[IPv4]: FIB configuration using struct fib_config
Introduces struct fib_config replacing the ugly struct kern_rta
prone to ordering issues. Avoids creating faked netlink messages
for auto generated routes or requests via ioctl.
A new interface net/nexthop.h is added to help navigate through
nexthop configuration arrays.
A new struct nl_info will be used to carry the necessary netlink
information to be used for notifications later on.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index ad4c14f..acc18bd 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -253,42 +253,190 @@
#ifndef CONFIG_IP_NOSIOCRT
+static inline u32 sk_extract_addr(struct sockaddr *addr)
+{
+ return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
+}
+
+static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
+{
+ struct nlattr *nla;
+
+ nla = (struct nlattr *) ((char *) mx + len);
+ nla->nla_type = type;
+ nla->nla_len = nla_attr_size(4);
+ *(u32 *) nla_data(nla) = value;
+
+ return len + nla_total_size(4);
+}
+
+static int rtentry_to_fib_config(int cmd, struct rtentry *rt,
+ struct fib_config *cfg)
+{
+ u32 addr;
+ int plen;
+
+ memset(cfg, 0, sizeof(*cfg));
+
+ if (rt->rt_dst.sa_family != AF_INET)
+ return -EAFNOSUPPORT;
+
+ /*
+ * Check mask for validity:
+ * a) it must be contiguous.
+ * b) destination must have all host bits clear.
+ * c) if application forgot to set correct family (AF_INET),
+ * reject request unless it is absolutely clear i.e.
+ * both family and mask are zero.
+ */
+ plen = 32;
+ addr = sk_extract_addr(&rt->rt_dst);
+ if (!(rt->rt_flags & RTF_HOST)) {
+ u32 mask = sk_extract_addr(&rt->rt_genmask);
+
+ if (rt->rt_genmask.sa_family != AF_INET) {
+ if (mask || rt->rt_genmask.sa_family)
+ return -EAFNOSUPPORT;
+ }
+
+ if (bad_mask(mask, addr))
+ return -EINVAL;
+
+ plen = inet_mask_len(mask);
+ }
+
+ cfg->fc_dst_len = plen;
+ cfg->fc_dst = addr;
+
+ if (cmd != SIOCDELRT) {
+ cfg->fc_nlflags = NLM_F_CREATE;
+ cfg->fc_protocol = RTPROT_BOOT;
+ }
+
+ if (rt->rt_metric)
+ cfg->fc_priority = rt->rt_metric - 1;
+
+ if (rt->rt_flags & RTF_REJECT) {
+ cfg->fc_scope = RT_SCOPE_HOST;
+ cfg->fc_type = RTN_UNREACHABLE;
+ return 0;
+ }
+
+ cfg->fc_scope = RT_SCOPE_NOWHERE;
+ cfg->fc_type = RTN_UNICAST;
+
+ if (rt->rt_dev) {
+ char *colon;
+ struct net_device *dev;
+ char devname[IFNAMSIZ];
+
+ if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
+ return -EFAULT;
+
+ devname[IFNAMSIZ-1] = 0;
+ colon = strchr(devname, ':');
+ if (colon)
+ *colon = 0;
+ dev = __dev_get_by_name(devname);
+ if (!dev)
+ return -ENODEV;
+ cfg->fc_oif = dev->ifindex;
+ if (colon) {
+ struct in_ifaddr *ifa;
+ struct in_device *in_dev = __in_dev_get_rtnl(dev);
+ if (!in_dev)
+ return -ENODEV;
+ *colon = ':';
+ for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
+ if (strcmp(ifa->ifa_label, devname) == 0)
+ break;
+ if (ifa == NULL)
+ return -ENODEV;
+ cfg->fc_prefsrc = ifa->ifa_local;
+ }
+ }
+
+ addr = sk_extract_addr(&rt->rt_gateway);
+ if (rt->rt_gateway.sa_family == AF_INET && addr) {
+ cfg->fc_gw = addr;
+ if (rt->rt_flags & RTF_GATEWAY &&
+ inet_addr_type(addr) == RTN_UNICAST)
+ cfg->fc_scope = RT_SCOPE_UNIVERSE;
+ }
+
+ if (cmd == SIOCDELRT)
+ return 0;
+
+ if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
+ return -EINVAL;
+
+ if (cfg->fc_scope == RT_SCOPE_NOWHERE)
+ cfg->fc_scope = RT_SCOPE_LINK;
+
+ if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
+ struct nlattr *mx;
+ int len = 0;
+
+ mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
+ if (mx == NULL)
+ return -ENOMEM;
+
+ if (rt->rt_flags & RTF_MTU)
