fix linux netfilter with a max packet count

diff --git a/pcap-netfilter-linux.c b/pcap-netfilter-linux.c
index a53cc37e0a2d23131163a34b8cb345db5949bfd3..25df335dbfffaa495347a13bc36548c90372cd8f 100644 (file)
--- a/pcap-netfilter-linux.c
+++ b/pcap-netfilter-linux.c
@@ -89,28 +89,44 @@ static int
 netfilter_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
 {
        struct pcap_netfilter *handlep = handle->priv;
-       const unsigned char *buf;
+       register u_char *bp, *ep;
        int count = 0;
        int len;
 
+       if (handle->break_loop) {
+               handle->break_loop = 0;
+               return (PCAP_ERROR_BREAK);
+       }
+       len = handle->cc;
+       if (len == 0) {
+               do {
+                       len = recv(handle->fd, handle->buffer, handle->bufsize, 0);
+                       if(errno == ENOBUFS) handlep->packets_nobufs++;
+               } while ((len == -1) && (errno == EINTR || errno == ENOBUFS));
+
+               if (len < 0) {
+                       pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't receive packet %d:%s", errno, pcap_strerror(errno));
+                       return -1;
+               }
+
+               bp = (unsigned char *)handle->buffer;
+       } else
+               bp = handle->bp;
+       ep = bp + len;
        /* ignore interrupt system call error */
-       do {
-               len = recv(handle->fd, handle->buffer, handle->bufsize, 0);
+       while (bp < ep) {
                if (handle->break_loop) {
-                       handle->break_loop = 0;
-                       return -2;
+                       handle->bp = bp;
+                       handle->cc = ep - bp;
+                       if (handle->cc < 0)
+                               handle->cc = 0;
+                       if (count == 0) {
+                               handle->break_loop = 0;
+                               return (PCAP_ERROR_BREAK);
+                       } else
+                               return (count);
                }
-               if(errno == ENOBUFS) handlep->packets_nobufs++;
-       } while ((len == -1) && (errno == EINTR || errno == ENOBUFS));
-
-       if (len < 0) {
-               pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't receive packet %d:%s", errno, pcap_strerror(errno));
-               return -1;
-       }
-
-       buf = (unsigned char *)handle->buffer;
-       while ((u_int)len >= NLMSG_SPACE(0)) {
-               const struct nlmsghdr *nlh = (const struct nlmsghdr *) buf;
+               const struct nlmsghdr *nlh = (const struct nlmsghdr *) bp;
                u_int32_t msg_len;
                nftype_t type = OTHER;
 
@@ -208,9 +224,17 @@ netfilter_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_c
                if (msg_len > (u_int)len)
                        msg_len = (u_int)len;
 
-               len -= msg_len;
-               buf += msg_len;
+               bp += msg_len;
+               if (count >= max_packets && !PACKET_COUNT_IS_UNLIMITED(max_packets)) {
+                       handle->bp = bp;
+                       handle->cc = ep - bp;
+                       if (handle->cc < 0)
+                               handle->cc = 0;
+                       return (count);
+               }
        }
+
+       handle->cc = 0;
        return count;
 }