From accc609322ef5ed44cba6d2d70c741afc76385fb Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:29 -0400 Subject: selinux: Cleanup the NetLabel glue code We were doing a lot of extra work in selinux_netlbl_sock_graft() what wasn't necessary so this patch removes that code. It also removes the redundant second argument to selinux_netlbl_sock_setsid() which allows us to simplify a few other functions. Signed-off-by: Paul Moore Acked-by: James Morris --- security/selinux/netlabel.c | 38 ++++++++++---------------------------- 1 file changed, 10 insertions(+), 28 deletions(-) (limited to 'security/selinux/netlabel.c') diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index 89b418392f1..b9ce5fcf343 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -66,22 +66,24 @@ static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb, /** * selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism * @sk: the socket to label - * @sid: the SID to use * * Description: - * Attempt to label a socket using the NetLabel mechanism using the given - * SID. Returns zero values on success, negative values on failure. + * Attempt to label a socket using the NetLabel mechanism. Returns zero values + * on success, negative values on failure. * */ -static int selinux_netlbl_sock_setsid(struct sock *sk, u32 sid) +static int selinux_netlbl_sock_setsid(struct sock *sk) { int rc; struct sk_security_struct *sksec = sk->sk_security; struct netlbl_lsm_secattr secattr; + if (sksec->nlbl_state != NLBL_REQUIRE) + return 0; + netlbl_secattr_init(&secattr); - rc = security_netlbl_sid_to_secattr(sid, &secattr); + rc = security_netlbl_sid_to_secattr(sksec->sid, &secattr); if (rc != 0) goto sock_setsid_return; rc = netlbl_sock_setattr(sk, &secattr); @@ -174,24 +176,10 @@ int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, */ void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock) { - struct sk_security_struct *sksec = sk->sk_security; - struct netlbl_lsm_secattr secattr; - u32 nlbl_peer_sid; - - if (sksec->nlbl_state != NLBL_REQUIRE) - return; - - netlbl_secattr_init(&secattr); - if (netlbl_sock_getattr(sk, &secattr) == 0 && - secattr.flags != NETLBL_SECATTR_NONE && - security_netlbl_secattr_to_sid(&secattr, &nlbl_peer_sid) == 0) - sksec->peer_sid = nlbl_peer_sid; - netlbl_secattr_destroy(&secattr); - /* Try to set the NetLabel on the socket to save time later, if we fail * here we will pick up the pieces in later calls to * selinux_netlbl_inode_permission(). */ - selinux_netlbl_sock_setsid(sk, sksec->sid); + selinux_netlbl_sock_setsid(sk); } /** @@ -205,13 +193,7 @@ void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock) */ int selinux_netlbl_socket_post_create(struct socket *sock) { - struct sock *sk = sock->sk; - struct sk_security_struct *sksec = sk->sk_security; - - if (sksec->nlbl_state != NLBL_REQUIRE) - return 0; - - return selinux_netlbl_sock_setsid(sk, sksec->sid); + return selinux_netlbl_sock_setsid(sock->sk); } /** @@ -246,7 +228,7 @@ int selinux_netlbl_inode_permission(struct inode *inode, int mask) local_bh_disable(); bh_lock_sock_nested(sk); if (likely(sksec->nlbl_state == NLBL_REQUIRE)) - rc = selinux_netlbl_sock_setsid(sk, sksec->sid); + rc = selinux_netlbl_sock_setsid(sk); else rc = 0; bh_unlock_sock(sk); -- cgit v1.2.3-70-g09d2 From dfaebe9825ff34983778f287101bc5f3bce00640 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:31 -0400 Subject: selinux: Fix missing calls to netlbl_skbuff_err() At some point I think I messed up and dropped the calls to netlbl_skbuff_err() which are necessary for CIPSO to send error notifications to remote systems. This patch re-introduces the error handling calls into the SELinux code. Signed-off-by: Paul Moore Acked-by: James Morris --- include/net/netlabel.h | 6 ++++-- net/netlabel/netlabel_kapi.c | 5 +++-- security/selinux/hooks.c | 19 +++++++++++++++---- security/selinux/include/netlabel.h | 9 +++++++++ security/selinux/netlabel.c | 20 +++++++++++++++++++- 5 files changed, 50 insertions(+), 9 deletions(-) (limited to 'security/selinux/netlabel.c') diff --git a/include/net/netlabel.h b/include/net/netlabel.h