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Fix long-standing issue with interface routes being unprotected:

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Use RTM_PINNED flag to mark route as immutable.
Forbid deleting immutable routes without special rtrequest1_fib() flag.
Adding interface address with prefix already in route table is handled
by atomically deleting old prefix and adding interface one.

Discussed with:	andre, eri
MFC after:	3 weeks
This commit is contained in:
Alexander V. Chernikov 2013-03-08 20:33:50 +00:00
parent 5cda6006e4
commit 3034f43f2f
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=248070
3 changed files with 41 additions and 4 deletions
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3
sys/net/if.c
View File

@ -1357,7 +1357,8 @@ if_rtdel(struct radix_node *rn, void *arg)
return (0);
err = rtrequest_fib(RTM_DELETE, rt_key(rt), rt->rt_gateway,
rt_mask(rt), rt->rt_flags|RTF_RNH_LOCKED,
rt_mask(rt),
rt->rt_flags|RTF_RNH_LOCKED|RTF_PINNED,
(struct rtentry **) NULL, rt->rt_fibnum);
if (err) {
log(LOG_WARNING, "if_rtdel: error %d\n", err);

40
sys/net/route.c
View File

@ -1112,6 +1112,14 @@ rtrequest1_fib(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt,
error = 0;
}
#endif
if ((flags & RTF_PINNED) == 0) {
/* Check if target route can be deleted */
rt = (struct rtentry *)rnh->rnh_lookup(dst,
netmask, rnh);
if ((rt != NULL) && (rt->rt_flags & RTF_PINNED))
senderr(EADDRINUSE);
}
/*
* Remove the item from the tree and return it.
* Complain if it is not there and do no more processing.
@ -1430,6 +1438,7 @@ rtinit1(struct ifaddr *ifa, int cmd, int flags, int fibnum)
int didwork = 0;
int a_failure = 0;
static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
struct radix_node_head *rnh;
if (flags & RTF_HOST) {
dst = ifa->ifa_dstaddr;
@ -1488,7 +1497,6 @@ rtinit1(struct ifaddr *ifa, int cmd, int flags, int fibnum)
*/
for ( fibnum = startfib; fibnum <= endfib; fibnum++) {
if (cmd == RTM_DELETE) {
struct radix_node_head *rnh;
struct radix_node *rn;
/*
* Look up an rtentry that is in the routing tree and
@ -1538,7 +1546,8 @@ rtinit1(struct ifaddr *ifa, int cmd, int flags, int fibnum)
*/
bzero((caddr_t)&info, sizeof(info));
info.rti_ifa = ifa;
info.rti_flags = flags | (ifa->ifa_flags & ~IFA_RTSELF);
info.rti_flags = flags |
(ifa->ifa_flags & ~IFA_RTSELF) | RTF_PINNED;
info.rti_info[RTAX_DST] = dst;
/*
* doing this for compatibility reasons
@ -1550,6 +1559,33 @@ rtinit1(struct ifaddr *ifa, int cmd, int flags, int fibnum)
info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr;
info.rti_info[RTAX_NETMASK] = netmask;
error = rtrequest1_fib(cmd, &info, &rt, fibnum);
if ((error == EEXIST) && (cmd == RTM_ADD)) {
/*
* Interface route addition failed.
* Atomically delete current prefix generating
* RTM_DELETE message, and retry adding
* interface prefix.
*/
rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
RADIX_NODE_HEAD_LOCK(rnh);
/* Delete old prefix */
info.rti_ifa = NULL;
info.rti_flags = RTF_RNH_LOCKED;
error = rtrequest1_fib(RTM_DELETE, &info, &rt, fibnum);
if (error == 0) {
info.rti_ifa = ifa;
info.rti_flags = flags | RTF_RNH_LOCKED |
(ifa->ifa_flags & ~IFA_RTSELF) | RTF_PINNED;
error = rtrequest1_fib(cmd, &info, &rt, fibnum);
}
RADIX_NODE_HEAD_UNLOCK(rnh);
}
if (error == 0 && rt != NULL) {
/*
* notify any listening routing agents of the change

2
sys/net/route.h
View File

@ -176,7 +176,7 @@ struct ortentry {
/* 0x20000 unused, was RTF_WASCLONED */
#define RTF_PROTO3 0x40000 /* protocol specific routing flag */
/* 0x80000 unused */
#define RTF_PINNED 0x100000 /* future use */
#define RTF_PINNED 0x100000 /* route is immutable */
#define RTF_LOCAL 0x200000 /* route represents a local address */
#define RTF_BROADCAST 0x400000 /* route represents a bcast address */
#define RTF_MULTICAST 0x800000 /* route represents a mcast address */