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-rw-r--r--include/linux/bpf-cgroup.h31
-rw-r--r--include/net/addrconf.h7
-rw-r--r--include/net/sock.h3
-rw-r--r--include/net/udp.h1
-rw-r--r--include/uapi/linux/bpf.h12
-rw-r--r--kernel/bpf/syscall.c8
-rw-r--r--net/core/filter.c57
-rw-r--r--net/ipv4/af_inet.c13
-rw-r--r--net/ipv4/tcp_ipv4.c16
-rw-r--r--net/ipv4/udp.c14
-rw-r--r--net/ipv6/af_inet6.c5
-rw-r--r--net/ipv6/tcp_ipv6.c16
-rw-r--r--net/ipv6/udp.c20
13 files changed, 202 insertions, 1 deletions
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 67dc4a6471ad..c6ab295e6dcb 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -116,12 +116,38 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
__ret; \
})
+#define BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, type) \
+({ \
+ int __ret = 0; \
+ if (cgroup_bpf_enabled) { \
+ lock_sock(sk); \
+ __ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, type); \
+ release_sock(sk); \
+ } \
+ __ret; \
+})
+
#define BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr) \
BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET4_BIND)
#define BPF_CGROUP_RUN_PROG_INET6_BIND(sk, uaddr) \
BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET6_BIND)
+#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (cgroup_bpf_enabled && \
+ sk->sk_prot->pre_connect)
+
+#define BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr) \
+ BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET4_CONNECT)
+
+#define BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr) \
+ BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET6_CONNECT)
+
+#define BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr) \
+ BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET4_CONNECT)
+
+#define BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr) \
+ BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET6_CONNECT)
+
#define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) \
({ \
int __ret = 0; \
@@ -151,11 +177,16 @@ struct cgroup_bpf {};
static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
static inline int cgroup_bpf_inherit(struct cgroup *cgrp) { return 0; }
+#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (0)
#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk,skb) ({ 0; })
#define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk,skb) ({ 0; })
#define BPF_CGROUP_RUN_PROG_INET_SOCK(sk) ({ 0; })
#define BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr) ({ 0; })
#define BPF_CGROUP_RUN_PROG_INET6_BIND(sk, uaddr) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr) ({ 0; })
#define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) ({ 0; })
#define BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type,major,minor,access) ({ 0; })
diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index 132e5b95167a..378d601258be 100644
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -231,6 +231,13 @@ struct ipv6_stub {
};
extern const struct ipv6_stub *ipv6_stub __read_mostly;
+/* A stub used by bpf helpers. Similarly ugly as ipv6_stub */
+struct ipv6_bpf_stub {
+ int (*inet6_bind)(struct sock *sk, struct sockaddr *uaddr, int addr_len,
+ bool force_bind_address_no_port, bool with_lock);
+};
+extern const struct ipv6_bpf_stub *ipv6_bpf_stub __read_mostly;
+
/*
* identify MLD packets for MLD filter exceptions
*/
diff --git a/include/net/sock.h b/include/net/sock.h
index b8ff435fa96e..49bd2c1796b0 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1026,6 +1026,9 @@ static inline void sk_prot_clear_nulls(struct sock *sk, int size)
struct proto {
void (*close)(struct sock *sk,
long timeout);
+ int (*pre_connect)(struct sock *sk,
+ struct sockaddr *uaddr,
+ int addr_len);
int (*connect)(struct sock *sk,
struct sockaddr *uaddr,
int addr_len);
diff --git a/include/net/udp.h b/include/net/udp.h
index 850a8e581cce..0676b272f6ac 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -273,6 +273,7 @@ void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);
int udp_rcv(struct sk_buff *skb);
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
int udp_init_sock(struct sock *sk);
+int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
int __udp_disconnect(struct sock *sk, int flags);
int udp_disconnect(struct sock *sk, int flags);
__poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index ce3e69e3c793..77afaf1ba556 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -150,6 +150,8 @@ enum bpf_attach_type {
BPF_SK_MSG_VERDICT,
BPF_CGROUP_INET4_BIND,
BPF_CGROUP_INET6_BIND,
+ BPF_CGROUP_INET4_CONNECT,
+ BPF_CGROUP_INET6_CONNECT,
__MAX_BPF_ATTACH_TYPE
};
@@ -744,6 +746,13 @@ union bpf_attr {
* @flags: reserved for future use
* Return: SK_PASS
*
+ * int bpf_bind(ctx, addr, addr_len)
+ * Bind socket to address. Only binding to IP is supported, no port can be
+ * set in addr.