+ len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
+
+ if (rt->rt_flags & RTF_WINDOW)
+ len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
+
+ if (rt->rt_flags & RTF_IRTT)
+ len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
+
+ cfg->fc_mx = mx;
+ cfg->fc_mx_len = len;
+ }
+
+ return 0;
+}
+
/*
* Handle IP routing ioctl calls. These are used to manipulate the routing tables
*/
int ip_rt_ioctl(unsigned int cmd, void __user *arg)
{
+ struct fib_config cfg;
+ struct rtentry rt;
int err;
- struct kern_rta rta;
- struct rtentry r;
- struct {
- struct nlmsghdr nlh;
- struct rtmsg rtm;
- } req;
switch (cmd) {
case SIOCADDRT: /* Add a route */
case SIOCDELRT: /* Delete a route */
if (!capable(CAP_NET_ADMIN))
return -EPERM;
- if (copy_from_user(&r, arg, sizeof(struct rtentry)))
+
+ if (copy_from_user(&rt, arg, sizeof(rt)))
return -EFAULT;
+
rtnl_lock();
- err = fib_convert_rtentry(cmd, &req.nlh, &req.rtm, &rta, &r);
+ err = rtentry_to_fib_config(cmd, &rt, &cfg);
if (err == 0) {
+ struct fib_table *tb;
+
if (cmd == SIOCDELRT) {
- struct fib_table *tb = fib_get_table(req.rtm.rtm_table);
- err = -ESRCH;
+ tb = fib_get_table(cfg.fc_table);
if (tb)
- err = tb->tb_delete(tb, &req.rtm, &rta, &req.nlh, NULL);
+ err = tb->tb_delete(tb, &cfg);
+ else
+ err = -ESRCH;
} else {
- struct fib_table *tb = fib_new_table(req.rtm.rtm_table);
- err = -ENOBUFS;
+ tb = fib_new_table(cfg.fc_table);
if (tb)
- err = tb->tb_insert(tb, &req.rtm, &rta, &req.nlh, NULL);
+ err = tb->tb_insert(tb, &cfg);
+ else
+ err = -ENOBUFS;
}
- kfree(rta.rta_mx);
+
+ /* allocated by rtentry_to_fib_config() */
+ kfree(cfg.fc_mx);
}
rtnl_unlock();
return err;
@@ -305,51 +453,134 @@
#endif
-static int inet_check_attr(struct rtmsg *r, struct rtattr **rta)
-{
- int i;
+static struct nla_policy rtm_ipv4_policy[RTA_MAX+1] __read_mostly = {
+ [RTA_DST] = { .type = NLA_U32 },
+ [RTA_SRC] = { .type = NLA_U32 },
+ [RTA_IIF] = { .type = NLA_U32 },
+ [RTA_OIF] = { .type = NLA_U32 },
+ [RTA_GATEWAY] = { .type = NLA_U32 },
+ [RTA_PRIORITY] = { .type = NLA_U32 },
+ [RTA_PREFSRC] = { .type = NLA_U32 },
+ [RTA_METRICS] = { .type = NLA_NESTED },
+ [RTA_MULTIPATH] = { .minlen = sizeof(struct rtnexthop) },
+ [RTA_PROTOINFO] = { .type = NLA_U32 },
+ [RTA_FLOW] = { .type = NLA_U32 },
+ [RTA_MP_ALGO] = { .type = NLA_U32 },
+};
- for (i=1; i<=RTA_MAX; i++, rta++) {
- struct rtattr *attr = *rta;
- if (attr) {
- if (RTA_PAYLOAD(attr) < 4)
- return -EINVAL;
- if (i != RTA_MULTIPATH && i != RTA_METRICS &&
- i != RTA_TABLE)
- *rta = (struct rtattr*)RTA_DATA(attr);
+static int rtm_to_fib_config(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct fib_config *cfg)
+{
+ struct nlattr *attr;
+ int err, remaining;
+ struct rtmsg *rtm;
+
+ err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
+ if (err < 0)
+ goto errout;
+
+ memset(cfg, 0, sizeof(*cfg));
+
+ rtm = nlmsg_data(nlh);
+ cfg->fc_family = rtm->rtm_family;
+ cfg->fc_dst_len = rtm->rtm_dst_len;
+ cfg->fc_src_len = rtm->rtm_src_len;
+ cfg->fc_tos = rtm->rtm_tos;
+ cfg->fc_table = rtm->rtm_table;
+ cfg->fc_protocol = rtm->rtm_protocol;
+ cfg->fc_scope = rtm->rtm_scope;
+ cfg->fc_type = rtm->rtm_type;
+ cfg->fc_flags = rtm->rtm_flags;
+ cfg->fc_nlflags = nlh->nlmsg_flags;
+
+ cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
+ cfg->fc_nlinfo.nlh = nlh;
+
+ nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
+ switch (attr->nla_type) {
+ case RTA_DST:
+ cfg->fc_dst = nla_get_u32(attr);
+ break;
+ case RTA_SRC:
+ cfg->fc_src = nla_get_u32(attr);
+ break;
+ case RTA_OIF:
+ cfg->fc_oif = nla_get_u32(attr);
+ break;
+ case RTA_GATEWAY:
+ cfg->fc_gw = nla_get_u32(attr);
