d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

MFC: IP_MINTTL socket option.

Browse Source 
Approved by:	re (scottl)
This commit is contained in:
andre 2005-10-01 15:56:44 +00:00
parent 25968c47c3
commit 1d50cd7eb9
7 changed files with 36 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
share/man/man4/ip.4
View File

@ -32,7 +32,7 @@
.\" @(#)ip.4 8.2 (Berkeley) 11/30/93
.\" $FreeBSD$
.\"
.Dd March 23, 2005
.Dd August 22, 2005
.Dt IP 4
.Os
.Sh NAME
@ -113,6 +113,14 @@ int ttl = 60; /* max = 255 */
setsockopt(s, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
.Ed
.Pp
.Dv IP_MINTTL
may be used to set the minimum acceptable TTL a packet must have when
received on a socket.
All packets with a lower TTL are silently dropped.
This option is only really useful when set to 255 preventing packets
from outside the directly connected networks reaching local listeners
on sockets.
.Pp
If the
.Dv IP_RECVDSTADDR
option is enabled on a

1
sys/netinet/in.h
View File

@ -415,6 +415,7 @@ __END_DECLS
#define IP_DUMMYNET_GET 64 /* get entire dummynet pipes */
#define IP_RECVTTL 65 /* bool; receive IP TTL w/dgram */
#define IP_MINTTL 66 /* minimum TTL for packet or drop */
/*
* Defaults and limits for options

1
sys/netinet/in_pcb.h
View File

@ -133,6 +133,7 @@ struct inpcb {
#define INP_ONESBCAST 0x10 /* send all-ones broadcast */
u_char inp_ip_ttl; /* time to live proto */
u_char inp_ip_p; /* protocol proto */
u_char inp_ip_minttl; /* minimum TTL or drop */
/* protocol dependent part; options */
struct {

14
sys/netinet/ip_output.c
View File

@ -1189,6 +1189,7 @@ ip_ctloutput(so, sopt)
case IP_TOS:
case IP_TTL:
case IP_MINTTL:
case IP_RECVOPTS:
case IP_RECVRETOPTS:
case IP_RECVDSTADDR:
@ -1209,6 +1210,14 @@ ip_ctloutput(so, sopt)
case IP_TTL:
inp->inp_ip_ttl = optval;
break;
case IP_MINTTL:
if (optval > 0 && optval <= MAXTTL)
inp->inp_ip_minttl = optval;
else
error = EINVAL;
break;
#define OPTSET(bit) do { \
INP_LOCK(inp); \
if (optval) \
@ -1333,6 +1342,7 @@ ip_ctloutput(so, sopt)
case IP_TOS:
case IP_TTL:
case IP_MINTTL:
case IP_RECVOPTS:
case IP_RECVRETOPTS:
case IP_RECVDSTADDR:
@ -1351,6 +1361,10 @@ ip_ctloutput(so, sopt)
optval = inp->inp_ip_ttl;
break;
case IP_MINTTL:
optval = inp->inp_ip_minttl;
break;
#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
case IP_RECVOPTS:

3
sys/netinet/raw_ip.c
View File

@ -157,6 +157,9 @@ raw_append(struct inpcb *last, struct ip *ip, struct mbuf *n)
if (!policyfail && mac_check_inpcb_deliver(last, n) != 0)
policyfail = 1;
#endif
/* Check the minimum TTL for socket. */
if (last->inp_ip_minttl && last->inp_ip_minttl > ip->ip_ttl)
policyfail = 1;
if (!policyfail) {
struct mbuf *opts = NULL;
struct socket *so;

5
sys/netinet/tcp_input.c
View File

@ -740,6 +740,11 @@ findpcb:
goto dropwithreset;
}
INP_LOCK(inp);
/* Check the minimum TTL for socket. */
if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl)
goto drop;
if (inp->inp_vflag & INP_TIMEWAIT) {
/*
* The only option of relevance is TOF_CC, and only if

3
sys/netinet/udp_usrreq.c
View File

@ -384,6 +384,9 @@ udp_input(m, off)
return;
}
INP_LOCK(inp);
/* Check the minimum TTL for socket. */
if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl)
goto badheadlocked;
udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
INP_UNLOCK(inp);
INP_INFO_RUNLOCK(&udbinfo);