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-rw-r--r--net/core/filter.c121
-rw-r--r--net/core/sock.c29
-rw-r--r--net/core/sock_reuseport.c88
3 files changed, 211 insertions, 27 deletions
diff --git a/net/core/filter.c b/net/core/filter.c
index c770196ae8d5..35e6fed28709 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -50,6 +50,7 @@
#include <net/cls_cgroup.h>
#include <net/dst_metadata.h>
#include <net/dst.h>
+#include <net/sock_reuseport.h>
/**
* sk_filter - run a packet through a socket filter
@@ -1167,17 +1168,32 @@ static int __sk_attach_prog(struct bpf_prog *prog, struct sock *sk)
return 0;
}
-/**
- * sk_attach_filter - attach a socket filter
- * @fprog: the filter program
- * @sk: the socket to use
- *
- * Attach the user's filter code. We first run some sanity checks on
- * it to make sure it does not explode on us later. If an error
- * occurs or there is insufficient memory for the filter a negative
- * errno code is returned. On success the return is zero.
- */
-int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
+static int __reuseport_attach_prog(struct bpf_prog *prog, struct sock *sk)
+{
+ struct bpf_prog *old_prog;
+ int err;
+
+ if (bpf_prog_size(prog->len) > sysctl_optmem_max)
+ return -ENOMEM;
+
+ if (sk_unhashed(sk)) {
+ err = reuseport_alloc(sk);
+ if (err)
+ return err;
+ } else if (!rcu_access_pointer(sk->sk_reuseport_cb)) {
+ /* The socket wasn't bound with SO_REUSEPORT */
+ return -EINVAL;
+ }
+
+ old_prog = reuseport_attach_prog(sk, prog);
+ if (old_prog)
+ bpf_prog_destroy(old_prog);
+
+ return 0;
+}
+
+static
+struct bpf_prog *__get_filter(struct sock_fprog *fprog, struct sock *sk)
{
unsigned int fsize = bpf_classic_proglen(fprog);
unsigned int bpf_fsize = bpf_prog_size(fprog->len);
@@ -1185,19 +1201,19 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
int err;
if (sock_flag(sk, SOCK_FILTER_LOCKED))
- return -EPERM;
+ return ERR_PTR(-EPERM);
/* Make sure new filter is there and in the right amounts. */
if (fprog->filter == NULL)
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
prog = bpf_prog_alloc(bpf_fsize, 0);
if (!prog)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
if (copy_from_user(prog->insns, fprog->filter, fsize)) {
__bpf_prog_free(prog);
- return -EFAULT;
+ return ERR_PTR(-EFAULT);
}
prog->len = fprog->len;
@@ -1205,13 +1221,30 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
err = bpf_prog_store_orig_filter(prog, fprog);
if (err) {
__bpf_prog_free(prog);
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
}
/* bpf_prepare_filter() already takes care of freeing
* memory in case something goes wrong.
*/
- prog = bpf_prepare_filter(prog, NULL);
+ return bpf_prepare_filter(prog, NULL);
+}
+
+/**
+ * sk_attach_filter - attach a socket filter
+ * @fprog: the filter program
+ * @sk: the socket to use
+ *
+ * Attach the user's filter code. We first run some sanity checks on
+ * it to make sure it does not explode on us later. If an error
+ * occurs or there is insufficient memory for the filter a negative
+ * errno code is returned. On success the return is zero.
