[LSM]: Networking top-level socket operation hooks.

diff --git a/include/linux/security.h b/include/linux/security.h
index 5e2d1da2e7f75a73080adc0146b5f26b885771e5..2597ce9145962b865f27666ddaaa3ebca9deba44 100644 (file)
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -64,6 +64,10 @@ extern void cap_task_reparent_to_init (struct task_struct *p);
 #define LSM_SETID_FS   8
 
 /* forward declares to avoid warnings */
+struct sock;
+struct socket;
+struct sockaddr;
+struct msghdr;
 struct sk_buff;
 struct nfsctl_arg;
 struct sched_param;
@@ -584,6 +588,103 @@ struct swap_info_struct;
  *     is being reparented to the init task.
  *     @p contains the task_struct for the kernel thread.
  *
+ * Security hooks for socket operations.
+ *
+ * @socket_create:
+ *     Check permissions prior to creating a new socket.
+ *     @family contains the requested protocol family.
+ *     @type contains the requested communications type.
+ *     @protocol contains the requested protocol.
+ *     Return 0 if permission is granted.
+ * @socket_post_create:
+ *     This hook allows a module to update or allocate a per-socket security
+ *     structure. Note that the security field was not added directly to the
+ *     socket structure, but rather, the socket security information is stored
+ *     in the associated inode.  Typically, the inode alloc_security hook will
+ *     allocate and and attach security information to
+ *     sock->inode->i_security.  This hook may be used to update the
+ *     sock->inode->i_security field with additional information that wasn't
+ *     available when the inode was allocated.
+ *     @sock contains the newly created socket structure.
+ *     @family contains the requested protocol family.
+ *     @type contains the requested communications type.
+ *     @protocol contains the requested protocol.
+ * @socket_bind:
+ *     Check permission before socket protocol layer bind operation is
+ *     performed and the socket @sock is bound to the address specified in the
+ *     @address parameter.
+ *     @sock contains the socket structure.
+ *     @address contains the address to bind to.
+ *     @addrlen contains the length of address.
+ *     Return 0 if permission is granted.  
+ * @socket_connect:
+ *     Check permission before socket protocol layer connect operation
+ *     attempts to connect socket @sock to a remote address, @address.
+ *     @sock contains the socket structure.
+ *     @address contains the address of remote endpoint.
+ *     @addrlen contains the length of address.
+ *     Return 0 if permission is granted.  
+ * @socket_listen:
+ *     Check permission before socket protocol layer listen operation.
+ *     @sock contains the socket structure.
+ *     @backlog contains the maximum length for the pending connection queue.
+ *     Return 0 if permission is granted.
+ * @socket_accept:
+ *     Check permission before accepting a new connection.  Note that the new
+ *     socket, @newsock, has been created and some information copied to it,
+ *     but the accept operation has not actually been performed.
+ *     @sock contains the listening socket structure.
+ *     @newsock contains the newly created server socket for connection.
+ *     Return 0 if permission is granted.
+ * @socket_post_accept:
+ *     This hook allows a security module to copy security
+ *     information into the newly created socket's inode.
+ *     @sock contains the listening socket structure.
+ *     @newsock contains the newly created server socket for connection.
+ * @socket_sendmsg:
+ *     Check permission before transmitting a message to another socket.
+ *     @sock contains the socket structure.
+ *     @msg contains the message to be transmitted.
+ *     @size contains the size of message.
+ *     Return 0 if permission is granted.
+ * @socket_recvmsg:
+ *     Check permission before receiving a message from a socket.
+ *     @sock contains the socket structure.
+ *     @msg contains the message structure.
+ *     @size contains the size of message structure.
+ *     @flags contains the operational flags.
+ *     Return 0 if permission is granted.  
+ * @socket_getsockname:
+ *     Check permission before the local address (name) of the socket object
+ *     @sock is retrieved.
+ *     @sock contains the socket structure.
+ *     Return 0 if permission is granted.
+ * @socket_getpeername:
+ *     Check permission before the remote address (name) of a socket object
+ *     @sock is retrieved.
+ *     @sock contains the socket structure.
+ *     Return 0 if permission is granted.
+ * @socket_getsockopt:
+ *     Check permissions before retrieving the options associated with socket
+ *     @sock.
+ *     @sock contains the socket structure.
+ *     @level contains the protocol level to retrieve option from.
+ *     @optname contains the name of option to retrieve.
+ *     Return 0 if permission is granted.
+ * @socket_setsockopt:
+ *     Check permissions before setting the options associated with socket
+ *     @sock.
+ *     @sock contains the socket structure.
+ *     @level contains the protocol level to set options for.
+ *     @optname contains the name of the option to set.
+ *     Return 0 if permission is granted.  
+ * @socket_shutdown:
+ *     Checks permission before all or part of a connection on the socket
+ *     @sock is shut down.
+ *     @sock contains the socket structure.
+ *     @how contains the flag indicating how future sends and receives are handled.
+ *     Return 0 if permission is granted.
+ *
  * Security hooks affecting all System V IPC operations.
  *
  * @ipc_permission:
@@ -952,6 +1053,26 @@ struct security_operations {
                                    struct security_operations *ops);
 