index 5303749b709..e16db096126 100644 --- a/include/net/netlabel.h +++ b/include/net/netlabel.h @@ -382,7 +382,7 @@ int netlbl_sock_getattr(struct sock *sk, int netlbl_skbuff_getattr(const struct sk_buff *skb, u16 family, struct netlbl_lsm_secattr *secattr); -void netlbl_skbuff_err(struct sk_buff *skb, int error); +void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway); /* * LSM label mapping cache operations @@ -454,7 +454,9 @@ static inline int netlbl_skbuff_getattr(const struct sk_buff *skb, { return -ENOSYS; } -static inline void netlbl_skbuff_err(struct sk_buff *skb, int error) +static inline void netlbl_skbuff_err(struct sk_buff *skb, + int error, + int gateway) { return; } diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c index 6c211fe9778..22faba620e4 100644 --- a/net/netlabel/netlabel_kapi.c +++ b/net/netlabel/netlabel_kapi.c @@ -490,6 +490,7 @@ int netlbl_skbuff_getattr(const struct sk_buff *skb, * netlbl_skbuff_err - Handle a LSM error on a sk_buff * @skb: the packet * @error: the error code + * @gateway: true if host is acting as a gateway, false otherwise * * Description: * Deal with a LSM problem when handling the packet in @skb, typically this is @@ -497,10 +498,10 @@ int netlbl_skbuff_getattr(const struct sk_buff *skb, * according to the packet's labeling protocol. * */ -void netlbl_skbuff_err(struct sk_buff *skb, int error) +void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway) { if (CIPSO_V4_OPTEXIST(skb)) - cipso_v4_error(skb, error, 0); + cipso_v4_error(skb, error, gateway); } /** diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b520667a24b..a91146a6b37 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4101,6 +4101,8 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, return err; err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, PEER__RECV, &ad); + if (err) + selinux_netlbl_err(skb, err, 0); } else { err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad); if (err) @@ -4156,10 +4158,14 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) return err; err = selinux_inet_sys_rcv_skb(skb->iif, addrp, family, peer_sid, &ad); - if (err) + if (err) { + selinux_netlbl_err(skb, err, 0); return err; + } err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, PEER__RECV, &ad); + if (err) + selinux_netlbl_err(skb, err, 0); } if (secmark_active) { @@ -4396,6 +4402,7 @@ out: static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, u16 family) { + int err; char *addrp; u32 peer_sid; struct avc_audit_data ad; @@ -4419,10 +4426,14 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0) return NF_DROP; - if (peerlbl_active) - if (selinux_inet_sys_rcv_skb(ifindex, addrp, family, - peer_sid, &ad) != 0) + if (peerlbl_active) { + err = selinux_inet_sys_rcv_skb(ifindex, addrp, family, + peer_sid, &ad); + if (err) { + selinux_netlbl_err(skb, err, 1); return NF_DROP; + } + } if (secmark_active) if (avc_has_perm(peer_sid, skb->secmark, diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h index 487a7d81fe2..d4e3ac8a7fb 100644 --- a/security/selinux/include/netlabel.h +++ b/security/selinux/include/netlabel.h @@ -39,6 +39,8 @@ #ifdef CONFIG_NETLABEL void selinux_netlbl_cache_invalidate(void); +void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway); + void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec, int family); @@ -63,6 +65,13 @@ static inline void selinux_netlbl_cache_invalidate(void) return; } +static inline void selinux_netlbl_err(struct sk_buff *skb, + int error, + int gateway) +{ + return; +} + static inline void selinux_netlbl_sk_security_reset( struct sk_security_struct *ssec, int family) diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index b9ce5fcf343..4053f7fc95f 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -107,6 +107,24 @@ void selinux_netlbl_cache_invalidate(void) netlbl_cache_invalidate(); } +/** + * selinux_netlbl_err - Handle a NetLabel packet error + * @skb: the packet + * @error: the error code + * @gateway: true if host is acting as a gateway, false otherwise + * + * Description: + * When a packet is dropped due to a call to