* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
-#ifdef HAVE_CONFIG_H
#include <config.h>
-#endif
#include "pcap-int.h"
-
-#ifdef NEED_STRERROR_H
-#include "strerror.h"
-#endif
+#include "diag-control.h"
#include <errno.h>
#include <stdlib.h>
#include <linux/netfilter/nfnetlink_log.h>
#include <linux/netfilter/nfnetlink_queue.h>
-/* NOTE: if your program drops privilages after pcap_activate() it WON'T work with nfqueue.
+/* NOTE: if your program drops privileges after pcap_activate() it WON'T work with nfqueue.
* It took me quite some time to debug ;/
*
- * Sending any data to nfnetlink socket requires CAP_NET_ADMIN privilages,
- * and in nfqueue we need to send verdict reply after recving packet.
+ * Sending any data to nfnetlink socket requires CAP_NET_ADMIN privileges,
+ * and in nfqueue we need to send verdict reply after receiving packet.
*
- * In tcpdump you can disable dropping privilages with -Z root
+ * In tcpdump you can disable dropping privileges with -Z root
*/
#include "pcap-netfilter-linux.h"
struct pcap_netfilter *handlep = handle->priv;
register u_char *bp, *ep;
int count = 0;
- ssize_t len;
+ u_int cc;
/*
* Has "pcap_breakloop()" been called?
handle->break_loop = 0;
return PCAP_ERROR_BREAK;
}
- len = handle->cc;
- if (len == 0) {
+ cc = handle->cc;
+ if (cc == 0) {
/*
* The buffer is empty; refill it.
*
* to set handle->break_loop (we ignore it on other
* platforms as well).
*/
+ ssize_t read_ret;
+
do {
- len = recv(handle->fd, handle->buffer, handle->bufsize, 0);
+ read_ret = recv(handle->fd, handle->buffer, handle->bufsize, 0);
if (handle->break_loop) {
handle->break_loop = 0;
return PCAP_ERROR_BREAK;
}
- if (errno == ENOBUFS)
+ if (read_ret == -1 && errno == ENOBUFS)
handlep->packets_nobufs++;
- } while ((len == -1) && (errno == EINTR || errno == ENOBUFS));
+ } while ((read_ret == -1) && (errno == EINTR || errno == ENOBUFS));
- if (len < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
+ if (read_ret < 0) {
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
PCAP_ERRBUF_SIZE, errno, "Can't receive packet");
return PCAP_ERROR;
}
+ /*
+ * At this point, read_ret is guaranteed to be
+ * >= 0 and < p->bufsize; p->bufsize is a u_int,
+ * so its value is guaranteed to fit in cc, which
+ * is also a u_int.
+ */
+ cc = (u_int)read_ret;
bp = (unsigned char *)handle->buffer;
} else
bp = handle->bp;
- ep = bp + len;
+
+ /*
+ * Loop through each message.
+ *
+ * This assumes that a single buffer of message will have
+ * <= INT_MAX packets, so the message count doesn't overflow.
+ */
+ ep = bp + cc;
while (bp < ep) {
const struct nlmsghdr *nlh = (const struct nlmsghdr *) bp;
uint32_t msg_len;
*/
if (handle->break_loop) {
handle->bp = bp;
- handle->cc = (int)(ep - bp);
+ handle->cc = (u_int)(ep - bp);
if (count == 0) {
handle->break_loop = 0;
return PCAP_ERROR_BREAK;
} else
return count;
}
- if (ep - bp < NLMSG_SPACE(0)) {
+ /*
+ * NLMSG_SPACE(0) might be signed or might be unsigned,
+ * depending on whether the kernel defines NLMSG_ALIGNTO
+ * as 4, which older kernels do, or as 4U, which newer
+ * kernels do.
+ *
+ * ep - bp is of type ptrdiff_t, which is signed.
+ *
+ * To squelch warnings, we cast both to size_t, which
+ * is unsigned; ep >= bp, so the cast is safe.