 #ifdef CONFIG_SECURITY_NETWORK
+       int (*socket_create) (int family, int type, int protocol);
+       void (*socket_post_create) (struct socket * sock, int family,
+                                   int type, int protocol);
+       int (*socket_bind) (struct socket * sock,
+                           struct sockaddr * address, int addrlen);
+       int (*socket_connect) (struct socket * sock,
+                              struct sockaddr * address, int addrlen);
+       int (*socket_listen) (struct socket * sock, int backlog);
+       int (*socket_accept) (struct socket * sock, struct socket * newsock);
+       void (*socket_post_accept) (struct socket * sock,
+                                   struct socket * newsock);
+       int (*socket_sendmsg) (struct socket * sock,
+                              struct msghdr * msg, int size);
+       int (*socket_recvmsg) (struct socket * sock,
+                              struct msghdr * msg, int size, int flags);
+       int (*socket_getsockname) (struct socket * sock);
+       int (*socket_getpeername) (struct socket * sock);
+       int (*socket_getsockopt) (struct socket * sock, int level, int optname);
+       int (*socket_setsockopt) (struct socket * sock, int level, int optname);
+       int (*socket_shutdown) (struct socket * sock, int how);
 #endif /* CONFIG_SECURITY_NETWORK */
 };
 
@@ -2108,7 +2229,171 @@ static inline int security_sem_semop (struct sem_array * sma,
 #endif /* CONFIG_SECURITY */
 