+ */
+int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
+{
+ struct bpf_prog *prog = __get_filter(fprog, sk);
+ int err;
+
if (IS_ERR(prog))
return PTR_ERR(prog);
@@ -1225,23 +1258,50 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
}
EXPORT_SYMBOL_GPL(sk_attach_filter);
-int sk_attach_bpf(u32 ufd, struct sock *sk)
+int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk)
{
- struct bpf_prog *prog;
+ struct bpf_prog *prog = __get_filter(fprog, sk);
int err;
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+
+ err = __reuseport_attach_prog(prog, sk);
+ if (err < 0) {
+ __bpf_prog_release(prog);
+ return err;
+ }
+
+ return 0;
+}
+
+static struct bpf_prog *__get_bpf(u32 ufd, struct sock *sk)
+{
+ struct bpf_prog *prog;
+
if (sock_flag(sk, SOCK_FILTER_LOCKED))
- return -EPERM;
+ return ERR_PTR(-EPERM);
prog = bpf_prog_get(ufd);
if (IS_ERR(prog))
- return PTR_ERR(prog);
+ return prog;
if (prog->type != BPF_PROG_TYPE_SOCKET_FILTER) {
bpf_prog_put(prog);
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
}
+ return prog;
+}
+
+int sk_attach_bpf(u32 ufd, struct sock *sk)
+{
+ struct bpf_prog *prog = __get_bpf(ufd, sk);
+ int err;
+
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+
err = __sk_attach_prog(prog, sk);
if (err < 0) {
bpf_prog_put(prog);
@@ -1251,6 +1311,23 @@ int sk_attach_bpf(u32 ufd, struct sock *sk)
return 0;
}
+int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk)
+{
+ struct bpf_prog *prog = __get_bpf(ufd, sk);
+ int err;
+
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+
+ err = __reuseport_attach_prog(prog, sk);
+ if (err < 0) {
+ bpf_prog_put(prog);
+ return err;
+ }
+
+ return 0;
+}
+
#define BPF_RECOMPUTE_CSUM(flags) ((flags) & 1)
#define BPF_LDST_LEN 16U
diff --git a/net/core/sock.c b/net/core/sock.c
index 565bab7baca9..51270238e269 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -134,6 +134,7 @@
#include <linux/sock_diag.h>
#include <linux/filter.h>
+#include <net/sock_reuseport.h>
#include <trace/events/sock.h>
@@ -932,6 +933,32 @@ set_rcvbuf:
}
break;
+ case SO_ATTACH_REUSEPORT_CBPF:
+ ret = -EINVAL;
+ if (optlen == sizeof(struct sock_fprog)) {
+ struct sock_fprog fprog;
+
+ ret = -EFAULT;
+ if (copy_from_user(&fprog, optval, sizeof(fprog)))
+ break;
+
+ ret = sk_reuseport_attach_filter(&fprog, sk);
+ }
+ break;
+
+ case SO_ATTACH_REUSEPORT_EBPF:
+ ret = -EINVAL;
+ if (optlen == sizeof(u32)) {
+ u32 ufd;
+
+ ret = -EFAULT;
+ if (copy_from_user(&ufd, optval, sizeof(ufd)))
+ break;
+
+ ret = sk_reuseport_attach_bpf(ufd, sk);
+ }
+ break;
+
case SO_DETACH_FILTER:
ret = sk_detach_filter(sk);
break;
@@ -1443,6 +1470,8 @@ void sk_destruct(struct sock *sk)
sk_filter_uncharge(sk, filter);
RCU_INIT_POINTER(sk->sk_filter, NULL);
}
+ if (rcu_access_pointer(sk->sk_reuseport_cb))
+ reuseport_detach_sock(sk);
sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
index 963c8d5f3027..ae0969c0fc2e 100644
--- a/net/core/sock_reuseport.c
+++ b/net/core/sock_reuseport.c
@@ -1,10 +1,12 @@
/*
* To speed up listener socket lookup, create an array to store all sockets
* listening on the same port. This allows a decision to be made after finding
- * the first socket.
+ * the first socket. An optional BPF program can also be configured for
+ * selecting the socket index from the array of available sockets.
*/
#include <net/sock_reuseport.h>
+#include <linux/bpf.h>
#include <linux/rcupdate.h>
#define INIT_SOCKS 128
@@ -22,6 +24,7 @@ static struct sock_reuseport *__reuseport_alloc(u16 max_socks)
reuse->max_socks = max_socks;
+ RCU_INIT_POINTER(reuse->prog, NULL);
return reuse;
}
@@ -67,6 +70,7 @@ static struct sock_reuseport *reuseport_grow(struct sock_reuseport *reuse)
more_reuse->max_socks = more_socks_size;
more_reuse->num_socks = reuse->num_socks;
+ more_reuse->prog = reuse->prog;
memcpy(more_reuse->socks, reuse->socks,
reuse->num_socks * sizeof(struct sock *));
@@ -75,6 +79,10 @@ static struct sock_reuseport *reuseport_grow(struct sock_reuseport *reuse)
rcu_assign_pointer(reuse->socks[i]->sk_reuseport_cb,
more_reuse);
+ /* Note: we use kfree_rcu here instead of reuseport_free_rcu so
+ * that reuse and more_reuse can temporarily share a reference
+ * to prog.