+ */
+ if ((size_t)(ep - bp) < (size_t)NLMSG_SPACE(0)) {
/*
* There's less than one netlink message left
* in the buffer. Give up.
break;
}
- if (nlh->nlmsg_len < sizeof(struct nlmsghdr) || (u_int)len < nlh->nlmsg_len) {
- snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Message truncated: (got: %zd) (nlmsg_len: %u)", len, nlh->nlmsg_len);
+ if (nlh->nlmsg_len < sizeof(struct nlmsghdr) || cc < nlh->nlmsg_len) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Message truncated: (got: %u) (nlmsg_len: %u)", cc, nlh->nlmsg_len);
return -1;
}
gettimeofday(&pkth.ts, NULL);
if (handle->fcode.bf_insns == NULL ||
- pcap_filter(handle->fcode.bf_insns, payload, pkth.len, pkth.caplen))
+ pcapint_filter(handle->fcode.bf_insns, payload, pkth.len, pkth.caplen))
{
handlep->packets_read++;
callback(user, &pkth, payload);
* If the message length would run past the end of the
* buffer, truncate it to the remaining space in the
* buffer.
+ *
+ * To squelch warnings, we cast ep - bp to uint32_t, which
+ * is unsigned and is the type of msg_len; ep >= bp, and
+ * len should fit in 32 bits (either it's set from an int
+ * or it's set from a recv() call with a buffer size that's
+ * an int, and we're assuming either ILP32 or LP64), so
+ * the cast is safe.
*/
- if (msg_len > ep - bp)
+ if (msg_len > (uint32_t)(ep - bp))
msg_len = (uint32_t)(ep - bp);
bp += msg_len;
if (count >= max_packets && !PACKET_COUNT_IS_UNLIMITED(max_packets)) {
handle->bp = bp;
- handle->cc = (int)(ep - bp);
- if (handle->cc < 0)
- handle->cc = 0;
+ handle->cc = (u_int)(ep - bp);
return count;
}
}
netfilter_send_config_msg(const pcap_t *handle, uint16_t msg_type, int ack, u_int8_t family, u_int16_t res_id, const struct my_nfattr *mynfa)
{
char buf[1024] __attribute__ ((aligned));
+ memset(buf, 0, sizeof(buf));
struct nlmsghdr *nlh = (struct nlmsghdr *) buf;
struct nfgenmsg *nfg = (struct nfgenmsg *) (buf + sizeof(struct nlmsghdr));
static unsigned int seq_id;
if (!seq_id)
+DIAG_OFF_NARROWING
seq_id = time(NULL);
+DIAG_ON_NARROWING
++seq_id;
nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nfgenmsg));
nftype_t type = OTHER;
int i;
- if (strncmp(dev, NFLOG_IFACE, strlen(NFLOG_IFACE)) == 0) {
- dev += strlen(NFLOG_IFACE);
+ if (strncmp(dev, NFLOG_IFACE, strlen(NFLOG_IFACE)) == 0) {
+ dev += strlen(NFLOG_IFACE);
type = NFLOG;
} else if (strncmp(dev, NFQUEUE_IFACE, strlen(NFQUEUE_IFACE)) == 0) {
handle->offset = 0;
handle->read_op = netfilter_read_linux;
handle->inject_op = netfilter_inject_linux;
- handle->setfilter_op = install_bpf_program; /* no kernel filtering */
+ handle->setfilter_op = pcapint_install_bpf_program; /* no kernel filtering */
handle->setdirection_op = NULL;
handle->set_datalink_op = netfilter_set_datalink;
- handle->getnonblock_op = pcap_getnonblock_fd;
- handle->setnonblock_op = pcap_setnonblock_fd;
+ handle->getnonblock_op = pcapint_getnonblock_fd;
+ handle->setnonblock_op = pcapint_setnonblock_fd;
handle->stats_op = netfilter_stats_linux;
/* Create netlink socket */
handle->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER);
if (handle->fd < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
errno, "Can't create raw socket");
return PCAP_ERROR;
}
if (type == NFLOG) {
handle->linktype = DLT_NFLOG;
handle->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
- if (handle->dlt_list != NULL) {
- handle->dlt_list[0] = DLT_NFLOG;
- handle->dlt_list[1] = DLT_IPV4;
- handle->dlt_count = 2;
+ if (handle->dlt_list == NULL) {
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
+ PCAP_ERRBUF_SIZE, errno,
+ "Can't allocate DLT list");
+ goto close_fail;
}
-
+ handle->dlt_list[0] = DLT_NFLOG;
+ handle->dlt_list[1] = DLT_IPV4;
+ handle->dlt_count = 2;
} else
handle->linktype = DLT_IPV4;
handle->buffer = malloc(handle->bufsize);
if (!handle->buffer) {
- pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
