smack: Set the proper NetLabel security attributes for connection requests

[NOTE: based on 07feee8f812f7327a46186f7604df312c8c81962]

This patch ensures the correct labeling of new network connection requests
using Smack and NetLabel.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/security/smack/smack.h b/security/smack/smack.h
index b79582e4fbfd6e82dc2679890731953f5ba1926f..1983196c5bd6996077008a611bf63ce23c1dab92 100644 (file)
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -40,7 +40,6 @@ struct superblock_smack {
 struct socket_smack {
        char            *smk_out;                       /* outbound label */
        char            *smk_in;                        /* inbound label */
-       int             smk_labeled;                    /* label scheme */
        char            smk_packet[SMK_LABELLEN];       /* TCP peer label */
 };
 

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index c1c5f3663b18a58c76f96318dedb25fe5fd059dc..b4e811bb45070d6212843c12cb6c5def12113c2e 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -7,6 +7,8 @@
  *     Casey Schaufler <casey@schaufler-ca.com>
  *
  *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
+ *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
+ *                Paul Moore <paul.moore@hp.com>
  *
  *     This program is free software; you can redistribute it and/or modify
  *     it under the terms of the GNU General Public License version 2,
@@ -20,6 +22,7 @@
 #include <linux/ext2_fs.h>
 #include <linux/kd.h>
 #include <asm/ioctls.h>
+#include <linux/ip.h>
 #include <linux/tcp.h>
 #include <linux/udp.h>
 #include <linux/mutex.h>
@@ -1279,7 +1282,6 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
 
        ssp->smk_in = csp;
        ssp->smk_out = csp;
-       ssp->smk_labeled = SMACK_CIPSO_SOCKET;
        ssp->smk_packet[0] = '\0';
 
        sk->sk_security = ssp;
@@ -1397,16 +1399,6 @@ static int smack_netlabel(struct sock *sk, int labeled)
 
        bh_unlock_sock(sk);
        local_bh_enable();
-       /*
-        * Remember the label scheme used so that it is not
-        * necessary to do the netlabel setting if it has not
-        * changed the next time through.
-        *
-        * The -EDESTADDRREQ case is an indication that there's
-        * a single level host involved.
-        */
-       if (rc == 0)
-               ssp->smk_labeled = labeled;
 
        return rc;
 }
@@ -1551,19 +1543,14 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
                return -EINVAL;
 
        hostsp = smack_host_label((struct sockaddr_in *)sap);
-       if (hostsp == NULL) {
-               if (ssp->smk_labeled != SMACK_CIPSO_SOCKET)
-                       return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
-               return 0;
-       }
+       if (hostsp == NULL)
+               return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
 
        rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE);
        if (rc != 0)
                return rc;
 
-       if (ssp->smk_labeled != SMACK_UNLABELED_SOCKET)
-               return smack_netlabel(sock->sk, SMACK_UNLABELED_SOCKET);
-       return 0;
+       return smack_netlabel(sock->sk, SMACK_UNLABELED_SOCKET);
 }
 
 /**
@@ -2275,21 +2262,14 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
                return 0;
 
        hostsp = smack_host_label(sip);
-       if (hostsp == NULL) {
-               if (ssp->smk_labeled != SMACK_CIPSO_SOCKET)
-                       return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
-               return 0;
-       }
+       if (hostsp == NULL)
+               return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
 
        rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE);
        if (rc != 0)
                return rc;
 
-       if (ssp->smk_labeled != SMACK_UNLABELED_SOCKET)
-               return smack_netlabel(sock->sk, SMACK_UNLABELED_SOCKET);
-
-       return 0;
-
+       return smack_netlabel(sock->sk, SMACK_UNLABELED_SOCKET);
 }
 
 
@@ -2504,22 +2484,14 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
 static void smack_sock_graft(struct sock *sk, struct socket *parent)
 {
        struct socket_smack *ssp;
-       int rc;
 
