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| author |   YiFei Zhu <zhuyifei@google.com> | 2022-09-09 00:49:39 +0000 |
|---|---|---|
| committer |   Martin KaFai Lau <martin.lau@kernel.org> | 2022-09-09 10:40:45 -0700 |
| commit | 0ffe2412531e95a309d7f0bfe985fc4ca4d39de8 (patch) | |
| tree | 2c391b0f14d8bdbc1af1726182486400a8151e5a | |
| parent | libbpf: Remove gcc support for bpf_tail_call_static for now (diff) | |
| download | wireguard-linux-0ffe2412531e95a309d7f0bfe985fc4ca4d39de8.tar.xz wireguard-linux-0ffe2412531e95a309d7f0bfe985fc4ca4d39de8.zip | |
bpf: Invoke cgroup/connect{4,6} programs for unprivileged ICMP ping
Usually when a TCP/UDP connection is initiated, we can bind the socket
to a specific IP attached to an interface in a cgroup/connect hook.
But for pings, this is impossible, as the hook is not being called.
This adds the hook invocation to unprivileged ICMP ping (i.e. ping
sockets created with SOCK_DGRAM IPPROTO_ICMP(V6) as opposed to
SOCK_RAW. Logic is mirrored from UDP sockets where the hook is invoked
during pre_connect, after a check for suficiently sized addr_len.
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Link: https://lore.kernel.org/r/5764914c252fad4cd134fb6664c6ede95f409412.1662682323.git.zhuyifei@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
| -rw-r--r-- | net/ipv4/ping.c | 15 | ||||
| -rw-r--r-- | net/ipv6/ping.c | 16 |
2 files changed, 31 insertions, 0 deletions
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index b83c2bd9d722..517042caf6dc 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -33,6 +33,7 @@ #include <linux/skbuff.h> #include <linux/proc_fs.h> #include <linux/export.h> +#include <linux/bpf-cgroup.h> #include <net/sock.h> #include <net/ping.h> #include <net/udp.h> @@ -295,6 +296,19 @@ void ping_close(struct sock *sk, long timeout) } EXPORT_SYMBOL_GPL(ping_close); +static int ping_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); +} + /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, struct sockaddr *uaddr, int addr_len) @@ -1009,6 +1023,7 @@ struct proto ping_prot = { .owner = THIS_MODULE, .init = ping_init_sock, .close = ping_close, + .pre_connect = ping_pre_connect, .connect = ip4_datagram_connect, .disconnect = __udp_disconnect, .setsockopt = ip_setsockopt, diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index 91b840514656..5f2ef8493714 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -20,6 +20,7 @@ #include <net/udp.h> #include <net/transp_v6.h> #include <linux/proc_fs.h> +#include <linux/bpf-cgroup.h> #include <net/ping.h> static void ping_v6_destroy(struct sock *sk) @@ -49,6 +50,20 @@ static int dummy_ipv6_chk_addr(struct net *net, const struct in6_addr *addr, return 0; } +static int ping_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr, + int addr_len) +{ + /* This check is 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 (addr_len < SIN6_LEN_RFC2133) + return -EINVAL; + + return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr); +} + static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) { struct inet_sock *inet = inet_sk(sk); @@ -191,6 +206,7 @@ struct proto pingv6_prot = { .init = ping_init_sock, .close = ping_close, .destroy = ping_v6_destroy, + .pre_connect = ping_v6_pre_connect, .connect = ip6_datagram_connect_v6_only, .disconnect = __udp_disconnect, .setsockopt = ipv6_setsockopt, |