 #ifdef CONFIG_SECURITY_NETWORK
+static inline int security_socket_create (int family, int type, int protocol)
+{
+       return security_ops->socket_create(family, type, protocol);
+}
+
+static inline void security_socket_post_create(struct socket * sock, 
+                                              int family,
+                                              int type, 
+                                              int protocol)
+{
+       security_ops->socket_post_create(sock, family, type, protocol);
+}
+
+static inline int security_socket_bind(struct socket * sock, 
+                                      struct sockaddr * address, 
+                                      int addrlen)
+{
+       return security_ops->socket_bind(sock, address, addrlen);
+}
+
+static inline int security_socket_connect(struct socket * sock, 
+                                         struct sockaddr * address, 
+                                         int addrlen)
+{
+       return security_ops->socket_connect(sock, address, addrlen);
+}
+
+static inline int security_socket_listen(struct socket * sock, int backlog)
+{
+       return security_ops->socket_listen(sock, backlog);
+}
+
+static inline int security_socket_accept(struct socket * sock, 
+                                        struct socket * newsock)
+{
+       return security_ops->socket_accept(sock, newsock);
+}
+
+static inline void security_socket_post_accept(struct socket * sock, 
+                                              struct socket * newsock)
+{
+       security_ops->socket_post_accept(sock, newsock);
+}
+
+static inline int security_socket_sendmsg(struct socket * sock, 
+                                         struct msghdr * msg, int size)
+{
+       return security_ops->socket_sendmsg(sock, msg, size);
+}
+
+static inline int security_socket_recvmsg(struct socket * sock, 
+                                         struct msghdr * msg, int size, 
+                                         int flags)
+{
+       return security_ops->socket_recvmsg(sock, msg, size, flags);
+}
+
+static inline int security_socket_getsockname(struct socket * sock)
+{
+       return security_ops->socket_getsockname(sock);
+}
+
+static inline int security_socket_getpeername(struct socket * sock)
+{
+       return security_ops->socket_getpeername(sock);
+}
+
+static inline int security_socket_getsockopt(struct socket * sock, 
+                                            int level, int optname)
+{
+       return security_ops->socket_getsockopt(sock, level, optname);
+}
+
+static inline int security_socket_setsockopt(struct socket * sock, 
+                                            int level, int optname)
+{
+       return security_ops->socket_setsockopt(sock, level, optname);
+}
+
+static inline int security_socket_shutdown(struct socket * sock, int how)
+{
+       return security_ops->socket_shutdown(sock, how);
+}
 #else  /* CONFIG_SECURITY_NETWORK */
+static inline int security_socket_create (int family, int type, int protocol)
+{
+       return 0;
+}
+
+static inline void security_socket_post_create(struct socket * sock, 
+                                              int family,
+                                              int type, 
+                                              int protocol)
+{
+}
+
+static inline int security_socket_bind(struct socket * sock, 
+                                      struct sockaddr * address, 
+                                      int addrlen)
+{
+       return 0;
+}
+
+static inline int security_socket_connect(struct socket * sock, 
+                                         struct sockaddr * address, 
+                                         int addrlen)
+{
+       return 0;
+}
+
+static inline int security_socket_listen(struct socket * sock, int backlog)
+{
+       return 0;
+}
+
+static inline int security_socket_accept(struct socket * sock, 
+                                        struct socket * newsock)
+{
+       return 0;
+}
+
+static inline void security_socket_post_accept(struct socket * sock, 
+                                              struct socket * newsock)
+{
+}
+
+static inline int security_socket_sendmsg(struct socket * sock, 
+                                         struct msghdr * msg, int size)
+{
+       return 0;
+}
+
+static inline int security_socket_recvmsg(struct socket * sock, 
+                                         struct msghdr * msg, int size, 
+                                         int flags)
+{
+       return 0;
+}
+
+static inline int security_socket_getsockname(struct socket * sock)
+{
+       return 0;
+}
+
+static inline int security_socket_getpeername(struct socket * sock)
+{
+       return 0;
+}
+
+static inline int security_socket_getsockopt(struct socket * sock, 
+                                            int level, int optname)
+{
+       return 0;
+}
+
+static inline int security_socket_setsockopt(struct socket * sock, 
+                                            int level, int optname)
+{
+       return 0;
+}
+
+static inline int security_socket_shutdown(struct socket * sock, int how)
+{
+       return 0;
+}
 #endif /* CONFIG_SECURITY_NETWORK */
 
 #endif /* ! __LINUX_SECURITY_H */

diff --git a/net/socket.c b/net/socket.c
index b17a1944444a8645b8f7be882af14e7d58b20ae0..5e7636d1408a20eac07f5a41c3e9c555e99f26b7 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -77,6 +77,7 @@
 #include <linux/highmem.h>
 #include <linux/divert.h>
 #include <linux/mount.h>
+#include <linux/security.h>
 
 #if defined(CONFIG_KMOD) && defined(CONFIG_NET)
 #include <linux/kmod.h>
@@ -527,6 +528,10 @@ static int __sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
        si->msg = msg;
        si->size = size;
 
+       err = security_socket_sendmsg(sock, msg, size);
+       if (err)
+               return err;
+
        err = scm_send(sock, msg, si->scm);
        if (err >= 0) {
                err = sock->ops->sendmsg(iocb, sock, msg, size, si->scm);
@@ -551,6 +556,7 @@ int sock_sendmsg(struct socket *sock, struct msghdr *msg, int size)
 
 int __sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, int size, int flags)
 {
+       int err;
        struct sock_iocb *si = kiocb_to_siocb(iocb);
 
        si->sock = sock;
@@ -560,6 +566,10 @@ int __sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
        si->size = size;
        si->flags = flags;
 
+       err = security_socket_recvmsg(sock, msg, size, flags);
+       if (err)
+               return err;
+
        memset(si->scm, 0, sizeof(*si->scm));
 
        size = sock->ops->recvmsg(iocb, sock, msg, size, flags, si->scm);
@@ -963,6 +973,7 @@ int sock_wake_async(struct socket *sock, int how, int band)
 int sock_create(int family, int type, int protocol, struct socket **res)
 {
        int i;
+       int err;
        struct socket *sock;
 
        /*
@@ -986,6 +997,10 @@ int sock_create(int family, int type, int protocol, struct socket **res)
                }
                family = PF_PACKET;
        }
+
+       err = security_socket_create(family, type, protocol);
+       if (err)
+               return err;
                
 #if defined(CONFIG_KMOD) && defined(CONFIG_NET)
        /* Attempt to load a protocol module if the find failed. 
@@ -1031,6 +1046,7 @@ int sock_create(int family, int type, int protocol, struct socket **res)
        }
 