+ break;
+ case RTA_PRIORITY:
+ cfg->fc_priority = nla_get_u32(attr);
+ break;
+ case RTA_PREFSRC:
+ cfg->fc_prefsrc = nla_get_u32(attr);
+ break;
+ case RTA_METRICS:
+ cfg->fc_mx = nla_data(attr);
+ cfg->fc_mx_len = nla_len(attr);
+ break;
+ case RTA_MULTIPATH:
+ cfg->fc_mp = nla_data(attr);
+ cfg->fc_mp_len = nla_len(attr);
+ break;
+ case RTA_FLOW:
+ cfg->fc_flow = nla_get_u32(attr);
+ break;
+ case RTA_MP_ALGO:
+ cfg->fc_mp_alg = nla_get_u32(attr);
+ break;
+ case RTA_TABLE:
+ cfg->fc_table = nla_get_u32(attr);
+ break;
}
}
+
return 0;
+errout:
+ return err;
}
int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
- struct fib_table * tb;
- struct rtattr **rta = arg;
- struct rtmsg *r = NLMSG_DATA(nlh);
+ struct fib_config cfg;
+ struct fib_table *tb;
+ int err;
- if (inet_check_attr(r, rta))
- return -EINVAL;
+ err = rtm_to_fib_config(skb, nlh, &cfg);
+ if (err < 0)
+ goto errout;
- tb = fib_get_table(rtm_get_table(rta, r->rtm_table));
- if (tb)
- return tb->tb_delete(tb, r, (struct kern_rta*)rta, nlh, &NETLINK_CB(skb));
- return -ESRCH;
+ tb = fib_get_table(cfg.fc_table);
+ if (tb == NULL) {
+ err = -ESRCH;
+ goto errout;
+ }
+
+ err = tb->tb_delete(tb, &cfg);
+errout:
+ return err;
}
int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
- struct fib_table * tb;
- struct rtattr **rta = arg;
- struct rtmsg *r = NLMSG_DATA(nlh);
+ struct fib_config cfg;
+ struct fib_table *tb;
+ int err;
- if (inet_check_attr(r, rta))
- return -EINVAL;
+ err = rtm_to_fib_config(skb, nlh, &cfg);
+ if (err < 0)
+ goto errout;
- tb = fib_new_table(rtm_get_table(rta, r->rtm_table));
- if (tb)
- return tb->tb_insert(tb, r, (struct kern_rta*)rta, nlh, &NETLINK_CB(skb));
- return -ENOBUFS;
+ tb = fib_new_table(cfg.fc_table);
+ if (tb == NULL) {
+ err = -ENOBUFS;
+ goto errout;
+ }
+
+ err = tb->tb_insert(tb, &cfg);
+errout:
+ return err;
}
int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
@@ -396,17 +627,19 @@
only when netlink is already locked.
*/
-static void fib_magic(int cmd, int type, u32 dst, int dst_len, struct in_ifaddr *ifa)
+static void fib_magic(int cmd, int type, u32 dst, int dst_len,
+ struct in_ifaddr *ifa)
{
- struct fib_table * tb;
- struct {
- struct nlmsghdr nlh;
- struct rtmsg rtm;
- } req;
- struct kern_rta rta;
-
- memset(&req.rtm, 0, sizeof(req.rtm));
- memset(&rta, 0, sizeof(rta));
+ struct fib_table *tb;
+ struct fib_config cfg = {
+ .fc_protocol = RTPROT_KERNEL,
+ .fc_type = type,
+ .fc_dst = dst,
+ .fc_dst_len = dst_len,
+ .fc_prefsrc = ifa->ifa_local,
+ .fc_oif = ifa->ifa_dev->dev->ifindex,
+ .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
+ };
if (type == RTN_UNICAST)
tb = fib_new_table(RT_TABLE_MAIN);
@@ -416,26 +649,17 @@
if (tb == NULL)
return;
- req.nlh.nlmsg_len = sizeof(req);
- req.nlh.nlmsg_type = cmd;
- req.nlh.nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE|NLM_F_APPEND;
- req.nlh.nlmsg_pid = 0;
- req.nlh.nlmsg_seq = 0;
+ cfg.fc_table = tb->tb_id;
- req.rtm.rtm_dst_len = dst_len;
- req.rtm.rtm_table = tb->tb_id;
- req.rtm.rtm_protocol = RTPROT_KERNEL;
- req.rtm.rtm_scope = (type != RTN_LOCAL ? RT_SCOPE_LINK : RT_SCOPE_HOST);
- req.rtm.rtm_type = type;
-
- rta.rta_dst = &dst;
- rta.rta_prefsrc = &ifa->ifa_local;
- rta.rta_oif = &ifa->ifa_dev->dev->ifindex;
+ if (type != RTN_LOCAL)
+ cfg.fc_scope = RT_SCOPE_LINK;
+ else
+ cfg.fc_scope = RT_SCOPE_HOST;
if (cmd == RTM_NEWROUTE)
- tb->tb_insert(tb, &req.rtm, &rta, &req.nlh, NULL);
+ tb->tb_insert(tb, &cfg);
else
- tb->tb_delete(tb, &req.rtm, &rta, &req.nlh, NULL);
+ tb->tb_delete(tb, &cfg);
}
void fib_add_ifaddr(struct in_ifaddr *ifa)