net: ping6: support setting basic SOL_IPV6 options via cmsg

Support setting IPV6_HOPLIMIT, IPV6_TCLASS, IPV6_DONTFRAG
during sendmsg via SOL_IPV6 cmsgs.

tclass and dontfrag are init'ed from struct ipv6_pinfo in
ipcm6_init_sk(), while hlimit is inited to -1, so we need
to handle it being populated via cmsg explicitly.

Leave extension headers and flowlabel unimplemented.
Those are slightly more laborious to test and users
seem to primarily care about IPV6_TCLASS.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jakub Kicinski 2022-02-16 17:21:16 -08:00 committed by David S. Miller
parent d54f16c7fa
commit 13651224c0
2 changed files with 17 additions and 5 deletions

View File

@ -1487,6 +1487,7 @@ static int __ip6_append_data(struct sock *sk,
if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
(sk->sk_protocol == IPPROTO_UDP ||
sk->sk_protocol == IPPROTO_ICMPV6 ||
sk->sk_protocol == IPPROTO_RAW)) {
ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
sizeof(struct ipv6hdr));

View File

@ -101,11 +101,21 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
ipc6.sockc.tsflags = sk->sk_tsflags;
ipc6.sockc.mark = sk->sk_mark;
err = sock_cmsg_send(sk, msg, &ipc6.sockc);
if (err)
return err;
if (msg->msg_controllen) {
struct ipv6_txoptions opt = {};
/* TODO: use ip6_datagram_send_ctl to get options from cmsg */
opt.tot_len = sizeof(opt);
ipc6.opt = &opt;
err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6);
if (err < 0)
return err;
/* Changes to txoptions and flow info are not implemented, yet.
* Drop the options, fl6 is wiped below.
*/
ipc6.opt = NULL;
}
memset(&fl6, 0, sizeof(fl6));
@ -140,7 +150,8 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
pfh.wcheck = 0;
pfh.family = AF_INET6;
ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
if (ipc6.hlimit < 0)
ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
lock_sock(sk);
err = ip6_append_data(sk, ping_getfrag, &pfh, len,