svn commit: r318778 - stable/11/sys/netinet

[Andrey V. Elsukov]

Author: ae
Date: Wed May 24 09:03:46 2017
New Revision: 318778
URL: https://svnweb.freebsd.org/changeset/base/318778

Log:
  MFC r318399:
    Set M_BCAST and M_MCAST flags on mbuf sent via divert socket.
  
    r290383 has changed how mbufs sent by divert socket are handled.
    Previously they are always handled by slow path processing in ip_input().
    Now ip_tryforward() is invoked from ip_input() before in_broadcast() check.
    Since diverted packet lost all mbuf flags, it passes the broadcast check
    in ip_tryforward() due to missing M_BCAST flag. In the result the broadcast
    packet is forwarded to the wire instead of be consumed by network stack.
  
    Add in_broadcast() check to the div_output() function. And restore the
    M_BCAST flag if destination address is broadcast for the given network
    interface.
  
    PR:		209491

Modified:
  stable/11/sys/netinet/ip_divert.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/netinet/ip_divert.c
==============================================================================
--- stable/11/sys/netinet/ip_divert.c	Wed May 24 09:01:54 2017	(r318777)
+++ stable/11/sys/netinet/ip_divert.c	Wed May 24 09:03:46 2017	(r318778)
@@ -489,6 +489,14 @@ div_output(struct socket *so, struct mbu
 		/* Send packet to input processing via netisr */
 		switch (ip->ip_v) {
 		case IPVERSION:
+			/*
+			 * Restore M_BCAST flag when destination address is
+			 * broadcast. It is expected by ip_tryforward().
+			 */
+			if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)))
+				m->m_flags |= M_MCAST;
+			else if (in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif))
+				m->m_flags |= M_BCAST;
 			netisr_queue_src(NETISR_IP, (uintptr_t)so, m);
 			break;
 #ifdef INET6