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 <ffusco@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index d9c4f11..56e3445 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -189,7 +189,7 @@
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 @@
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;
}