From f02db315b8d888570cb0d4496cfbb7e4acb047cb Mon Sep 17 00:00:00 2001 From: Francesco Fusco Date: Tue, 24 Sep 2013 15:43:08 +0200 Subject: [PATCH] ipv4: IP_TOS and IP_TTL can be specified as ancillary data This patch enables the IP_TTL and IP_TOS values passed from userspace to be stored in the ipcm_cookie struct. Three fields are added to the struct: - the TTL, expressed as __u8. The allowed values are in the [1-255]. A value of 0 means that the TTL is not specified. - the TOS, expressed as __s16. The allowed values are in the range [0,255]. A value of -1 means that the TOS is not specified. - the priority, expressed as a char and computed when handling the ancillary data. Signed-off-by: Francesco Fusco Signed-off-by: David S. Miller --- include/net/ip.h | 3 +++ net/ipv4/ip_sockglue.c | 20 +++++++++++++++++++- 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/include/net/ip.h b/include/net/ip.h index c1f192b..0135f38 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -56,6 +56,9 @@ struct ipcm_cookie { int oif; struct ip_options_rcu *opt; __u8 tx_flags; + __u8 ttl; + __s16 tos; + char priority; }; #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index d9c4f11..56e34457 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -189,7 +189,7 @@ EXPORT_SYMBOL(ip_cmsg_recv); int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc) { - int err; + int err, val; struct cmsghdr *cmsg; for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { @@ -215,6 +215,24 @@ int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc) ipc->addr = info->ipi_spec_dst.s_addr; break; } + case IP_TTL: + if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) + return -EINVAL; + val = *(int *)CMSG_DATA(cmsg); + if (val < 1 || val > 255) + return -EINVAL; + ipc->ttl = val; + break; + case IP_TOS: + if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) + return -EINVAL; + val = *(int *)CMSG_DATA(cmsg); + if (val < 0 || val > 255) + return -EINVAL; + ipc->tos = val; + ipc->priority = rt_tos2priority(ipc->tos); + break; + default: return -EINVAL; } -- 2.7.4