diff options
author | Andrey Ignatov <rdna@fb.com> | 2018-03-30 15:08:04 -0700 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-03-31 02:15:43 +0200 |
commit | 3679d585bbc07a1ac4448d5b478b492cad3587ce (patch) | |
tree | 15cfea104f4ee4dcb55005a2ca101631eefa3f2f /net/ipv4/af_inet.c | |
parent | e50b0a6f089308bec6b2d0198abed231dee4d277 (diff) |
net: Introduce __inet_bind() and __inet6_bind
Refactor `bind()` code to make it ready to be called from BPF helper
function `bpf_bind()` (will be added soon). Implementation of
`inet_bind()` and `inet6_bind()` is separated into `__inet_bind()` and
`__inet6_bind()` correspondingly. These function can be used from both
`sk_prot->bind` and `bpf_bind()` contexts.
New functions have two additional arguments.
`force_bind_address_no_port` forces binding to IP only w/o checking
`inet_sock.bind_address_no_port` field. It'll allow to bind local end of
a connection to desired IP in `bpf_bind()` w/o changing
`bind_address_no_port` field of a socket. It's useful since `bpf_bind()`
can return an error and we'd need to restore original value of
`bind_address_no_port` in that case if we changed this before calling to
the helper.
`with_lock` specifies whether to lock socket when working with `struct
sk` or not. The argument is set to `true` for `sk_prot->bind`, i.e. old
behavior is preserved. But it will be set to `false` for `bpf_bind()`
use-case. The reason is all call-sites, where `bpf_bind()` will be
called, already hold that socket lock.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'net/ipv4/af_inet.c')
-rw-r--r-- | net/ipv4/af_inet.c | 39 |
1 files changed, 24 insertions, 15 deletions
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 2dec266507dc..e203a39d6988 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -432,30 +432,37 @@ EXPORT_SYMBOL(inet_release); int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) { - struct sockaddr_in *addr = (struct sockaddr_in *)uaddr; struct sock *sk = sock->sk; - struct inet_sock *inet = inet_sk(sk); - struct net *net = sock_net(sk); - unsigned short snum; - int chk_addr_ret; - u32 tb_id = RT_TABLE_LOCAL; int err; /* If the socket has its own bind function then use it. (RAW) */ if (sk->sk_prot->bind) { - err = sk->sk_prot->bind(sk, uaddr, addr_len); - goto out; + return sk->sk_prot->bind(sk, uaddr, addr_len); } - err = -EINVAL; if (addr_len < sizeof(struct sockaddr_in)) - goto out; + return -EINVAL; /* BPF prog is run before any checks are done so that if the prog * changes context in a wrong way it will be caught. */ err = BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr); if (err) - goto out; + return err; + + return __inet_bind(sk, uaddr, addr_len, false, true); +} +EXPORT_SYMBOL(inet_bind); + +int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, + bool force_bind_address_no_port, bool with_lock) +{ + struct sockaddr_in *addr = (struct sockaddr_in *)uaddr; + struct inet_sock *inet = inet_sk(sk); + struct net *net = sock_net(sk); + unsigned short snum; + int chk_addr_ret; + u32 tb_id = RT_TABLE_LOCAL; + int err; if (addr->sin_family != AF_INET) { /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET) @@ -499,7 +506,8 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) * would be illegal to use them (multicast/broadcast) in * which case the sending device address is used. */ - lock_sock(sk); + if (with_lock) + lock_sock(sk); /* Check these errors (active socket, double bind). */ err = -EINVAL; @@ -511,7 +519,8 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) inet->inet_saddr = 0; /* Use device */ /* Make sure we are allowed to bind here. */ - if ((snum || !inet->bind_address_no_port) && + if ((snum || !(inet->bind_address_no_port || + force_bind_address_no_port)) && sk->sk_prot->get_port(sk, snum)) { inet->inet_saddr = inet->inet_rcv_saddr = 0; err = -EADDRINUSE; @@ -528,11 +537,11 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) sk_dst_reset(sk); err = 0; out_release_sock: - release_sock(sk); + if (with_lock) + release_sock(sk); out: return err; } -EXPORT_SYMBOL(inet_bind); int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags) |