-       if (sk == NULL)
-               return;
-
-       if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
+       if (sk == NULL ||
+           (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
                return;
 
        ssp = sk->sk_security;
        ssp->smk_in = ssp->smk_out = current_security();
-       ssp->smk_packet[0] = '\0';
-
-       rc = smack_netlabel(sk, SMACK_CIPSO_SOCKET);
-       if (rc != 0)
-               printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
-                      __func__, -rc);
+       /* cssp->smk_packet is already set in smack_inet_csk_clone() */
 }
 
 /**
@@ -2534,35 +2506,82 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent)
 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
                                   struct request_sock *req)
 {
-       struct netlbl_lsm_secattr skb_secattr;
+       u16 family = sk->sk_family;
        struct socket_smack *ssp = sk->sk_security;
+       struct netlbl_lsm_secattr secattr;
+       struct sockaddr_in addr;
+       struct iphdr *hdr;
        char smack[SMK_LABELLEN];
        int rc;
 
-       if (skb == NULL)
-               return -EACCES;
+       /* handle mapped IPv4 packets arriving via IPv6 sockets */
+       if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
+               family = PF_INET;
 
-       netlbl_secattr_init(&skb_secattr);
-       rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr);
+       netlbl_secattr_init(&secattr);
+       rc = netlbl_skbuff_getattr(skb, family, &secattr);
        if (rc == 0)
-               smack_from_secattr(&skb_secattr, smack);
+               smack_from_secattr(&secattr, smack);
        else
                strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
-       netlbl_secattr_destroy(&skb_secattr);
+       netlbl_secattr_destroy(&secattr);
+
        /*
-        * Receiving a packet requires that the other end
-        * be able to write here. Read access is not required.
-        *
-        * If the request is successful save the peer's label
-        * so that SO_PEERCRED can report it.
-        */
+       * Receiving a packet requires that the other end be able to write
+       * here. Read access is not required.
+       */
        rc = smk_access(smack, ssp->smk_in, MAY_WRITE);
-       if (rc == 0)
-               strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
+       if (rc != 0)
+               return rc;
+
+       /*
+       * Save the peer's label in the request_sock so we can later setup
+       * smk_packet in the child socket so that SO_PEERCRED can report it.
+       */
+       req->peer_secid = smack_to_secid(smack);
+
+       /*
+       * We need to decide if we want to label the incoming connection here
+       * if we do we only need to label the request_sock and the stack will
+       * propogate the wire-label to the sock when it is created.
+       */
+       hdr = ip_hdr(skb);
+       addr.sin_addr.s_addr = hdr->saddr;
+       rcu_read_lock();
+       if (smack_host_label(&addr) == NULL) {
+               rcu_read_unlock();
+               netlbl_secattr_init(&secattr);
+               smack_to_secattr(smack, &secattr);
+               rc = netlbl_req_setattr(req, &secattr);
+               netlbl_secattr_destroy(&secattr);
+       } else {
+               rcu_read_unlock();
+               netlbl_req_delattr(req);
+       }
 
        return rc;
 }
 
+/**
+* smack_inet_csk_clone - Copy the connection information to the new socket
+* @sk: the new socket
+* @req: the connection's request_sock
+*
+* Transfer the connection's peer label to the newly created socket.
+*/
+static void smack_inet_csk_clone(struct sock *sk,
+                                const struct request_sock *req)
+{
+       struct socket_smack *ssp = sk->sk_security;
+       char *smack;
+
+       if (req->peer_secid != 0) {
+               smack = smack_from_secid(req->peer_secid);
+               strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
+       } else
+               ssp->smk_packet[0] = '\0';
+}
+
 /*
  * Key management security hooks
  *
@@ -2915,6 +2934,7 @@ struct security_operations smack_ops = {
        .sk_free_security =             smack_sk_free_security,
        .sock_graft =                   smack_sock_graft,
        .inet_conn_request =            smack_inet_conn_request,
+       .inet_csk_clone =               smack_inet_csk_clone,
 
  /* key management security hooks */
 #ifdef CONFIG_KEYS