[PATCH 01/04]: pcap-linux: convert to recvmsg()

[Patrick McHardy <kaber () trash net>]

pcap-linux: convert to recvmsg()

From: Patrick McHardy <kaber () trash net>

Convert pcap-linux to use recvmsg() as preparation for using PACKET_AUXDATA
cmsgs.
---

 pcap-linux.c |   23 ++++++++++++++++-------
 1 files changed, 16 insertions(+), 7 deletions(-)


diff --git a/pcap-linux.c b/pcap-linux.c
index d9f9f10..8d9d302 100644
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -625,10 +625,10 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata)
 #else
        struct sockaddr         from;
 #endif
-       socklen_t               fromlen;
        int                     packet_len, caplen;
        struct pcap_pkthdr      pcap_header;
-
+       struct iovec            iov;
+       struct msghdr           msg;
 #ifdef HAVE_PF_PACKET_SOCKETS
        /*
         * If this is a cooked device, leave extra room for a
@@ -662,6 +662,18 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata)
         * get notified of "network down" events.
         */
        bp = handle->buffer + handle->offset;
+
+       msg.msg_name            = &from;
+       msg.msg_namelen         = sizeof(from);
+       msg.msg_iov             = &iov;
+       msg.msg_iovlen          = 1;
+       msg.msg_control         = NULL;
+       msg.msg_controllen      = 0;
+       msg.msg_flags           = 0;
+
+       iov.iov_len             = handle->bufsize - offset;
+       iov.iov_base            = bp + offset;
+
        do {
                /*
                 * Has "pcap_breakloop()" been called?
@@ -675,11 +687,8 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata)
                        handle->break_loop = 0;
                        return -2;
                }
-               fromlen = sizeof(from);
-               packet_len = recvfrom(
-                       handle->fd, bp + offset,
-                       handle->bufsize - offset, MSG_TRUNC,
-                       (struct sockaddr *) &from, &fromlen);
+
+               packet_len = recvmsg(handle->fd, &msg, MSG_TRUNC);
        } while (packet_len == -1 && (errno == EINTR || errno == ENETDOWN));
 
        /* Check if an error occured */

-
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