errno, "Can't allocate dump buffer");
goto close_fail;
}
if (type == NFLOG) {
if (nflog_send_config_cmd(handle, 0, NFULNL_CFG_CMD_PF_UNBIND, AF_INET) < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
PCAP_ERRBUF_SIZE, errno,
"NFULNL_CFG_CMD_PF_UNBIND");
goto close_fail;
}
if (nflog_send_config_cmd(handle, 0, NFULNL_CFG_CMD_PF_BIND, AF_INET) < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
PCAP_ERRBUF_SIZE, errno, "NFULNL_CFG_CMD_PF_BIND");
goto close_fail;
}
/* Bind socket to the nflog groups */
for (i = 0; i < group_count; i++) {
if (nflog_send_config_cmd(handle, groups[i], NFULNL_CFG_CMD_BIND, AF_UNSPEC) < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
PCAP_ERRBUF_SIZE, errno,
- "Can't listen on group group index");
+ "Can't listen on group index");
goto close_fail;
}
if (nflog_send_config_mode(handle, groups[i], NFULNL_COPY_PACKET, handle->snapshot) < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
PCAP_ERRBUF_SIZE, errno,
"NFULNL_COPY_PACKET");
goto close_fail;
} else {
if (nfqueue_send_config_cmd(handle, 0, NFQNL_CFG_CMD_PF_UNBIND, AF_INET) < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
PCAP_ERRBUF_SIZE, errno, "NFQNL_CFG_CMD_PF_UNBIND");
goto close_fail;
}
if (nfqueue_send_config_cmd(handle, 0, NFQNL_CFG_CMD_PF_BIND, AF_INET) < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
PCAP_ERRBUF_SIZE, errno, "NFQNL_CFG_CMD_PF_BIND");
goto close_fail;
}
/* Bind socket to the nfqueue groups */
for (i = 0; i < group_count; i++) {
if (nfqueue_send_config_cmd(handle, groups[i], NFQNL_CFG_CMD_BIND, AF_UNSPEC) < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
PCAP_ERRBUF_SIZE, errno,
- "Can't listen on group group index");
+ "Can't listen on group index");
goto close_fail;
}
if (nfqueue_send_config_mode(handle, groups[i], NFQNL_COPY_PACKET, handle->snapshot) < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
PCAP_ERRBUF_SIZE, errno,
"NFQNL_COPY_PACKET");
goto close_fail;
/*
* Monitor mode doesn't apply to netfilter devices.
*/
- pcap_cleanup_live_common(handle);
+ pcapint_cleanup_live_common(handle);
return PCAP_ERROR_RFMON_NOTSUP;
}
* Set the socket buffer size to the specified value.
*/
if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, &handle->opt.buffer_size, sizeof(handle->opt.buffer_size)) == -1) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
+ pcapint_fmt_errmsg_for_errno(handle->errbuf,
PCAP_ERRBUF_SIZE, errno, "SO_RCVBUF");
goto close_fail;
}
return 0;
close_fail:
- pcap_cleanup_live_common(handle);
+ pcapint_cleanup_live_common(handle);
return PCAP_ERROR;
}
pcap_t *p;
/* Does this look like an netfilter device? */
- cp = strrchr(device, '/');
- if (cp == NULL)
- cp = device;
+ cp = device;
/* Does it begin with NFLOG_IFACE or NFQUEUE_IFACE? */
if (strncmp(cp, NFLOG_IFACE, sizeof NFLOG_IFACE - 1) == 0)
/* OK, it's probably ours. */
*is_ours = 1;
- p = pcap_create_common(ebuf, sizeof (struct pcap_netfilter));
+ p = PCAP_CREATE_COMMON(ebuf, struct pcap_netfilter);
if (p == NULL)
return (NULL);
/* if netlink is not supported this is not fatal */
if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT)
return 0;
- pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
+ pcapint_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
errno, "Can't open netlink socket");
return -1;
}
* The notion of "connected" vs. "disconnected" doesn't apply.
* XXX - what about "up" and "running"?
*/
- if (add_dev(devlistp, NFLOG_IFACE,
+ if (pcapint_add_dev(devlistp, NFLOG_IFACE,
PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
"Linux netfilter log (NFLOG) interface", err_str) == NULL)
return -1;
- if (add_dev(devlistp, NFQUEUE_IFACE,
+ if (pcapint_add_dev(devlistp, NFQUEUE_IFACE,
PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
"Linux netfilter queue (NFQUEUE) interface", err_str) == NULL)
return -1;
projects / libpcap / blobdiff