net: core: add UID to flows, rules, and routes

- Define a new FIB rule attributes, FRA_UID_RANGE, to describe a
  range of UIDs.
- Define a RTA_UID attribute for per-UID route lookups and dumps.
- Support passing these attributes to and from userspace via
  rtnetlink. The value INVALID_UID indicates no UID was
  specified.
- Add a UID field to the flow structures.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 20 insertions, 1 deletions

diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index 456e4a6006ab..8dbfdf728cd8 100644
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -8,6 +8,11 @@
 #include <net/flow.h>
 #include <net/rtnetlink.h>
 
+struct fib_kuid_range {
+	kuid_t start;
+	kuid_t end;
+};
+
 struct fib_rule {
 	struct list_head	list;
 	int			iifindex;
@@ -30,6 +35,7 @@ struct fib_rule {
 	int			suppress_prefixlen;
 	char			iifname[IFNAMSIZ];
 	char			oifname[IFNAMSIZ];
+	struct fib_kuid_range	uid_range;
 	struct rcu_head		rcu;
 };
 
@@ -92,7 +98,8 @@ struct fib_rules_ops {
 	[FRA_SUPPRESS_PREFIXLEN] = { .type = NLA_U32 }, \
 	[FRA_SUPPRESS_IFGROUP] = { .type = NLA_U32 }, \
 	[FRA_GOTO]	= { .type = NLA_U32 }, \
-	[FRA_L3MDEV]	= { .type = NLA_U8 }
+	[FRA_L3MDEV]	= { .type = NLA_U8 }, \
+	[FRA_UID_RANGE]	= { .len = sizeof(struct fib_rule_uid_range) }
 
 static inline void fib_rule_get(struct fib_rule *rule)
 {
diff --git a/include/net/flow.h b/include/net/flow.h
index 035aa7716967..51373f3a5e31 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -11,6 +11,7 @@
 #include <linux/in6.h>
 #include <linux/atomic.h>
 #include <net/flow_dissector.h>
+#include <linux/uidgid.h>
 
 /*
  * ifindex generation is per-net namespace, and loopback is
@@ -37,6 +38,7 @@ struct flowi_common {
 #define FLOWI_FLAG_SKIP_NH_OIF		0x04
 	__u32	flowic_secid;
 	struct flowi_tunnel flowic_tun_key;
+	kuid_t  flowic_uid;
 };
 
 union flowi_uli {
@@ -74,6 +76,7 @@ struct flowi4 {
 #define flowi4_flags		__fl_common.flowic_flags
 #define flowi4_secid		__fl_common.flowic_secid
 #define flowi4_tun_key		__fl_common.flowic_tun_key
+#define flowi4_uid		__fl_common.flowic_uid
 
 	/* (saddr,daddr) must be grouped, same order as in IP header */
 	__be32			saddr;
@@ -131,6 +134,7 @@ struct flowi6 {
 #define flowi6_flags		__fl_common.flowic_flags
 #define flowi6_secid		__fl_common.flowic_secid
 #define flowi6_tun_key		__fl_common.flowic_tun_key
+#define flowi6_uid		__fl_common.flowic_uid
 	struct in6_addr		daddr;
 	struct in6_addr		saddr;
 	/* Note: flowi6_tos is encoded in flowlabel, too. */
@@ -176,6 +180,7 @@ struct flowi {
 #define flowi_flags	u.__fl_common.flowic_flags
 #define flowi_secid	u.__fl_common.flowic_secid
 #define flowi_tun_key	u.__fl_common.flowic_tun_key
+#define flowi_uid	u.__fl_common.flowic_uid
 } __attribute__((__aligned__(BITS_PER_LONG/8)));
 
 static inline struct flowi *flowi4_to_flowi(struct flowi4 *fl4)
diff --git a/include/uapi/linux/fib_rules.h b/include/uapi/linux/fib_rules.h
index 14404b3ebb89..bbf02a63a011 100644
--- a/include/uapi/linux/fib_rules.h
+++ b/include/uapi/linux/fib_rules.h
@@ -29,6 +29,11 @@ struct fib_rule_hdr {
 	__u32		flags;
 };
 
+struct fib_rule_uid_range {
+	__u32		start;
+	__u32		end;
+};
+
 enum {
 	FRA_UNSPEC,
 	FRA_DST,	/* destination address */
@@ -51,6 +56,7 @@ enum {
 	FRA_OIFNAME,
 	FRA_PAD,
 	FRA_L3MDEV,	/* iif or oif is l3mdev goto its table */
+	FRA_UID_RANGE,	/* UID range */
 	__FRA_MAX
 };
 
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 5a78be518101..e14377f2ec27 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -318,6 +318,7 @@ enum rtattr_type_t {
 	RTA_ENCAP,
 	RTA_EXPIRES,
 	RTA_PAD,
+	RTA_UID,
 	__RTA_MAX
 };