IP_PKTINFO(2const) — Linux manual page

IP_PKTINFO(2const)                                     IP_PKTINFO(2const)

NAME         top

       IP_PKTINFO - information about the incoming packet

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <netinet/in.h>  /* Definition of IP* constants */
       #include <sys/socket.h>

       int setsockopt(int sockfd, IPPROTO_IP, IP_PKTINFO,
                      const int *enable, sizeof(int));

DESCRIPTION         top

       Pass an IP_PKTINFO ancillary message that contains a
       in_pktinfo(2type) structure that supplies some information about
       the incoming packet.  This works only for datagram oriented
       sockets.

       The argument is a flag that tells the socket whether the
       IP_PKTINFO message should be passed or not.

       The message itself can be sent/retrieved only as a control message
       with a packet using recvmsg(2) or sendmsg(2).

       Not supported for SOCK_STREAM sockets.

ERRORS         top

       See IPPROTO_IP(2const).  See setsockopt(2).  See ip(7).

VERSIONS         top

       Some BSD sockets implementations provide IP_RCVDSTADDR and
       IP_RECVIF socket options to get the destination address and the
       interface of received datagrams.  Linux has the more general
       IP_PKTINFO for the same task.

STANDARDS         top

       Linux.

HISTORY         top

       Linux 2.2.

SEE ALSO         top

       in_pktinfo(2const), IPPROTO_IP(2const), setsockopt(2), ip(7)

COLOPHON         top

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Linux man-pages 6.18            2025-12-01             IP_PKTINFO(2const)

Pages that refer to this page: in_pktinfo(2type),  IPPROTO_IP(2const)

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