Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2018-05-17

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Provide a new BPF helper for doing a FIB and neighbor lookup
   in the kernel tables from an XDP or tc BPF program. The helper
   provides a fast-path for forwarding packets. The API supports
   IPv4, IPv6 and MPLS protocols, but currently IPv4 and IPv6 are
   implemented in this initial work, from David (Ahern).

2) Just a tiny diff but huge feature enabled for nfp driver by
   extending the BPF offload beyond a pure host processing offload.
   Offloaded XDP programs are allowed to set the RX queue index and
   thus opening the door for defining a fully programmable RSS/n-tuple
   filter replacement. Once BPF decided on a queue already, the device
   data-path will skip the conventional RSS processing completely,
   from Jakub.

3) The original sockmap implementation was array based similar to
   devmap. However unlike devmap where an ifindex has a 1:1 mapping
   into the map there are use cases with sockets that need to be
   referenced using longer keys. Hence, sockhash map is added reusing
   as much of the sockmap code as possible, from John.

4) Introduce BTF ID. The ID is allocatd through an IDR similar as
   with BPF maps and progs. It also makes BTF accessible to user
   space via BPF_BTF_GET_FD_BY_ID and adds exposure of the BTF data
   through BPF_OBJ_GET_INFO_BY_FD, from Martin.

5) Enable BPF stackmap with build_id also in NMI context. Due to the
   up_read() of current->mm->mmap_sem build_id cannot be parsed.
   This work defers the up_read() via a per-cpu irq_work so that
   at least limited support can be enabled, from Song.

6) Various BPF JIT follow-up cleanups and fixups after the LD_ABS/LD_IND
   JIT conversion as well as implementation of an optimized 32/64 bit
   immediate load in the arm64 JIT that allows to reduce the number of
   emitted instructions; in case of tested real-world programs they
   were shrinking by three percent, from Daniel.

7) Add ifindex parameter to the libbpf loader in order to enable
   BPF offload support. Right now only iproute2 can load offloaded
   BPF and this will also enable libbpf for direct integration into
   other applications, from David (Beckett).

8) Convert the plain text documentation under Documentation/bpf/ into
   RST format since this is the appropriate standard the kernel is
   moving to for all documentation. Also add an overview README.rst,
   from Jesper.

9) Add __printf verification attribute to the bpf_verifier_vlog()
   helper. Though it uses va_list we can still allow gcc to check
   the format string, from Mathieu.

10) Fix a bash reference in the BPF selftest's Makefile. The '|& ...'
    is a bash 4.0+ feature which is not guaranteed to be available
    when calling out to shell, therefore use a more portable variant,
    from Joe.

11) Fix a 64 bit division in xdp_umem_reg() by using div_u64()
    instead of relying on the gcc built-in, from Björn.

12) Fix a sock hashmap kmalloc warning reported by syzbot when an
    overly large key size is used in hashmap then causing overflows
    in htab->elem_size. Reject bogus attr->key_size early in the
    sock_hash_alloc(), from Yonghong.

13) Ensure in BPF selftests when urandom_read is being linked that
    --build-id is always enabled so that test_stacktrace_build_id[_nmi]
    won't be failing, from Alexei.

14) Add bitsperlong.h as well as errno.h uapi headers into the tools
    header infrastructure which point to one of the arch specific
    uapi headers. This was needed in order to fix a build error on
    some systems for the BPF selftests, from Sirio.

15) Allow for short options to be used in the xdp_monitor BPF sample
    code. And also a bpf.h tools uapi header sync in order to fix a
    selftest build failure. Both from Prashant.

16) More formally clarify the meaning of ID in the direct packet access
    section of the BPF documentation, from Wang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 141 insertions, 1 deletions

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 93d5a4eeec2a..d94d333a8225 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -96,6 +96,7 @@ enum bpf_cmd {
         BPF_PROG_QUERY,
         BPF_RAW_TRACEPOINT_OPEN,
         BPF_BTF_LOAD,
+        BPF_BTF_GET_FD_BY_ID,
 };
 
 enum bpf_map_type {
@@ -117,6 +118,7 @@ enum bpf_map_type {
         BPF_MAP_TYPE_SOCKMAP,
         BPF_MAP_TYPE_CPUMAP,
         BPF_MAP_TYPE_XSKMAP,
+        BPF_MAP_TYPE_SOCKHASH,
 };
 