avc_has_perm() pass the error + * code to the NetLabel subsystem so any protocol specific processing can be + * done. This is safe to call even if you are unsure if NetLabel labeling is + * present on the packet, NetLabel is smart enough to only act when it should. + * + */ +void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway) +{ + netlbl_skbuff_err(skb, error, gateway); +} + /** * selinux_netlbl_sk_security_reset - Reset the NetLabel fields * @ssec: the sk_security_struct @@ -289,7 +307,7 @@ int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, return 0; if (nlbl_sid != SECINITSID_UNLABELED) - netlbl_skbuff_err(skb, rc); + netlbl_skbuff_err(skb, rc, 0); return rc; } -- cgit v1.2.3-70-g09d2 From 948bf85c1bc9a84754786a9d5dd99b7ecc46451e Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:32 -0400 Subject: netlabel: Add functionality to set the security attributes of a packet This patch builds upon the new NetLabel address selector functionality by providing the NetLabel KAPI and CIPSO engine support needed to enable the new packet-based labeling. The only new addition to the NetLabel KAPI at this point is shown below: * int netlbl_skbuff_setattr(skb, family, secattr) ... and is designed to be called from a Netfilter hook after the packet's IP header has been populated such as in the FORWARD or LOCAL_OUT hooks. This patch also provides the necessary SELinux hooks to support this new functionality. Smack support is not currently included due to uncertainty regarding the permissions needed to expand the Smack network access controls. Signed-off-by: Paul Moore Reviewed-by: James Morris --- include/net/cipso_ipv4.h | 16 +++ include/net/netlabel.h | 9 ++ net/ipv4/cipso_ipv4.c | 222 +++++++++++++++++++++++++++++------- net/netlabel/netlabel_kapi.c | 60 ++++++++++ security/selinux/hooks.c | 50 +++++++- security/selinux/include/netlabel.h | 9 ++ security/selinux/include/objsec.h | 1 + security/selinux/netlabel.c | 68 ++++++++++- 8 files changed, 393 insertions(+), 42 deletions(-) (limited to 'security/selinux/netlabel.c') diff --git a/include/net/cipso_ipv4.h b/include/net/cipso_ipv4.h index 5fe6556fb3c..2ce093ba553 100644 --- a/include/net/cipso_ipv4.h +++ b/include/net/cipso_ipv4.h @@ -208,6 +208,10 @@ int cipso_v4_sock_setattr(struct sock *sk, const struct cipso_v4_doi *doi_def, const struct netlbl_lsm_secattr *secattr); int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr); +int cipso_v4_skbuff_setattr(struct sk_buff *skb, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr); +int cipso_v4_skbuff_delattr(struct sk_buff *skb); int cipso_v4_skbuff_getattr(const struct sk_buff *skb, struct netlbl_lsm_secattr *secattr); int cipso_v4_validate(unsigned char **option); @@ -232,6 +236,18 @@ static inline int cipso_v4_sock_getattr(struct sock *sk, return -ENOSYS; } +static inline int cipso_v4_skbuff_setattr(struct sk_buff *skb, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + return -ENOSYS; +} + +static inline int cipso_v4_skbuff_delattr(struct sk_buff *skb) +{ + return -ENOSYS; +} + static inline int cipso_v4_skbuff_getattr(const struct sk_buff *skb, struct netlbl_lsm_secattr *secattr) { diff --git a/include/net/netlabel.h b/include/net/netlabel.h index 0729f8ce504..3f67e6d49e4 100644 --- a/include/net/netlabel.h +++ b/include/net/netlabel.h @@ -382,6 +382,9 @@ int netlbl_sock_setattr(struct sock *sk, const struct netlbl_lsm_secattr *secattr); int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr); +int netlbl_skbuff_setattr(struct sk_buff *skb, + u16 family, + const struct netlbl_lsm_secattr *secattr); int netlbl_skbuff_getattr(const struct sk_buff *skb, u16 family, struct netlbl_lsm_secattr *secattr); @@ -451,6 +454,12 @@ static inline int netlbl_sock_getattr(struct sock *sk, { return -ENOSYS; } +static inline int netlbl_skbuff_setattr(struct sk_buff *skb, + u16 family, + const struct netlbl_lsm_secattr *secattr) +{ + return -ENOSYS; +} static inline int netlbl_skbuff_getattr(const struct sk_buff *skb, u16 family, struct netlbl_lsm_secattr *secattr) diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index bf87eddfec3..e13d6dbb66a 