package/network/services/dnsmasq/patches/0048-Fix-cmsg-3-API-usage-on-OpenBSD.patch

   1 From c6cc455dd191fbea56ee14a0ef88a7d655a6fe9a Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?J=C3=A9r=C3=A9mie=20Courr=C3=A8ges-Anglas?= <jca@wxcvbn.org>
   3 Date: Fri, 22 Mar 2019 10:56:13 +0100
   4 Subject: [PATCH 48/57] Fix cmsg(3) API usage on OpenBSD
   5
   6 msg_controllen should be set using CMSG_SPACE() to account for padding.
   7 RFC3542 provides more details:
   8
   9   While sending an application may or may not include padding at the end
  10   of last ancillary data in msg_controllen and implementations must
  11   accept both as valid.
  12
  13 At least OpenBSD rejects control messages if msg_controllen doesn't
  14 account for padding, so use CMSG_SPACE() for maximal portability.  This
  15 is consistent with the example provided in the Linux cmsg(3) manpage.
  16
  17 Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
  18 ---
  19  src/forward.c | 9 ++++++---
  20  1 file changed, 6 insertions(+), 3 deletions(-)
  21
  22 --- a/src/forward.c
  23 +++ b/src/forward.c
  24 @@ -65,13 +65,15 @@ int send_from(int fd, int nowild, char *
  25           struct in_pktinfo p;
  26           p.ipi_ifindex = 0;
  27           p.ipi_spec_dst = source->addr4;
  28 +         msg.msg_controllen = CMSG_SPACE(sizeof(struct in_pktinfo));
  29           memcpy(CMSG_DATA(cmptr), &p, sizeof(p));
  30 -         msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
  31 +         cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
  32           cmptr->cmsg_level = IPPROTO_IP;
  33           cmptr->cmsg_type = IP_PKTINFO;
  34  #elif defined(IP_SENDSRCADDR)
  35 +         msg.msg_controllen = CMSG_SPACE(sizeof(struct in_addr));
  36           memcpy(CMSG_DATA(cmptr), &(source->addr4), sizeof(source->addr4));
  37 -         msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_addr));
  38 +         cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_addr));
  39           cmptr->cmsg_level = IPPROTO_IP;
  40           cmptr->cmsg_type = IP_SENDSRCADDR;
  41  #endif
  42 @@ -81,8 +83,9 @@ int send_from(int fd, int nowild, char *
  43           struct in6_pktinfo p;
  44           p.ipi6_ifindex = iface; /* Need iface for IPv6 to handle link-local addrs */
  45           p.ipi6_addr = source->addr6;
  46 +         msg.msg_controllen = CMSG_SPACE(sizeof(struct in6_pktinfo));
  47           memcpy(CMSG_DATA(cmptr), &p, sizeof(p));
  48 -         msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
  49 +         cmptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
  50           cmptr->cmsg_type = daemon->v6pktinfo;
  51           cmptr->cmsg_level = IPPROTO_IPV6;
  52         }