From 13651224c00b74a02c731b7840577f14e0311c83 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 16 Feb 2022 17:21:16 -0800 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ipv6/ip6_output.c | 1 + net/ipv6/ping.c | 21 ++++++++++++++++----- 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 0c6c971ce0a5..3286b64ec03d 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -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)); diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index d5544cf67ffe..ff033d16549e 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -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,