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -13,7 +13,7 @@ */ /* - * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -1665,48 +1665,27 @@ void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway) } /** - * cipso_v4_sock_setattr - Add a CIPSO option to a socket - * @sk: the socket + * cipso_v4_genopt - Generate a CIPSO option + * @buf: the option buffer + * @buf_len: the size of opt_buf * @doi_def: the CIPSO DOI to use - * @secattr: the specific security attributes of the socket + * @secattr: the security attributes * * Description: - * Set the CIPSO option on the given socket using the DOI definition and - * security attributes passed to the function. This function requires - * exclusive access to @sk, which means it either needs to be in the - * process of being created or locked. Returns zero on success and negative - * values on failure. + * Generate a CIPSO option using the DOI definition and security attributes + * passed to the function. Returns the length of the option on success and + * negative values on failure. * */ -int cipso_v4_sock_setattr(struct sock *sk, - const struct cipso_v4_doi *doi_def, - const struct netlbl_lsm_secattr *secattr) +static int cipso_v4_genopt(unsigned char *buf, u32 buf_len, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) { - int ret_val = -EPERM; + int ret_val; u32 iter; - unsigned char *buf; - u32 buf_len = 0; - u32 opt_len; - struct ip_options *opt = NULL; - struct inet_sock *sk_inet; - struct inet_connection_sock *sk_conn; - - /* In the case of sock_create_lite(), the sock->sk field is not - * defined yet but it is not a problem as the only users of these - * "lite" PF_INET sockets are functions which do an accept() call - * afterwards so we will label the socket as part of the accept(). */ - if (sk == NULL) - return 0; - /* We allocate the maximum CIPSO option size here so we are probably - * being a little wasteful, but it makes our life _much_ easier later - * on and after all we are only talking about 40 bytes. */ - buf_len = CIPSO_V4_OPT_LEN_MAX; - buf = kmalloc(buf_len, GFP_ATOMIC); - if (buf == NULL) { - ret_val = -ENOMEM; - goto socket_setattr_failure; - } + if (buf_len <= CIPSO_V4_HDR_LEN) + return -ENOSPC; /* XXX - This code assumes only one tag per CIPSO option which isn't * really a good assumption to make but since we only support the MAC @@ -1734,8 +1713,7 @@ int cipso_v4_sock_setattr(struct sock *sk, buf_len - CIPSO_V4_HDR_LEN); break; default: - ret_val = -EPERM; - goto socket_setattr_failure; + return -EPERM; } iter++; @@ -1743,9 +1721,58 @@ int cipso_v4_sock_setattr(struct sock *sk, iter < CIPSO_V4_TAG_MAXCNT && doi_def->tags[iter] != CIPSO_V4_TAG_INVALID); if (ret_val < 0) - goto socket_setattr_failure; + return ret_val; cipso_v4_gentag_hdr(doi_def, buf, ret_val); - buf_len = CIPSO_V4_HDR_LEN + ret_val; + return CIPSO_V4_HDR_LEN + ret_val; +} + +/** + * cipso_v4_sock_setattr - Add a CIPSO option to a socket + * @sk: the socket + * @doi_def: the CIPSO DOI to use + * @secattr: the specific security attributes of the socket + * + * Description: + * Set the CIPSO option on the given socket using the DOI definition and + * security attributes passed to the function. This function requires + * exclusive access to @sk, which means it either needs to be in the + * process of being created or locked. Returns zero on success and negative + * values on failure. + * + */ +int cipso_v4_sock_setattr(struct sock *sk, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val = -EPERM; + unsigned char *buf = NULL; + u32 buf_len; + u32 opt_len; + struct ip_options *opt = NULL; + struct inet_sock *sk_inet; + struct inet_connection_sock *sk_conn; + + /* In the case of sock_create_lite(), the sock->sk field is not + * defined yet but it is not a problem as the only users of these + * "lite" PF_INET sockets are functions which do an accept() call + * afterwards so we will label the socket as part of the accept(). */ + if (sk == NULL) + return 0; + + /* We allocate the maximum CIPSO option size here so we are probably + * being a little wasteful, but it makes our life _much_ easier