+ * @ctx: pointer to context of type bpf_sock_addr
+ * @addr: pointer to struct sockaddr to bind socket to
+ * @addr_len: length of sockaddr structure
+ * Return: 0 on success or negative error code
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -809,7 +818,8 @@ union bpf_attr {
FN(msg_redirect_map), \
FN(msg_apply_bytes), \
FN(msg_cork_bytes), \
- FN(msg_pull_data),
+ FN(msg_pull_data), \
+ FN(bind),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 2cad66a4cacb..cf1b29bc0ab8 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1180,6 +1180,8 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
switch (expected_attach_type) {
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
+ case BPF_CGROUP_INET4_CONNECT:
+ case BPF_CGROUP_INET6_CONNECT:
return 0;
default:
return -EINVAL;
@@ -1491,6 +1493,8 @@ static int bpf_prog_attach(const union bpf_attr *attr)
break;
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
+ case BPF_CGROUP_INET4_CONNECT:
+ case BPF_CGROUP_INET6_CONNECT:
ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
break;
case BPF_CGROUP_SOCK_OPS:
@@ -1557,6 +1561,8 @@ static int bpf_prog_detach(const union bpf_attr *attr)
break;
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
+ case BPF_CGROUP_INET4_CONNECT:
+ case BPF_CGROUP_INET6_CONNECT:
ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
break;
case BPF_CGROUP_SOCK_OPS:
@@ -1610,6 +1616,8 @@ static int bpf_prog_query(const union bpf_attr *attr,
case BPF_CGROUP_INET_SOCK_CREATE:
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
+ case BPF_CGROUP_INET4_CONNECT:
+ case BPF_CGROUP_INET6_CONNECT:
case BPF_CGROUP_SOCK_OPS:
case BPF_CGROUP_DEVICE:
break;
diff --git a/net/core/filter.c b/net/core/filter.c
index c08e5b121558..bdb9cadd4d27 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -33,6 +33,7 @@
#include <linux/if_packet.h>
#include <linux/if_arp.h>
#include <linux/gfp.h>
+#include <net/inet_common.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/netlink.h>
@@ -3656,6 +3657,52 @@ static const struct bpf_func_proto bpf_sock_ops_cb_flags_set_proto = {
.arg2_type = ARG_ANYTHING,
};
+const struct ipv6_bpf_stub *ipv6_bpf_stub __read_mostly;
+EXPORT_SYMBOL_GPL(ipv6_bpf_stub);
+
+BPF_CALL_3(bpf_bind, struct bpf_sock_addr_kern *, ctx, struct sockaddr *, addr,
+ int, addr_len)
+{
+#ifdef CONFIG_INET
+ struct sock *sk = ctx->sk;
+ int err;
+
+ /* Binding to port can be expensive so it's prohibited in the helper.
+ * Only binding to IP is supported.
