 @@ static int tcpdiag_send(int fd, int protocol, struct filter *f) }; if (f->f) { bclen = ssfilter_bytecompile(f->f, &bc); - rta.rta_type = INET_DIAG_REQ_BYTECODE; - rta.rta_len = RTA_LENGTH(bclen); - iov[1] = (struct iovec){ &rta, sizeof(rta) }; - iov[2] = (struct iovec){ bc, bclen }; - req.nlh.nlmsg_len += RTA_LENGTH(bclen); + if (bclen) { + rta.rta_type = INET_DIAG_REQ_BYTECODE; + rta.rta_len = RTA_LENGTH(bclen); + iov[1] = (struct iovec){ &rta, sizeof(rta) }; + iov[2] = (struct iovec){ bc, bclen }; + req.nlh.nlmsg_len += RTA_LENGTH(bclen); + iovlen = 3; + } } msg = (struct msghdr) { .msg_name = (void *)&nladdr, .msg_namelen = sizeof(nladdr), .msg_iov = iov, - .msg_iovlen = f->f ? 3 : 1, + .msg_iovlen = iovlen, }; if (sendmsg(fd, &msg, 0) < 0) { @@ -2194,6 +2212,7 @@ static int sockdiag_send(int family, int fd, int protocol, struct filter *f) struct msghdr msg; struct rtattr rta; struct iovec iov[3]; + int iovlen = 1; if (family == PF_UNSPEC) return tcpdiag_send(fd, protocol, f); @@ -2222,18 +2241,21 @@ static int sockdiag_send(int family, int fd, int protocol, struct filter *f) }; if (f->f) { bclen = ssfilter_bytecompile(f->f, &bc); - rta.rta_type = INET_DIAG_REQ_BYTECODE; - rta.rta_len = RTA_LENGTH(bclen); - iov[1] = (struct iovec){ &rta, sizeof(rta) }; - iov[2] = (struct iovec){ bc, bclen }; - req.nlh.nlmsg_len += RTA_LENGTH(bclen); + if (bclen) { + rta.rta_type = INET_DIAG_REQ_BYTECODE; + rta.rta_len = RTA_LENGTH(bclen); + iov[1] = (struct iovec){ &rta, sizeof(rta) }; + iov[2] = (struct iovec){ bc, bclen }; + req.nlh.nlmsg_len += RTA_LENGTH(bclen); + iovlen = 3; + } } msg = (struct msghdr) { .msg_name = (void *)&nladdr, .msg_namelen = sizeof(nladdr), .msg_iov = iov, - .msg_iovlen = f->f ? 3 : 1, + .msg_iovlen = iovlen, }; if (sendmsg(fd, &msg, 0) < 0) { -- 2.1.4