net: fib_rules: Add new attribute to set protocol

For ages iproute2 has used `struct rtmsg` as the ancillary header for
FIB rules and in the process set the protocol value to RTPROT_BOOT.
Until ca56209a66 ("net: Allow a rule to track originating protocol")
the kernel rules code ignored the protocol value sent from userspace
and always returned 0 in notifications. To avoid incompatibility with
existing iproute2, send the protocol as a new attribute.

Fixes: cac56209a66 ("net: Allow a rule to track originating protocol")
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 951a4b4..9ce0182 100644 (file)
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -1145,6 +1145,7 @@ static inline size_t vrf_fib_rule_nl_size(void)
        sz  = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
        sz += nla_total_size(sizeof(u8));       /* FRA_L3MDEV */
        sz += nla_total_size(sizeof(u32));      /* FRA_PRIORITY */
+       sz += nla_total_size(sizeof(u8));       /* FRA_PROTOCOL */
 
        return sz;
 }
@@ -1174,7 +1175,9 @@ static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
        memset(frh, 0, sizeof(*frh));
        frh->family = family;
        frh->action = FR_ACT_TO_TBL;
-       frh->proto = RTPROT_KERNEL;
+
+       if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
+               goto nla_put_failure;
 
        if (nla_put_u8(skb, FRA_L3MDEV, 1))
                goto nla_put_failure;

diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index b166ef0..b3d2162 100644 (file)
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -109,7 +109,8 @@ struct fib_rule_notifier_info {
        [FRA_SUPPRESS_IFGROUP] = { .type = NLA_U32 }, \
        [FRA_GOTO]      = { .type = NLA_U32 }, \
        [FRA_L3MDEV]    = { .type = NLA_U8 }, \
-       [FRA_UID_RANGE] = { .len = sizeof(struct fib_rule_uid_range) }
+       [FRA_UID_RANGE] = { .len = sizeof(struct fib_rule_uid_range) }, \
+       [FRA_PROTOCOL]  = { .type = NLA_U8 }
 
 static inline void fib_rule_get(struct fib_rule *rule)
 {

diff --git a/include/uapi/linux/fib_rules.h b/include/uapi/linux/fib_rules.h
index 9255391..77d90ae 100644 (file)
--- a/include/uapi/linux/fib_rules.h
+++ b/include/uapi/linux/fib_rules.h
@@ -23,8 +23,8 @@ struct fib_rule_hdr {
        __u8            tos;
 
        __u8            table;
-       __u8            proto;
-       __u8            res1;   /* reserved */
+       __u8            res1;   /* reserved */
+       __u8            res2;   /* reserved */
        __u8            action;
 
        __u32           flags;
@@ -58,6 +58,7 @@ enum {
        FRA_PAD,
        FRA_L3MDEV,     /* iif or oif is l3mdev goto its table */
        FRA_UID_RANGE,  /* UID range */
+       FRA_PROTOCOL,   /* Originator of the rule */
        __FRA_MAX
 };
 

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 88298f1..a6aea80 100644 (file)
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -466,11 +466,13 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
        }
        refcount_set(&rule->refcnt, 1);
        rule->fr_net = net;
-       rule->proto = frh->proto;
 
        rule->pref = tb[FRA_PRIORITY] ? nla_get_u32(tb[FRA_PRIORITY])
                                      : fib_default_rule_pref(ops);
 
+       rule->proto = tb[FRA_PROTOCOL] ?
+               nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC;
+
        if (tb[FRA_IIFNAME]) {
                struct net_device *dev;
 
@@ -666,7 +668,8 @@ int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
        }
 
        list_for_each_entry(rule, &ops->rules_list, list) {
-               if (frh->proto && (frh->proto != rule->proto))
+               if (tb[FRA_PROTOCOL] &&
+                   (rule->proto != nla_get_u8(tb[FRA_PROTOCOL])))
                        continue;
 
                if (frh->action && (frh->action != rule->action))
@@ -786,7 +789,8 @@ static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
                         + nla_total_size(4) /* FRA_FWMARK */
                         + nla_total_size(4) /* FRA_FWMASK */
                         + nla_total_size_64bit(8) /* FRA_TUN_ID */
-                        + nla_total_size(sizeof(struct fib_kuid_range));
+                        + nla_total_size(sizeof(struct fib_kuid_range))
+                        + nla_total_size(1); /* FRA_PROTOCOL */
 
        if (ops->nlmsg_payload)
                payload += ops->nlmsg_payload(rule);
@@ -813,9 +817,12 @@ static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
        if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
                goto nla_put_failure;
        frh->res1 = 0;
+       frh->res2 = 0;
        frh->action = rule->action;
        frh->flags = rule->flags;
-       frh->proto = rule->proto;
+
+       if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
+               goto nla_put_failure;
 
        if (rule->action == FR_ACT_GOTO &&
            rcu_access_pointer(rule->ctarget) == NULL)