+ */
+ err = -EINVAL;
+ if (addr->sa_family == AF_INET) {
+ if (addr_len < sizeof(struct sockaddr_in))
+ return err;
+ if (((struct sockaddr_in *)addr)->sin_port != htons(0))
+ return err;
+ return __inet_bind(sk, addr, addr_len, true, false);
+#if IS_ENABLED(CONFIG_IPV6)
+ } else if (addr->sa_family == AF_INET6) {
+ if (addr_len < SIN6_LEN_RFC2133)
+ return err;
+ if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
+ return err;
+ /* ipv6_bpf_stub cannot be NULL, since it's called from
+ * bpf_cgroup_inet6_connect hook and ipv6 is already loaded
+ */
+ return ipv6_bpf_stub->inet6_bind(sk, addr, addr_len, true, false);
+#endif /* CONFIG_IPV6 */
+ }
+#endif /* CONFIG_INET */
+
+ return -EAFNOSUPPORT;
+}
+
+static const struct bpf_func_proto bpf_bind_proto = {
+ .func = bpf_bind,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+};
+
static const struct bpf_func_proto *
bpf_base_func_proto(enum bpf_func_id func_id)
{
@@ -3707,6 +3754,14 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
*/
case BPF_FUNC_get_current_uid_gid:
return &bpf_get_current_uid_gid_proto;
+ case BPF_FUNC_bind:
+ switch (prog->expected_attach_type) {
+ case BPF_CGROUP_INET4_CONNECT:
+ case BPF_CGROUP_INET6_CONNECT:
+ return &bpf_bind_proto;
+ default:
+ return NULL;
+ }
default:
return bpf_base_func_proto(func_id);
}
@@ -4213,6 +4268,7 @@ static bool sock_addr_is_valid_access(int off, int size,
case bpf_ctx_range(struct bpf_sock_addr, user_ip4):
switch (prog->expected_attach_type) {
case BPF_CGROUP_INET4_BIND:
+ case BPF_CGROUP_INET4_CONNECT:
break;
default:
return false;
@@ -4221,6 +4277,7 @@ static bool sock_addr_is_valid_access(int off, int size,
case bpf_ctx_range_till(struct bpf_sock_addr, user_ip6[0], user_ip6[3]):
switch (prog->expected_attach_type) {
case BPF_CGROUP_INET6_BIND:
+ case BPF_CGROUP_INET6_CONNECT:
break;
default:
return false;
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index e203a39d6988..488fe26ac8e5 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -547,12 +547,19 @@ int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
int addr_len, int flags)
{
struct sock *sk = sock->sk;
+ int err;
if (addr_len < sizeof(uaddr->sa_family))
return -EINVAL;
if (uaddr->sa_family == AF_UNSPEC)
return sk->sk_prot->disconnect(sk, flags);
+ if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
+ err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
+ if (err)
+ return err;
+ }
+
if (!inet_sk(sk)->inet_num && inet_autobind(sk))
return -EAGAIN;
return sk->sk_prot->connect(sk, uaddr, addr_len);
@@ -633,6 +640,12 @@ int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
if (sk->sk_state != TCP_CLOSE)
goto out;
+ if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
+ err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
+ if (err)
+ goto out;
+ }
+
err = sk->sk_prot->connect(sk, uaddr, addr_len);
if (err < 0)
goto out;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 2c6aec2643e8..3c11d992d784 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -140,6 +140,21 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
}
EXPORT_SYMBOL_GPL(tcp_twsk_unique);
+static int tcp_v4_pre_connect(struct sock *sk, struct sockaddr *uaddr,
+ int addr_len)
+{
+ /* This check is replicated from tcp_v4_connect() and intended to
+ * prevent BPF program called below from accessing bytes that are out
+ * of the bound specified by user in addr_len.
+ */
+ if (addr_len < sizeof(struct sockaddr_in))
+ return -EINVAL;
+
+ sock_owned_by_me(sk);
+
+ return BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr);
+}
+
/* This will initiate an outgoing connection. */
int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
@@ -2409,6 +2424,7 @@ struct proto tcp_prot = {
.name = "TCP",
.owner = THIS_MODULE,
.close = tcp_close,
+ .pre_connect = tcp_v4_pre_connect,
.connect = tcp_v4_connect,
.disconnect = tcp_disconnect,
.accept = inet_csk_accept,
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 908fc02fb4f8..9c6c77fec963 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1658,6 +1658,19 @@ csum_copy_err:
goto try_again;
}
+int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+ /* This check is replicated from __ip4_datagram_connect() and
+ * intended to prevent BPF program called below from accessing bytes
+ * that are out of the bound specified by user in addr_len.