later + * on and after all we are only talking about 40 bytes. */ + buf_len = CIPSO_V4_OPT_LEN_MAX; + buf = kmalloc(buf_len, GFP_ATOMIC); + if (buf == NULL) { + ret_val = -ENOMEM; + goto socket_setattr_failure; + } + + ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); + if (ret_val < 0) + goto socket_setattr_failure; + buf_len = ret_val; /* We can't use ip_options_get() directly because it makes a call to * ip_options_get_alloc() which allocates memory with GFP_KERNEL and @@ -1853,6 +1880,123 @@ int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) secattr); } +/** + * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet + * @skb: the packet + * @secattr: the security attributes + * + * Description: + * Set the CIPSO option on the given packet based on the security attributes. + * Returns a pointer to the IP header on success and NULL on failure. + * + */ +int cipso_v4_skbuff_setattr(struct sk_buff *skb, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + struct iphdr *iph; + struct ip_options *opt = &IPCB(skb)->opt; + unsigned char buf[CIPSO_V4_OPT_LEN_MAX]; + u32 buf_len = CIPSO_V4_OPT_LEN_MAX; + u32 opt_len; + int len_delta; + + buf_len = cipso_v4_genopt(buf, buf_len, doi_def, secattr); + if (buf_len < 0) + return buf_len; + opt_len = (buf_len + 3) & ~3; + + /* we overwrite any existing options to ensure that we have enough + * room for the CIPSO option, the reason is that we _need_ to guarantee + * that the security label is applied to the packet - we do the same + * thing when using the socket options and it hasn't caused a problem, + * if we need to we can always revisit this choice later */ + + len_delta = opt_len - opt->optlen; + /* if we don't ensure enough headroom we could panic on the skb_push() + * call below so make sure we have enough, we are also "mangling" the + * packet so we should probably do a copy-on-write call anyway */ + ret_val = skb_cow(skb, skb_headroom(skb) + len_delta); + if (ret_val < 0) + return ret_val; + + if (len_delta > 0) { + /* we assume that the header + opt->optlen have already been + * "pushed" in ip_options_build() or similar */ + iph = ip_hdr(skb); + skb_push(skb, len_delta); + memmove((char *)iph - len_delta, iph, iph->ihl << 2); + skb_reset_network_header(skb); + iph = ip_hdr(skb); + } else if (len_delta < 0) { + iph = ip_hdr(skb); + memset(iph + 1, IPOPT_NOP, opt->optlen); + } else + iph = ip_hdr(skb); + + if (opt->optlen > 0) + memset(opt, 0, sizeof(*opt)); + opt->optlen = opt_len; + opt->cipso = sizeof(struct iphdr); + opt->is_changed = 1; + + /* we have to do the following because we are being called from a + * netfilter hook which means the packet already has had the header + * fields populated and the checksum calculated - yes this means we + * are doing more work than needed but we do it to keep the core + * stack clean and tidy */ + memcpy(iph + 1, buf, buf_len); + if (opt_len > buf_len) + memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len); + if (len_delta != 0) { + iph->ihl = 5 + (opt_len >> 2); + iph->tot_len = htons(skb->len); + } + ip_send_check(iph); + + return 0; +} + +/** + * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet + * @skb: the packet + * + * Description: + * Removes any and all CIPSO options from the given packet. Returns zero on + * success, negative values on failure. + * + */ +int cipso_v4_skbuff_delattr(struct sk_buff *skb) +{ + int ret_val; + struct iphdr *iph; + struct ip_options *opt = &IPCB(skb)->opt; + unsigned char *cipso_ptr; + + if (opt->cipso == 0) + return 0; + + /* since we are changing the packet we should make a copy */ + ret_val = skb_cow(skb, skb_headroom(skb)); + if (ret_val < 0) + return ret_val; + + /* the easiest thing to do is just replace the cipso option with noop + * options since we don't change the size of the packet, although we + * still need to recalculate the checksum */ + + iph = ip_hdr(skb); + cipso_ptr = (unsigned char *)iph + opt->cipso; + memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]); + opt->cipso = 0; + opt->is_changed = 1; + + ip_send_check(iph); + + return 