From: Eric W. Biederman Date: Sat, 9 May 2015 02:10:31 +0000 (-0500) Subject: net: Modify sk_alloc to not reference count the netns of kernel sockets. X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe;p=openwrt%2Fstaging%2Fblogic.git net: Modify sk_alloc to not reference count the netns of kernel sockets. Now that sk_alloc knows when a kernel socket is being allocated modify it to not reference count the network namespace of kernel sockets. Keep track of if a socket needs reference counting by adding a flag to struct sock called sk_net_refcnt. Update all of the callers of sock_create_kern to stop using sk_change_net and sk_release_kernel as those hacks are no longer needed, to avoid reference counting a kernel socket. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller --- diff --git a/include/net/inet_common.h b/include/net/inet_common.h index 4a92423eefa5..279f83591971 100644 --- a/include/net/inet_common.h +++ b/include/net/inet_common.h @@ -41,7 +41,7 @@ int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, static inline void inet_ctl_sock_destroy(struct sock *sk) { - sk_release_kernel(sk); + sock_release(sk->sk_socket); } #endif diff --git a/include/net/sock.h b/include/net/sock.h index d8dcf91732b0..9e6b2c0b4741 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -184,6 +184,7 @@ struct sock_common { unsigned char skc_reuse:4; unsigned char skc_reuseport:1; unsigned char skc_ipv6only:1; + unsigned char skc_net_refcnt:1; int skc_bound_dev_if; union { struct hlist_node skc_bind_node; @@ -323,6 +324,7 @@ struct sock { #define sk_reuse __sk_common.skc_reuse #define sk_reuseport __sk_common.skc_reuseport #define sk_ipv6only __sk_common.skc_ipv6only +#define sk_net_refcnt __sk_common.skc_net_refcnt #define sk_bound_dev_if __sk_common.skc_bound_dev_if #define sk_bind_node __sk_common.skc_bind_node #define sk_prot __sk_common.skc_prot diff --git a/net/core/sock.c b/net/core/sock.c index cbc3789b830c..9e8968e9ebeb 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1412,7 +1412,10 @@ struct sock *sk_alloc(struct net *net, int family, gfp_t priority, */ sk->sk_prot = sk->sk_prot_creator = prot; sock_lock_init(sk); - sock_net_set(sk, get_net(net)); + sk->sk_net_refcnt = kern ? 0 : 1; + if (likely(sk->sk_net_refcnt)) + get_net(net); + sock_net_set(sk, net); atomic_set(&sk->sk_wmem_alloc, 1); sock_update_classid(sk); @@ -1446,7 +1449,8 @@ static void __sk_free(struct sock *sk) if (sk->sk_peer_cred) put_cred(sk->sk_peer_cred); put_pid(sk->sk_peer_pid); - put_net(sock_net(sk)); + if (likely(sk->sk_net_refcnt)) + put_net(sock_net(sk)); sk_prot_free(sk->sk_prot_creator, sk); } diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index e2dd9cb99d61..235d36afece3 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1430,7 +1430,7 @@ int inet_ctl_sock_create(struct sock **sk, unsigned short family, struct net *net) { struct socket *sock; - int rc = sock_create_kern(&init_net, family, type, protocol, &sock); + int rc = sock_create_kern(net, family, type, protocol, &sock); if (rc == 0) { *sk = sock->sk; @@ -1440,8 +1440,6 @@ int inet_ctl_sock_create(struct sock **sk, unsigned short family, * we do not wish this socket to see incoming packets. */ (*sk)->sk_prot->unhash(*sk); - - sk_change_net(*sk, net); } return rc; } diff --git a/net/ipv4/udp_tunnel.c b/net/ipv4/udp_tunnel.c index 4e2837476967..933ea903f7b8 100644 --- a/net/ipv4/udp_tunnel.c +++ b/net/ipv4/udp_tunnel.c @@ -15,12 +15,10 @@ int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg, struct socket *sock = NULL; struct sockaddr_in udp_addr; - err = sock_create_kern(&init_net, AF_INET, SOCK_DGRAM, 0, &sock); + err = sock_create_kern(net, AF_INET, SOCK_DGRAM, 0, &sock); if (err < 0) goto error; - sk_change_net(sock->sk, net); - udp_addr.sin_family = AF_INET; udp_addr.sin_addr = cfg->local_ip; udp_addr.sin_port = cfg->local_udp_port; @@ -47,7 +45,7 @@ int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg, error: if (sock) { kernel_sock_shutdown(sock, SHUT_RDWR); - sk_release_kernel(sock->sk); + sock_release(sock); } *sockp = NULL; return err; @@ -101,7 +99,7 @@ void udp_tunnel_sock_release(struct socket *sock) { rcu_assign_sk_user_data(sock->sk, NULL); kernel_sock_shutdown(sock, SHUT_RDWR); - sk_release_kernel(sock->sk); + sock_release(sock); } EXPORT_SYMBOL_GPL(udp_tunnel_sock_release); diff --git a/net/ipv6/ip6_udp_tunnel.c b/net/ipv6/ip6_udp_tunnel.c index 478576b61214..e1a1136bda7c 100644 --- a/net/ipv6/ip6_udp_tunnel.c +++ b/net/ipv6/ip6_udp_tunnel.c @@ -19,12 +19,10 @@ int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg, int err; struct socket *sock = NULL; - err = sock_create_kern(&init_net, AF_INET6, SOCK_DGRAM, 0, &sock); + err = sock_create_kern(net, AF_INET6, SOCK_DGRAM, 0, &sock); if (err < 0) goto error; - sk_change_net(sock->sk, net); - udp6_addr.sin6_family = AF_INET6; memcpy(&udp6_addr.sin6_addr, &cfg->local_ip6, sizeof(udp6_addr.sin6_addr)); @@ -55,7 +53,7 @@ int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg, error: if (sock) { kernel_sock_shutdown(sock, SHUT_RDWR); - sk_release_kernel(sock->sk); + sock_release(sock); } *sockp = NULL; return err; diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index ae513a2fe7f3..f6b090df3930 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1334,9 +1334,10 @@ static void l2tp_tunnel_del_work(struct work_struct *work) if (sock) inet_shutdown(sock, 2); } else { - if (sock) + if (sock) { kernel_sock_shutdown(sock, SHUT_RDWR); - sk_release_kernel(sk); + sock_release(sock); + } } l2tp_tunnel_sock_put(sk); @@ -1399,13 +1400,11 @@ static int l2tp_tunnel_sock_create(struct net *net, if (cfg->local_ip6 && cfg->peer_ip6) { struct sockaddr_l2tpip6 ip6_addr = {0}; - err = sock_create_kern(&init_net, AF_INET6, SOCK_DGRAM, + err = sock_create_kern(net, AF_INET6, SOCK_DGRAM, IPPROTO_L2TP, &sock); if (err < 0) goto out; - sk_change_net(sock->sk, net); - ip6_addr.l2tp_family = AF_INET6; memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, sizeof(ip6_addr.l2tp_addr)); @@ -1429,13 +1428,11 @@ static int l2tp_tunnel_sock_create(struct net *net, { struct sockaddr_l2tpip ip_addr = {0}; - err = sock_create_kern(&init_net, AF_INET, SOCK_DGRAM, + err = sock_create_kern(net, AF_INET, SOCK_DGRAM, IPPROTO_L2TP, &sock); if (err < 0) goto out; - sk_change_net(sock->sk, net); - ip_addr.l2tp_family = AF_INET; ip_addr.l2tp_addr = cfg->local_ip; ip_addr.l2tp_conn_id = tunnel_id; @@ -1462,7 +1459,7 @@ out: *sockp = sock; if ((err < 0) && sock) { kernel_sock_shutdown(sock, SHUT_RDWR); - sk_release_kernel(sock->sk); + sock_release(sock); *sockp = NULL; } diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c index 2e9a5b5d1239..b08ba9538d12 100644 --- a/net/netfilter/ipvs/ip_vs_sync.c +++ b/net/netfilter/ipvs/ip_vs_sync.c @@ -1457,18 +1457,12 @@ static struct socket *make_send_sock(struct net *net, int id) struct socket *sock; int result; - /* First create a socket move it to right name space later */ - result = sock_create_kern(&init_net, PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock); + /* First create a socket */ + result = sock_create_kern(net, PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock); if (result < 0) { pr_err("Error during creation of socket; terminating\n"); return ERR_PTR(result); } - /* - * Kernel sockets that are a part of a namespace, should not - * hold a reference to a namespace in order to allow to stop it. - * After sk_change_net should be released using sk_release_kernel. - */ - sk_change_net(sock->sk, net); result = set_mcast_if(sock->sk, ipvs->master_mcast_ifn); if (result < 0) { pr_err("Error setting outbound mcast interface\n"); @@ -1497,7 +1491,7 @@ static struct socket *make_send_sock(struct net *net, int id) return sock; error: - sk_release_kernel(sock->sk); + sock_release(sock); return ERR_PTR(result); } @@ -1518,17 +1512,11 @@ static struct socket *make_receive_sock(struct net *net, int id) int result; /* First create a socket */ - result = sock_create_kern(&init_net, PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock); + result = sock_create_kern(net, PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock); if (result < 0) { pr_err("Error during creation of socket; terminating\n"); return ERR_PTR(result); } - /* - * Kernel sockets that are a part of a namespace, should not - * hold a reference to a namespace in order to allow to stop it. - * After sk_change_net should be released using sk_release_kernel. - */ - sk_change_net(sock->sk, net); /* it is equivalent to the REUSEADDR option in user-space */ sock->sk->sk_reuse = SK_CAN_REUSE; result = sysctl_sync_sock_size(ipvs); @@ -1554,7 +1542,7 @@ static struct socket *make_receive_sock(struct net *net, int id) return sock; error: - sk_release_kernel(sock->sk); + sock_release(sock); return ERR_PTR(result); } @@ -1692,7 +1680,7 @@ done: ip_vs_sync_buff_release(sb); /* release the sending multicast socket */ - sk_release_kernel(tinfo->sock->sk); + sock_release(tinfo->sock); kfree(tinfo); return 0; @@ -1729,7 +1717,7 @@ static int sync_thread_backup(void *data) } /* release the sending multicast socket */ - sk_release_kernel(tinfo->sock->sk); + sock_release(tinfo->sock); kfree(tinfo->buf); kfree(tinfo); @@ -1854,11 +1842,11 @@ int start_sync_thread(struct net *net, int state, char *mcast_ifn, __u8 syncid) return 0; outsocket: - sk_release_kernel(sock->sk); + sock_release(sock); outtinfo: if (tinfo) { - sk_release_kernel(tinfo->sock->sk); + sock_release(tinfo->sock); kfree(tinfo->buf); kfree(tinfo); }