diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index eea5d7844473..d3a9355ac8ac 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -588,41 +588,114 @@ static void pppol2tp_session_init(struct l2tp_session *session) } } +struct l2tp_connect_info { + u8 version; + int fd; + u32 tunnel_id; + u32 peer_tunnel_id; + u32 session_id; + u32 peer_session_id; +}; + +static int pppol2tp_sockaddr_get_info(const void *sa, int sa_len, + struct l2tp_connect_info *info) +{ + switch (sa_len) { + case sizeof(struct sockaddr_pppol2tp): + { + const struct sockaddr_pppol2tp *sa_v2in4 = sa; + + if (sa_v2in4->sa_protocol != PX_PROTO_OL2TP) + return -EINVAL; + + info->version = 2; + info->fd = sa_v2in4->pppol2tp.fd; + info->tunnel_id = sa_v2in4->pppol2tp.s_tunnel; + info->peer_tunnel_id = sa_v2in4->pppol2tp.d_tunnel; + info->session_id = sa_v2in4->pppol2tp.s_session; + info->peer_session_id = sa_v2in4->pppol2tp.d_session; + + break; + } + case sizeof(struct sockaddr_pppol2tpv3): + { + const struct sockaddr_pppol2tpv3 *sa_v3in4 = sa; + + if (sa_v3in4->sa_protocol != PX_PROTO_OL2TP) + return -EINVAL; + + info->version = 3; + info->fd = sa_v3in4->pppol2tp.fd; + info->tunnel_id = sa_v3in4->pppol2tp.s_tunnel; + info->peer_tunnel_id = sa_v3in4->pppol2tp.d_tunnel; + info->session_id = sa_v3in4->pppol2tp.s_session; + info->peer_session_id = sa_v3in4->pppol2tp.d_session; + + break; + } + case sizeof(struct sockaddr_pppol2tpin6): + { + const struct sockaddr_pppol2tpin6 *sa_v2in6 = sa; + + if (sa_v2in6->sa_protocol != PX_PROTO_OL2TP) + return -EINVAL; + + info->version = 2; + info->fd = sa_v2in6->pppol2tp.fd; + info->tunnel_id = sa_v2in6->pppol2tp.s_tunnel; + info->peer_tunnel_id = sa_v2in6->pppol2tp.d_tunnel; + info->session_id = sa_v2in6->pppol2tp.s_session; + info->peer_session_id = sa_v2in6->pppol2tp.d_session; + + break; + } + case sizeof(struct sockaddr_pppol2tpv3in6): + { + const struct sockaddr_pppol2tpv3in6 *sa_v3in6 = sa; + + if (sa_v3in6->sa_protocol != PX_PROTO_OL2TP) + return -EINVAL; + + info->version = 3; + info->fd = sa_v3in6->pppol2tp.fd; + info->tunnel_id = sa_v3in6->pppol2tp.s_tunnel; + info->peer_tunnel_id = sa_v3in6->pppol2tp.d_tunnel; + info->session_id = sa_v3in6->pppol2tp.s_session; + info->peer_session_id = sa_v3in6->pppol2tp.d_session; + + break; + } + default: + return -EINVAL; + } + + return 0; +} + /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket */ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, int sockaddr_len, int flags) { struct sock *sk = sock->sk; - struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr; struct pppox_sock *po = pppox_sk(sk); struct l2tp_session *session = NULL; + struct l2tp_connect_info info; struct l2tp_tunnel *tunnel; struct pppol2tp_session *ps; struct l2tp_session_cfg cfg = { 0, }; - int error = 0; - u32 tunnel_id, peer_tunnel_id; - u32 session_id, peer_session_id; bool drop_refcnt = false; bool drop_tunnel = false; bool new_session = false; bool new_tunnel = false; - int ver = 2; - int fd; + int error; + + error = pppol2tp_sockaddr_get_info(uservaddr, sockaddr_len, &info); + if (error < 0) + return error; lock_sock(sk); - error = -EINVAL; - - if (sockaddr_len != sizeof(struct sockaddr_pppol2tp) && - sockaddr_len != sizeof(struct sockaddr_pppol2tpv3) && - sockaddr_len != sizeof(struct sockaddr_pppol2tpin6) && - sockaddr_len != sizeof(struct sockaddr_pppol2tpv3in6)) - goto end; - - if (sp->sa_protocol != PX_PROTO_OL2TP) - goto end; - /* Check for already bound sockets */ error = -EBUSY; if (sk->sk_state & PPPOX_CONNECTED) @@ -633,56 +706,12 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, if (sk->sk_user_data) goto end; /* socket is already attached */ - /* Get params from socket address. Handle L2TPv2 and L2TPv3. - * This is nasty because there are different sockaddr_pppol2tp - * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use - * the sockaddr size to determine which structure the caller - * is using. - */ - peer_tunnel_id = 0; - if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) { - fd = sp->pppol2tp.fd; - tunnel_id = sp->pppol2tp.s_tunnel; - peer_tunnel_id = sp->pppol2tp.d_tunnel; - session_id = sp->pppol2tp.s_session; - peer_session_id = sp->pppol2tp.d_session; - } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) { - struct sockaddr_pppol2tpv3 *sp3 = - (struct sockaddr_pppol2tpv3 *) sp; - ver = 3; - fd = sp3->pppol2tp.fd; - tunnel_id = sp3->pppol2tp.s_tunnel; - peer_tunnel_id = sp3->pppol2tp.d_tunnel; - session_id = sp3->pppol2tp.s_session; - peer_session_id = sp3->pppol2tp.d_session; - } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) { - struct sockaddr_pppol2tpin6 *sp6 = - (struct sockaddr_pppol2tpin6 *) sp; - fd = sp6->pppol2tp.fd; - tunnel_id = sp6->pppol2tp.s_tunnel; - peer_tunnel_id = sp6->pppol2tp.d_tunnel; - session_id = sp6->pppol2tp.s_session; - peer_session_id = sp6->pppol2tp.d_session; - } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) { - struct sockaddr_pppol2tpv3in6 *sp6 = - (struct sockaddr_pppol2tpv3in6 *) sp; - ver = 3; - fd = sp6->pppol2tp.fd; - tunnel_id = sp6->pppol2tp.s_tunnel; - peer_tunnel_id = sp6->pppol2tp.d_tunnel; - session_id = sp6->pppol2tp.s_session; - peer_session_id = sp6->pppol2tp.d_session; - } else { - error = -EINVAL; - goto end; /* bad socket address */ - } - /* Don't bind if tunnel_id is 0 */ error = -EINVAL; - if (tunnel_id == 0) + if (!info.tunnel_id) goto end; - tunnel = l2tp_tunnel_get(sock_net(sk), tunnel_id); + tunnel = l2tp_tunnel_get(sock_net(sk), info.tunnel_id); if (tunnel) drop_tunnel = true; @@ -690,7 +719,7 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, * peer_session_id is 0. Otherwise look up tunnel using supplied * tunnel id. */ - if ((session_id == 0) && (peer_session_id == 0)) { + if (!info.session_id && !info.peer_session_id) { if (tunnel == NULL) { struct l2tp_tunnel_cfg tcfg = { .encap = L2TP_ENCAPTYPE_UDP, @@ -700,12 +729,16 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, /* Prevent l2tp_tunnel_register() from trying to set up * a kernel socket. */ - if (fd < 0) { + if (info.fd < 0) { error = -EBADF; goto end; } - error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel); + error = l2tp_tunnel_create(sock_net(sk), info.fd, + info.version, + info.tunnel_id, + info.peer_tunnel_id, &tcfg, + &tunnel); if (error < 0) goto end; @@ -734,9 +767,9 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, tunnel->recv_payload_hook = pppol2tp_recv_payload_hook; if (tunnel->peer_tunnel_id == 0) - tunnel->peer_tunnel_id = peer_tunnel_id; + tunnel->peer_tunnel_id = info.peer_tunnel_id; - session = l2tp_session_get(sock_net(sk), tunnel, session_id); + session = l2tp_session_get(sock_net(sk), tunnel, info.session_id); if (session) { drop_refcnt = true; @@ -765,8 +798,8 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, cfg.pw_type = L2TP_PWTYPE_PPP; session = l2tp_session_create(sizeof(struct pppol2tp_session), - tunnel, session_id, - peer_session_id, &cfg); + tunnel, info.session_id, + info.peer_session_id, &cfg); if (IS_ERR(session)) { error = PTR_ERR(session); goto end;