        *res = sock;
+       security_socket_post_create(sock, family, type, protocol);
 
 out:
        net_family_read_unlock();
@@ -1141,8 +1157,14 @@ asmlinkage long sys_bind(int fd, struct sockaddr *umyaddr, int addrlen)
 
        if((sock = sockfd_lookup(fd,&err))!=NULL)
        {
-               if((err=move_addr_to_kernel(umyaddr,addrlen,address))>=0)
+               if((err=move_addr_to_kernel(umyaddr,addrlen,address))>=0) {
+                       err = security_socket_bind(sock, (struct sockaddr *)address, addrlen);
+                       if (err) {
+                               sockfd_put(sock);
+                               return err;
+                       }
                        err = sock->ops->bind(sock, (struct sockaddr *)address, addrlen);
+               }
                sockfd_put(sock);
        }                       
        return err;
@@ -1163,6 +1185,13 @@ asmlinkage long sys_listen(int fd, int backlog)
        if ((sock = sockfd_lookup(fd, &err)) != NULL) {
                if ((unsigned) backlog > SOMAXCONN)
                        backlog = SOMAXCONN;
+
+               err = security_socket_listen(sock, backlog);
+               if (err) {
+                       sockfd_put(sock);
+                       return err;
+               }
+
                err=sock->ops->listen(sock, backlog);
                sockfd_put(sock);
        }
@@ -1199,6 +1228,10 @@ asmlinkage long sys_accept(int fd, struct sockaddr *upeer_sockaddr, int *upeer_a
        newsock->type = sock->type;
        newsock->ops = sock->ops;
 
+       err = security_socket_accept(sock, newsock);
+       if (err)
+               goto out_release;
+
        err = sock->ops->accept(sock, newsock, sock->file->f_flags);
        if (err < 0)
                goto out_release;
@@ -1218,6 +1251,8 @@ asmlinkage long sys_accept(int fd, struct sockaddr *upeer_sockaddr, int *upeer_a
        if ((err = sock_map_fd(newsock)) < 0)
                goto out_release;
 
+       security_socket_post_accept(sock, newsock);
+
 out_put:
        sockfd_put(sock);
 out:
@@ -1253,6 +1288,11 @@ asmlinkage long sys_connect(int fd, struct sockaddr *uservaddr, int addrlen)
        err = move_addr_to_kernel(uservaddr, addrlen, address);
        if (err < 0)
                goto out_put;
+
+       err = security_socket_connect(sock, (struct sockaddr *)address, addrlen);
+       if (err)
+               goto out_put;
+
        err = sock->ops->connect(sock, (struct sockaddr *) address, addrlen,
                                 sock->file->f_flags);
 out_put:
@@ -1275,6 +1315,11 @@ asmlinkage long sys_getsockname(int fd, struct sockaddr *usockaddr, int *usockad
        sock = sockfd_lookup(fd, &err);
        if (!sock)
                goto out;
+
+       err = security_socket_getsockname(sock);
+       if (err)
+               goto out_put;
+
        err = sock->ops->getname(sock, (struct sockaddr *)address, &len, 0);
        if (err)
                goto out_put;
@@ -1299,6 +1344,12 @@ asmlinkage long sys_getpeername(int fd, struct sockaddr *usockaddr, int *usockad
 
        if ((sock = sockfd_lookup(fd, &err))!=NULL)
        {
+               err = security_socket_getpeername(sock);
+               if (err) {
+                       sockfd_put(sock);
+                       return err;
+               }
+
                err = sock->ops->getname(sock, (struct sockaddr *)address, &len, 1);
                if (!err)
                        err=move_addr_to_user(address,len, usockaddr, usockaddr_len);
@@ -1427,6 +1478,12 @@ asmlinkage long sys_setsockopt(int fd, int level, int optname, char *optval, int
                        
        if ((sock = sockfd_lookup(fd, &err))!=NULL)
        {
+               err = security_socket_setsockopt(sock,level,optname);
+               if (err) {
+                       sockfd_put(sock);
+                       return err;
+               }
+
                if (level == SOL_SOCKET)
                        err=sock_setsockopt(sock,level,optname,optval,optlen);
                else
@@ -1448,6 +1505,13 @@ asmlinkage long sys_getsockopt(int fd, int level, int optname, char *optval, int
 
