Auto merge of #1184 - pusateri:recvif, r=gnzlbg

Add IP_RECVIF to BSD and IP_RECVDSTADDR to apple.

FreeBSD/OpenBSD do not support IP_PKTINFO for IPv4 but use IP_RECVIF for interface index and IP_RECVDSTADDR for destination address.
NetBSD and macOS also support IP_RECVIF and IP_RECVDSTADDR in addition to IP_PKTINFO.
(For IPv6, all use IPV6_PKTINFO)

Author: bors

src/unix/bsd/apple/mod.rs

@@ -1570,8 +1570,10 @@ pub const SOCK_RDM: ::c_int = 4;
 pub const SOCK_SEQPACKET: ::c_int = 5;
 pub const IP_TTL: ::c_int = 4;
 pub const IP_HDRINCL: ::c_int = 2;
+pub const IP_RECVDSTADDR: ::c_int = 7;
 pub const IP_ADD_MEMBERSHIP: ::c_int = 12;
 pub const IP_DROP_MEMBERSHIP: ::c_int = 13;
+pub const IP_RECVIF: ::c_int = 20;
 pub const IP_PKTINFO: ::c_int = 26;
 pub const IP_RECVTOS: ::c_int = 27;
 pub const IPV6_JOIN_GROUP: ::c_int = 12;

src/unix/bsd/freebsdlike/mod.rs

@@ -664,6 +664,7 @@ pub const IP_RECVDSTADDR: ::c_int = 7;
 pub const IP_SENDSRCADDR: ::c_int = IP_RECVDSTADDR;
 pub const IP_ADD_MEMBERSHIP: ::c_int = 12;
 pub const IP_DROP_MEMBERSHIP: ::c_int = 13;
+pub const IP_RECVIF: ::c_int = 20;
 pub const IPV6_JOIN_GROUP: ::c_int = 12;
 pub const IPV6_LEAVE_GROUP: ::c_int = 13;
 pub const IPV6_RECVPKTINFO: ::c_int = 36;

src/unix/bsd/netbsdlike/netbsd/mod.rs

@@ -393,6 +393,7 @@ pub const F_GETNOSIGPIPE: ::c_int = 13;
 pub const F_SETNOSIGPIPE: ::c_int = 14;
 pub const F_MAXFD: ::c_int = 11;
 
+pub const IP_RECVIF: ::c_int = 20;
 pub const IP_PKTINFO: ::c_int = 25;
 pub const IP_RECVPKTINFO: ::c_int = 26;
 pub const IPV6_JOIN_GROUP: ::c_int = 12;

src/unix/bsd/netbsdlike/openbsdlike/mod.rs

@@ -319,6 +319,7 @@ pub const IPPROTO_DIVERT: ::c_int = 258;
 
 pub const IP_RECVDSTADDR: ::c_int = 7;
 pub const IP_SENDSRCADDR: ::c_int = IP_RECVDSTADDR;
+pub const IP_RECVIF: ::c_int = 30;
 
 // sys/netinet/in.h
 pub const TCP_MD5SIG: ::c_int = 0x04;