+ */
kfree_rcu(reuse, rcu);
return more_reuse;
}
@@ -116,6 +124,16 @@ int reuseport_add_sock(struct sock *sk, const struct sock *sk2)
}
EXPORT_SYMBOL(reuseport_add_sock);
+static void reuseport_free_rcu(struct rcu_head *head)
+{
+ struct sock_reuseport *reuse;
+
+ reuse = container_of(head, struct sock_reuseport, rcu);
+ if (reuse->prog)
+ bpf_prog_destroy(reuse->prog);
+ kfree(reuse);
+}
+
void reuseport_detach_sock(struct sock *sk)
{
struct sock_reuseport *reuse;
@@ -131,7 +149,7 @@ void reuseport_detach_sock(struct sock *sk)
reuse->socks[i] = reuse->socks[reuse->num_socks - 1];
reuse->num_socks--;
if (reuse->num_socks == 0)
- kfree_rcu(reuse, rcu);
+ call_rcu(&reuse->rcu, reuseport_free_rcu);
break;
}
}
@@ -139,15 +157,53 @@ void reuseport_detach_sock(struct sock *sk)
}
EXPORT_SYMBOL(reuseport_detach_sock);
+static struct sock *run_bpf(struct sock_reuseport *reuse, u16 socks,
+ struct bpf_prog *prog, struct sk_buff *skb,
+ int hdr_len)
+{
+ struct sk_buff *nskb = NULL;
+ u32 index;
+
+ if (skb_shared(skb)) {
+ nskb = skb_clone(skb, GFP_ATOMIC);
+ if (!nskb)
+ return NULL;
+ skb = nskb;
+ }
+
+ /* temporarily advance data past protocol header */
+ if (!pskb_pull(skb, hdr_len)) {
+ consume_skb(nskb);
+ return NULL;
+ }
+ index = bpf_prog_run_save_cb(prog, skb);
+ __skb_push(skb, hdr_len);
+
+ consume_skb(nskb);
+
+ if (index >= socks)
+ return NULL;
+
+ return reuse->socks[index];
+}
+
/**
* reuseport_select_sock - Select a socket from an SO_REUSEPORT group.
* @sk: First socket in the group.
- * @hash: Use this hash to select.
+ * @hash: When no BPF filter is available, use this hash to select.
+ * @skb: skb to run through BPF filter.
+ * @hdr_len: BPF filter expects skb data pointer at payload data. If
+ * the skb does not yet point at the payload, this parameter represents
+ * how far the pointer needs to advance to reach the payload.
* Returns a socket that should receive the packet (or NULL on error).
*/
-struct sock *reuseport_select_sock(struct sock *sk, u32 hash)
+struct sock *reuseport_select_sock(struct sock *sk,
+ u32 hash,
+ struct sk_buff *skb,
+ int hdr_len)
{
struct sock_reuseport *reuse;
+ struct bpf_prog *prog;
struct sock *sk2 = NULL;
u16 socks;
@@ -158,12 +214,16 @@ struct sock *reuseport_select_sock(struct sock *sk, u32 hash)
if (!reuse)
goto out;
+ prog = rcu_dereference(reuse->prog);
socks = READ_ONCE(reuse->num_socks);
if (likely(socks)) {
/* paired with smp_wmb() in reuseport_add_sock() */
smp_rmb();
- sk2 = reuse->socks[reciprocal_scale(hash, socks)];
+ if (prog && skb)
+ sk2 = run_bpf(reuse, socks, prog, skb, hdr_len);
+ else
+ sk2 = reuse->socks[reciprocal_scale(hash, socks)];
}
out:
@@ -171,3 +231,21 @@ out:
return sk2;
}
EXPORT_SYMBOL(reuseport_select_sock);
+
+struct bpf_prog *
+reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog)
+{
+ struct sock_reuseport *reuse;
+ struct bpf_prog *old_prog;
+
+ spin_lock_bh(&reuseport_lock);
+ reuse = rcu_dereference_protected(sk->sk_reuseport_cb,
+ lockdep_is_held(&reuseport_lock));
+ old_prog = rcu_dereference_protected(reuse->prog,
+ lockdep_is_held(&reuseport_lock));
+ rcu_assign_pointer(reuse->prog, prog);
+ spin_unlock_bh(&reuseport_lock);
+
+ return old_prog;
+}
+EXPORT_SYMBOL(reuseport_attach_prog);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-09 19:23:45 +0000