+ */
+ if (addr_len < sizeof(struct sockaddr_in))
+ return -EINVAL;
+
+ return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr);
+}
+EXPORT_SYMBOL(udp_pre_connect);
+
int __udp_disconnect(struct sock *sk, int flags)
{
struct inet_sock *inet = inet_sk(sk);
@@ -2530,6 +2543,7 @@ struct proto udp_prot = {
.name = "UDP",
.owner = THIS_MODULE,
.close = udp_lib_close,
+ .pre_connect = udp_pre_connect,
.connect = ip4_datagram_connect,
.disconnect = udp_disconnect,
.ioctl = udp_ioctl,
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 13110bee5c14..566cec0e0a44 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -887,6 +887,10 @@ static const struct ipv6_stub ipv6_stub_impl = {
.nd_tbl = &nd_tbl,
};
+static const struct ipv6_bpf_stub ipv6_bpf_stub_impl = {
+ .inet6_bind = __inet6_bind,
+};
+
static int __init inet6_init(void)
{
struct list_head *r;
@@ -1043,6 +1047,7 @@ static int __init inet6_init(void)
/* ensure that ipv6 stubs are visible only after ipv6 is ready */
wmb();
ipv6_stub = &ipv6_stub_impl;
+ ipv6_bpf_stub = &ipv6_bpf_stub_impl;
out:
return err;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 5425d7b100ee..6469b741cf5a 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -117,6 +117,21 @@ static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
ipv6_hdr(skb)->saddr.s6_addr32);
}
+static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
+ int addr_len)
+{
+ /* This check is replicated from tcp_v6_connect() and intended to
+ * prevent BPF program called below from accessing bytes that are out
+ * of the bound specified by user in addr_len.
+ */
+ if (addr_len < SIN6_LEN_RFC2133)
+ return -EINVAL;
+
+ sock_owned_by_me(sk);
+
+ return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr);
+}
+
static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
int addr_len)
{
@@ -1925,6 +1940,7 @@ struct proto tcpv6_prot = {
.name = "TCPv6",
.owner = THIS_MODULE,
.close = tcp_close,
+ .pre_connect = tcp_v6_pre_connect,
.connect = tcp_v6_connect,
.disconnect = tcp_disconnect,
.accept = inet_csk_accept,
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index ad30f5e31969..6861ed479469 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -957,6 +957,25 @@ static void udp_v6_flush_pending_frames(struct sock *sk)
}
}
+static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
+ int addr_len)
+{
+ /* The following checks are replicated from __ip6_datagram_connect()
+ * and intended to prevent BPF program called below from accessing
+ * bytes that are out of the bound specified by user in addr_len.
+ */
+ if (uaddr->sa_family == AF_INET) {
+ if (__ipv6_only_sock(sk))
+ return -EAFNOSUPPORT;
+ return udp_pre_connect(sk, uaddr, addr_len);
+ }
+
+ if (addr_len < SIN6_LEN_RFC2133)
+ return -EINVAL;
+
+ return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
+}
+
/**
* udp6_hwcsum_outgoing - handle outgoing HW checksumming
* @sk: socket we are sending on
@@ -1512,6 +1531,7 @@ struct proto udpv6_prot = {
.name = "UDPv6",
.owner = THIS_MODULE,
.close = udp_lib_close,
+ .pre_connect = udpv6_pre_connect,
.connect = ip6_datagram_connect,
.disconnect = udp_disconnect,
.ioctl = udp_ioctl,
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-04 04:18:08 +0000