        if ((sock = sockfd_lookup(fd, &err))!=NULL)
        {
+               err = security_socket_getsockopt(sock, level, 
+                                                          optname);
+               if (err) {
+                       sockfd_put(sock);
+                       return err;
+               }
+
                if (level == SOL_SOCKET)
                        err=sock_getsockopt(sock,level,optname,optval,optlen);
                else
@@ -1469,6 +1533,12 @@ asmlinkage long sys_shutdown(int fd, int how)
 
        if ((sock = sockfd_lookup(fd, &err))!=NULL)
        {
+               err = security_socket_shutdown(sock, how);
+               if (err) {
+                       sockfd_put(sock);
+                       return err;
+               }
+                               
                err=sock->ops->shutdown(sock, how);
                sockfd_put(sock);
        }

diff --git a/security/dummy.c b/security/dummy.c
index 7403b45a869f9a3d93c931304cf4cc74b1789332..1472bb6da0c9195d5a21cdbaf2388ec41a5c070b 100644 (file)
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -20,7 +20,7 @@
 #include <linux/security.h>
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
-
+#include <net/sock.h>
 
 static int dummy_ptrace (struct task_struct *parent, struct task_struct *child)
 {
@@ -598,6 +598,82 @@ static int dummy_sem_semop (struct sem_array *sma,
 }
 
 #ifdef CONFIG_SECURITY_NETWORK
+static int dummy_socket_create (int family, int type, int protocol)
+{
+       return 0;
+}
+
+static void dummy_socket_post_create (struct socket *sock, int family, int type,
+                                     int protocol)
+{
+       return;
+}
+
+static int dummy_socket_bind (struct socket *sock, struct sockaddr *address,
+                             int addrlen)
+{
+       return 0;
+}
+
+static int dummy_socket_connect (struct socket *sock, struct sockaddr *address,
+                                int addrlen)
+{
+       return 0;
+}
+
+static int dummy_socket_listen (struct socket *sock, int backlog)
+{
+       return 0;
+}
+
+static int dummy_socket_accept (struct socket *sock, struct socket *newsock)
+{
+       return 0;
+}
+
+static void dummy_socket_post_accept (struct socket *sock, 
+                                     struct socket *newsock)
+{
+       return;
+}
+
+static int dummy_socket_sendmsg (struct socket *sock, struct msghdr *msg,
+                                int size)
+{
+       return 0;
+}
+
+static int dummy_socket_recvmsg (struct socket *sock, struct msghdr *msg,
+                                int size, int flags)
+{
+       return 0;
+}
+
+static int dummy_socket_getsockname (struct socket *sock)
+{
+       return 0;
+}
+
+static int dummy_socket_getpeername (struct socket *sock)
+{
+       return 0;
+}
+
+static int dummy_socket_setsockopt (struct socket *sock, int level, int optname)
+{
+       return 0;
+}
+
+static int dummy_socket_getsockopt (struct socket *sock, int level, int optname)
+{
+       return 0;
+}
+
+static int dummy_socket_shutdown (struct socket *sock, int how)
+{
+       return 0;
+}
+
 #endif /* CONFIG_SECURITY_NETWORK */
 
 static int dummy_register_security (const char *name, struct security_operations *ops)
@@ -729,6 +805,20 @@ void security_fixup_ops (struct security_operations *ops)
        set_to_dummy_if_null(ops, register_security);
        set_to_dummy_if_null(ops, unregister_security);
 #ifdef CONFIG_SECURITY_NETWORK
+       set_to_dummy_if_null(ops, socket_create);
+       set_to_dummy_if_null(ops, socket_post_create);
+       set_to_dummy_if_null(ops, socket_bind);
+       set_to_dummy_if_null(ops, socket_connect);
+       set_to_dummy_if_null(ops, socket_listen);
+       set_to_dummy_if_null(ops, socket_accept);
+       set_to_dummy_if_null(ops, socket_post_accept);
+       set_to_dummy_if_null(ops, socket_sendmsg);
+       set_to_dummy_if_null(ops, socket_recvmsg);
+       set_to_dummy_if_null(ops, socket_getsockname);
+       set_to_dummy_if_null(ops, socket_getpeername);
+       set_to_dummy_if_null(ops, socket_setsockopt);
+       set_to_dummy_if_null(ops, socket_getsockopt);
+       set_to_dummy_if_null(ops, socket_shutdown);
 #endif /* CONFIG_SECURITY_NETWORK */
 }