net: ipmr: add support for dumping routing tables over netlink

The ipmr /proc interface (ip_mr_cache) can't be extended to dump routes
from any tables but the main table in a backwards compatible fashion since
the output format ends in a variable amount of output interfaces.

Introduce a new netlink interface to dump multicast routes from all tables,
similar to the netlink interface for regular routes.

Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Patrick McHardy 2010-04-26 16:02:08 +02:00
parent 25239cee7e
commit cb6a4e461f

View File

@ -128,8 +128,8 @@ static int ip_mr_forward(struct net *net, struct mr_table *mrt,
int local);
static int ipmr_cache_report(struct mr_table *mrt,
struct sk_buff *pkt, vifi_t vifi, int assert);
static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
struct mfc_cache *c, struct rtmsg *rtm);
static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
struct mfc_cache *c, struct rtmsg *rtm);
static void ipmr_expire_process(unsigned long arg);
#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
@ -831,7 +831,7 @@ static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
if (ip_hdr(skb)->version == 0) {
struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
if (ipmr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {
if (__ipmr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {
nlh->nlmsg_len = (skb_tail_pointer(skb) -
(u8 *)nlh);
} else {
@ -1904,9 +1904,8 @@ static int pim_rcv(struct sk_buff * skb)
}
#endif
static int
ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, struct mfc_cache *c,
struct rtmsg *rtm)
static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
struct mfc_cache *c, struct rtmsg *rtm)
{
int ct;
struct rtnexthop *nhp;
@ -1994,11 +1993,93 @@ int ipmr_get_route(struct net *net,
if (!nowait && (rtm->rtm_flags&RTM_F_NOTIFY))
cache->mfc_flags |= MFC_NOTIFY;
err = ipmr_fill_mroute(mrt, skb, cache, rtm);
err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
read_unlock(&mrt_lock);
return err;
}
static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
u32 pid, u32 seq, struct mfc_cache *c)
{
struct nlmsghdr *nlh;
struct rtmsg *rtm;
nlh = nlmsg_put(skb, pid, seq, RTM_NEWROUTE, sizeof(*rtm), NLM_F_MULTI);
if (nlh == NULL)
return -EMSGSIZE;
rtm = nlmsg_data(nlh);
rtm->rtm_family = RTNL_FAMILY_IPMR;
rtm->rtm_dst_len = 32;
rtm->rtm_src_len = 32;
rtm->rtm_tos = 0;
rtm->rtm_table = mrt->id;
NLA_PUT_U32(skb, RTA_TABLE, mrt->id);
rtm->rtm_type = RTN_MULTICAST;
rtm->rtm_scope = RT_SCOPE_UNIVERSE;
rtm->rtm_protocol = RTPROT_UNSPEC;
rtm->rtm_flags = 0;
NLA_PUT_BE32(skb, RTA_SRC, c->mfc_origin);
NLA_PUT_BE32(skb, RTA_DST, c->mfc_mcastgrp);
if (__ipmr_fill_mroute(mrt, skb, c, rtm) < 0)
goto nla_put_failure;
return nlmsg_end(skb, nlh);
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct mr_table *mrt;
struct mfc_cache *mfc;
unsigned int t = 0, s_t;
unsigned int h = 0, s_h;
unsigned int e = 0, s_e;
s_t = cb->args[0];
s_h = cb->args[1];
s_e = cb->args[2];
read_lock(&mrt_lock);
ipmr_for_each_table(mrt, net) {
if (t < s_t)
goto next_table;
if (t > s_t)
s_h = 0;
for (h = s_h; h < MFC_LINES; h++) {
list_for_each_entry(mfc, &mrt->mfc_cache_array[h], list) {
if (e < s_e)
goto next_entry;
if (ipmr_fill_mroute(mrt, skb,
NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq,
mfc) < 0)
goto done;
next_entry:
e++;
}
e = s_e = 0;
}
s_h = 0;
next_table:
t++;
}
done:
read_unlock(&mrt_lock);
cb->args[2] = e;
cb->args[1] = h;
cb->args[0] = t;
return skb->len;
}
#ifdef CONFIG_PROC_FS
/*
* The /proc interfaces to multicast routing /proc/ip_mr_cache /proc/ip_mr_vif
@ -2355,6 +2436,7 @@ int __init ip_mr_init(void)
goto add_proto_fail;
}
#endif
rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE, NULL, ipmr_rtm_dumproute);
return 0;
#ifdef CONFIG_IP_PIMSM_V2