 enum bpf_prog_type {
@@ -344,6 +346,7 @@ union bpf_attr {
                         __u32           start_id;
                         __u32           prog_id;
                         __u32           map_id;
+                        __u32           btf_id;
                 };
                 __u32           next_id;
                 __u32           open_flags;
@@ -1826,6 +1829,79 @@ union bpf_attr {
  *      Return
  *              0 on success, or a negative error in case of failure.
  *
+ * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags)
+ *      Description
+ *              Do FIB lookup in kernel tables using parameters in *params*.
+ *              If lookup is successful and result shows packet is to be
+ *              forwarded, the neighbor tables are searched for the nexthop.
+ *              If successful (ie., FIB lookup shows forwarding and nexthop
+ *              is resolved), the nexthop address is returned in ipv4_dst,
+ *              ipv6_dst or mpls_out based on family, smac is set to mac
+ *              address of egress device, dmac is set to nexthop mac address,
+ *              rt_metric is set to metric from route.
+ *
+ *             *plen* argument is the size of the passed in struct.
+ *             *flags* argument can be one or more BPF_FIB_LOOKUP_ flags:
+ *
+ *             **BPF_FIB_LOOKUP_DIRECT** means do a direct table lookup vs
+ *             full lookup using FIB rules
+ *             **BPF_FIB_LOOKUP_OUTPUT** means do lookup from an egress
+ *             perspective (default is ingress)
+ *
+ *             *ctx* is either **struct xdp_md** for XDP programs or
+ *             **struct sk_buff** tc cls_act programs.
+ *
+ *     Return
+ *             Egress device index on success, 0 if packet needs to continue
+ *             up the stack for further processing or a negative error in case
+ *             of failure.
+ *
+ * int bpf_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags)
+ *      Description
+ *              Add an entry to, or update a sockhash *map* referencing sockets.
+ *              The *skops* is used as a new value for the entry associated to
+ *              *key*. *flags* is one of:
+ *
+ *              **BPF_NOEXIST**
+ *                      The entry for *key* must not exist in the map.
+ *              **BPF_EXIST**
+ *                      The entry for *key* must already exist in the map.
+ *              **BPF_ANY**
+ *                      No condition on the existence of the entry for *key*.
+ *
+ *              If the *map* has eBPF programs (parser and verdict), those will
+ *              be inherited by the socket being added. If the socket is
+ *              already attached to eBPF programs, this results in an error.
+ *      Return
+ *              0 on success, or a negative error in case of failure.
+ *
+ * int bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags)
+ *      Description
+ *              This helper is used in programs implementing policies at the
+ *              socket level. If the message *msg* is allowed to pass (i.e. if
+ *              the verdict eBPF program returns **SK_PASS**), redirect it to
+ *              the socket referenced by *map* (of type
+ *              **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
+ *              egress interfaces can be used for redirection. The
+ *              **BPF_F_INGRESS** value in *flags* is used to make the
+ *              distinction (ingress path is selected if the flag is present,
+ *              egress path otherwise). This is the only flag supported for now.
+ *      Return
+ *              **SK_PASS** on success, or **SK_DROP** on error.
+ *
+ * int bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags)
+ *      Description
+ *              This helper is used in programs implementing policies at the
+ *              skb socket level. If the sk_buff *skb* is allowed to pass (i.e.
+ *              if the verdeict eBPF program returns **SK_PASS**), redirect it
+ *              to the socket referenced by *map* (of type
+ *              **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
+ *              egress interfaces can be used for redirection. The
+ *              **BPF_F_INGRESS** value in *flags* is used to make the
+ *              distinction (ingress path is selected if the flag is present,
+ *              egress otherwise). This is the only flag supported for now.
+ *      Return
+ *              **SK_PASS** on success, or **SK_DROP** on error.
  */
 #define __BPF_FUNC_MAPPER(FN)           \
         FN(unspec),                     \
@@ -1896,7 +1972,11 @@ union bpf_attr {
         FN(xdp_adjust_tail),            \
         FN(skb_get_xfrm_state),         \
         FN(get_stack),                  \
-        FN(skb_load_bytes_relative),
+        FN(skb_load_bytes_relative),    \
+        FN(fib_lookup),                 \
+        FN(sock_hash_update),           \
+        FN(msg_redirect_hash),          \
+        FN(sk_redirect_hash),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -2130,6 +2210,15 @@ struct bpf_map_info {
         __u32 ifindex;
         __u64 netns_dev;
         __u64 netns_ino;
+        __u32 btf_id;
+        __u32 btf_key_id;
+        __u32 btf_value_id;
+} __attribute__((aligned(8)));
+
+struct bpf_btf_info {
+        __aligned_u64 btf;
+        __u32 btf_size;
+        __u32 id;
 } __attribute__((aligned(8)));
 
 /* User bpf_sock_addr struct to access socket fields and sockaddr struct passed
@@ -2310,4 +2399,55 @@ struct bpf_raw_tracepoint_args {
         __u64 args[0];
 };
 
+/* DIRECT:  Skip the FIB rules and go to FIB table associated with device
+ * OUTPUT:  Do lookup from egress perspective; default is ingress
+ */
+#define BPF_FIB_LOOKUP_DIRECT  BIT(0)
+#define BPF_FIB_LOOKUP_OUTPUT  BIT(1)
+
+struct bpf_fib_lookup {
+        /* input */
+        __u8    family;   /* network family, AF_INET, AF_INET6, AF_MPLS */
+
+        /* set if lookup is to consider L4 data - e.g., FIB rules */
+        __u8    l4_protocol;
+        __be16  sport;
+        __be16  dport;
+
+        /* total length of packet from network header - used for MTU check */
+        __u16   tot_len;
+        __u32   ifindex;  /* L3 device index for lookup */
+
+        union {
+                /* inputs to lookup */
+                __u8    tos;            /* AF_INET  */
+                __be32  flowlabel;      /* AF_INET6 */
+
+                /* output: metric of fib result */
+                __u32 rt_metric;
+        };
+
+        union {
+                __be32          mpls_in;
+                __be32          ipv4_src;
+                __u32           ipv6_src[4];  /* in6_addr; network order */
+        };
+
+        /* input to bpf_fib_lookup, *dst is destination address.
+         * output: bpf_fib_lookup sets to gateway address
+         */
+        union {
+                /* return for MPLS lookups */
+                __be32          mpls_out[4];  /* support up to 4 labels */
+                __be32          ipv4_dst;
+                __u32           ipv6_dst[4];  /* in6_addr; network order */
+        };
+
+        /* output */
+        __be16  h_vlan_proto;
+        __be16  h_vlan_TCI;
+        __u8    smac[6];     /* ETH_ALEN */
+        __u8    dmac[6];     /* ETH_ALEN */
+};
+
 #endif /* _UAPI__LINUX_BPF_H__ */