On Wed, Jun 15, 2016 at 07:43:37PM +0200, Vincent Gross wrote:
> rev3 below.
>
> I fixed the line length, the useless bzero(), and also the wording in
> ip.4
>
> Ok ?
OK bluhm@
>
> Index: sys/netinet/in.h
> ===================================================================
> RCS file: /cvs/src/sys/netinet/in.h,v
> retrieving revision 1.115
> diff -u -p -r1.115 in.h
> --- sys/netinet/in.h 20 Oct 2015 20:22:42 -0000 1.115
> +++ sys/netinet/in.h 15 Jun 2016 17:37:11 -0000
> @@ -307,6 +307,7 @@ struct ip_opts {
> #define IP_RECVRTABLE 35 /* bool; receive rdomain w/dgram */
> #define IP_IPSECFLOWINFO 36 /* bool; IPsec flow info for dgram */
> #define IP_IPDEFTTL 37 /* int; IP TTL system default */
> +#define IP_SENDSRCADDR 38 /* struct in_addr; source address
> to use */
>
> #define IP_RTABLE 0x1021 /* int; routing table, see SO_RTABLE */
> #define IP_DIVERTFL 0x1022 /* int; divert direction flag opt */
> Index: sys/netinet/udp_usrreq.c
> ===================================================================
> RCS file: /cvs/src/sys/netinet/udp_usrreq.c,v
> retrieving revision 1.212
> diff -u -p -r1.212 udp_usrreq.c
> --- sys/netinet/udp_usrreq.c 15 Jun 2016 16:06:35 -0000 1.212
> +++ sys/netinet/udp_usrreq.c 15 Jun 2016 17:37:11 -0000
> @@ -888,6 +888,7 @@ udp_output(struct inpcb *inp, struct mbu
> struct sockaddr_in *sin = NULL;
> struct udpiphdr *ui;
> u_int32_t ipsecflowinfo = 0;
> + struct sockaddr_in src_sin;
> int len = m->m_pkthdr.len;
> struct in_addr *laddr;
> int error = 0;
> @@ -906,6 +907,8 @@ udp_output(struct inpcb *inp, struct mbu
> goto release;
> }
>
> + memset(&src_sin, 0, sizeof(src_sin));
> +
> if (control) {
> u_int clen;
> struct cmsghdr *cm;
> @@ -939,9 +942,20 @@ udp_output(struct inpcb *inp, struct mbu
> cm->cmsg_level == IPPROTO_IP &&
> cm->cmsg_type == IP_IPSECFLOWINFO) {
> ipsecflowinfo = *(u_int32_t *)CMSG_DATA(cm);
> - break;
> - }
> + } else
> #endif
> + if (cm->cmsg_len == CMSG_LEN(sizeof(struct in_addr)) &&
> + cm->cmsg_level == IPPROTO_IP &&
> + cm->cmsg_type == IP_SENDSRCADDR) {
> + memcpy(&src_sin.sin_addr, CMSG_DATA(cm),
> + sizeof(struct in_addr));
> + src_sin.sin_family = AF_INET;
> + src_sin.sin_len = sizeof(src_sin);
> + /* no check on reuse when sin->sin_port == 0 */
> + if ((error = in_pcbaddrisavail(inp, &src_sin,
> + 0, curproc)))
> + goto release;
> + }
> clen -= CMSG_ALIGN(cm->cmsg_len);
> cmsgs += CMSG_ALIGN(cm->cmsg_len);
> } while (clen);
> @@ -979,6 +993,17 @@ udp_output(struct inpcb *inp, struct mbu
> splx(s);
> if (error)
> goto release;
> + }
> +
> + if (src_sin.sin_len > 0 &&
> + src_sin.sin_addr.s_addr != INADDR_ANY &&
> + src_sin.sin_addr.s_addr != inp->inp_laddr.s_addr) {
> + src_sin.sin_port = inp->inp_lport;
> + if (inp->inp_laddr.s_addr != INADDR_ANY &&
> + (error =
> + in_pcbaddrisavail(inp, &src_sin, 0, curproc)))
> + goto release;
> + laddr = &src_sin.sin_addr;
> }
> } else {
> if (inp->inp_faddr.s_addr == INADDR_ANY) {
> Index: share/man/man4/ip.4
> ===================================================================
> RCS file: /cvs/src/share/man/man4/ip.4,v
> retrieving revision 1.38
> diff -u -p -r1.38 ip.4
> --- share/man/man4/ip.4 20 Oct 2015 22:08:19 -0000 1.38
> +++ share/man/man4/ip.4 15 Jun 2016 17:37:12 -0000
> @@ -290,6 +290,34 @@ cmsg_len = CMSG_LEN(sizeof(u_int))
> cmsg_level = IPPROTO_IP
> cmsg_type = IP_RECVRTABLE
> .Ed
> +.Pp
> +When sending on a
> +.Dv SOCK_DGRAM
> +socket with
> +.Xr sendmsg 2
> +, the source address to be used can be passed as ancillary data with a type
> code of
> +.Dv IP_SENDSRCADDR .
> +The
> +.Va msg_control
> +field in the
> +.Vt msghdr
> +structure should point to a buffer that contains a
> +.Vt cmsghdr
> +structure followed by the requested source address.
> +The
> +.Vt cmsghdr
> +fields should have the following values:
> +.Bd -literal -offset indent
> +cmsg_len = CMSG_LEN(sizeof(struct in_addr))
> +cmsg_level = IPPROTO_IP
> +cmsg_type = IP_SENDSRCADDR
> +.Ed
> +.Pp
> +The same checks and restrictions as for
> +.Xr bind 2
> +apply, unless the socket is bound to
> +.Dv INADDR_ANY .
> +In this case, there is no source address overlap check.
> .Ss "Multicast Options"
> .Tn IP
> multicasting is supported only on