0; +} + /** * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option * @skb: the packet diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c index 8b820dc9806..cc8047d1f50 100644 --- a/net/netlabel/netlabel_kapi.c +++ b/net/netlabel/netlabel_kapi.c @@ -472,6 +472,66 @@ int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) return cipso_v4_sock_getattr(sk, secattr); } +/** + * netlbl_skbuff_setattr - Label a packet using the correct protocol + * @skb: the packet + * @family: protocol family + * @secattr: the security attributes + * + * Description: + * Attach the correct label to the given packet using the security attributes + * specified in @secattr. Returns zero on success, negative values on failure. + * + */ +int netlbl_skbuff_setattr(struct sk_buff *skb, + u16 family, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + struct iphdr *hdr4; + struct netlbl_domaddr4_map *af4_entry; + + rcu_read_lock(); + switch (family) { + case AF_INET: + hdr4 = ip_hdr(skb); + af4_entry = netlbl_domhsh_getentry_af4(secattr->domain, + hdr4->daddr); + if (af4_entry == NULL) { + ret_val = -ENOENT; + goto skbuff_setattr_return; + } + switch (af4_entry->type) { + case NETLBL_NLTYPE_CIPSOV4: + ret_val = cipso_v4_skbuff_setattr(skb, + af4_entry->type_def.cipsov4, + secattr); + break; + case NETLBL_NLTYPE_UNLABELED: + /* just delete the protocols we support for right now + * but we could remove other protocols if needed */ + ret_val = cipso_v4_skbuff_delattr(skb); + break; + default: + ret_val = -ENOENT; + } + break; +#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) + case AF_INET6: + /* since we don't support any IPv6 labeling protocols right + * now we can optimize everything away until we do */ + ret_val = 0; + break; +#endif /* IPv6 */ + default: + ret_val = 0; + } + +skbuff_setattr_return: + rcu_read_unlock(); + return ret_val; +} + /** * netlbl_skbuff_getattr - Determine the security attributes of a packet * @skb: the packet diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index a91146a6b37..7432bdd5d36 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4407,13 +4407,15 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, u32 peer_sid; struct avc_audit_data ad; u8 secmark_active; + u8 netlbl_active; u8 peerlbl_active; if (!selinux_policycap_netpeer) return NF_ACCEPT; secmark_active = selinux_secmark_enabled(); - peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); + netlbl_active = netlbl_enabled(); + peerlbl_active = netlbl_active || selinux_xfrm_enabled(); if (!secmark_active && !peerlbl_active) return NF_ACCEPT; @@ -4440,6 +4442,14 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, SECCLASS_PACKET, PACKET__FORWARD_IN, &ad)) return NF_DROP; + if (netlbl_active) + /* we do this in the FORWARD path and not the POST_ROUTING + * path because we want to make sure we apply the necessary + * labeling before IPsec is applied so we can leverage AH + * protection */ + if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0) + return NF_DROP; + return NF_ACCEPT; } @@ -4463,6 +4473,37 @@ static unsigned int selinux_ipv6_forward(unsigned int hooknum, } #endif /* IPV6 */ +static unsigned int selinux_ip_output(struct sk_buff *skb, + u16 family) +{ + u32 sid; + + if (!netlbl_enabled()) + return NF_ACCEPT; + + /* we do this in the LOCAL_OUT path and not the POST_ROUTING path + * because we want to make sure we apply the necessary labeling + * before IPsec is applied so we can leverage AH protection */ + if (skb->sk) { + struct sk_security_struct *sksec = skb->sk->sk_security; + sid = sksec->sid; + } else + sid = SECINITSID_KERNEL; + if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0) + return NF_DROP; + + return NF_ACCEPT; +} + +static unsigned int selinux_ipv4_output(unsigned int hooknum, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + return selinux_ip_output(skb, PF_INET); +} + static int selinux_ip_postroute_iptables_compat(struct sock *sk, int ifindex, struct avc_audit_data *ad, @@ -5700,6 +5741,13 @@ static struct nf_hook_ops selinux_ipv4_ops[] = { .pf = PF_INET, .hooknum = NF_INET_FORWARD, .priority = NF_IP_PRI_SELINUX_FIRST, + }, + { + .hook = selinux_ipv4_output, + .owner = THIS_MODULE, + .pf = PF_INET, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_SELINUX_FIRST, } }; diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h index d4e3ac8a7fb..b3e6ae071fc 100644 --- a/security/selinux/include/netlabel.h +++ b/security/selinux/include/netlabel.h @@ -48,6 +48,9 @@ int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u16 family, u32 *type, u32 *sid); +int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, + u16 family, + u32 sid); void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock); int selinux_netlbl_socket_post_create(struct socket *sock); @@ -88,6 +91,12 @@ static inline int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, *sid = SECSID_NULL; return 0; } +static inline int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, + u16 family, + u32 sid) +{ + return 0; +} static inline void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock) diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 91070ab874c..f46dd1c3d01 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -117,6 +117,7 @@ struct sk_security_struct { NLBL_UNSET = 0, NLBL_REQUIRE, NLBL_LABELED, + NLBL_REQSKB, } nlbl_state; #endif }; diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index 4053f7fc95f..090404d6e51 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -9,7 +9,7 @@ */ /* - * (c) Copyright Hewlett-Packard Development Company, L.P., 2007 + * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -31,6 +31,8 @@ #include #include #include +#include +#include #include "objsec.h" #include "security.h" @@ -77,6 +79,8 @@ static int selinux_netlbl_sock_setsid(struct sock *sk) int rc; struct sk_security_struct *sksec = sk->sk_security; struct netlbl_lsm_secattr secattr; + struct inet_sock *sk_inet; + struct inet_connection_sock *sk_conn; if (sksec->nlbl_state != NLBL_REQUIRE) return 0; @@ -87,8 +91,29 @@ static int selinux_netlbl_sock_setsid(struct sock *sk) if (rc != 0) goto sock_setsid_return; rc = netlbl_sock_setattr(sk, &secattr); - if (rc == 0) + switch (rc) { + case 0: sksec->nlbl_state = NLBL_LABELED; + break; + case -EDESTADDRREQ: + /* we are going to possibly end up labeling the individual + * packets later which is problematic for stream sockets + * because of the additional IP header size, our solution is to + * allow for the maximum IP header length (40 bytes for IPv4, + * we don't have to worry about IPv6 yet) just in case */ + sk_inet = inet_sk(sk); + if (sk_inet->is_icsk) { + sk_conn = inet_csk(sk); + if (sk_inet->opt) + sk_conn->icsk_ext_hdr_len -= + sk_inet->opt->optlen; + sk_conn->icsk_ext_hdr_len += 40; + sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); + } + sksec->nlbl_state = NLBL_REQSKB; + rc = 0; + break; + } sock_setsid_return: netlbl_secattr_destroy(&secattr); @@ -182,6 +207,45 @@ int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, return rc; } +/** + * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid + * @skb: the packet + * @family: protocol family + * @sid: the SID + * + * Description + * Call the NetLabel mechanism to set the label of a packet using @sid. + * Returns zero on auccess, negative values on failure. + * + */ +int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, + u16 family, + u32 sid) +{ + int rc; + struct netlbl_lsm_secattr secattr; + struct sock *sk; + + /* if this is a locally generated packet check to see if it is already + * being labeled by it's parent socket, if it is just exit */ + sk = skb->sk; + if (sk != NULL) { + struct sk_security_struct *sksec = sk->sk_security; + if (sksec->nlbl_state != NLBL_REQSKB) + return 0; + } + + netlbl_secattr_init(&secattr); + rc = security_netlbl_sid_to_secattr(sid, &secattr); + if (rc != 0) + goto skbuff_setsid_return; + rc = netlbl_skbuff_setattr(skb, family, &secattr); + +skbuff_setsid_return: + netlbl_secattr_destroy(&secattr); + return rc; +} + /** * selinux_netlbl_sock_graft - Netlabel the new socket * @sk: the new connection -- cgit v1.2.3-70-g09d2 From 014ab19a69c325f52d7bae54ceeda73d6307ae0c Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:33 -0400 Subject: selinux: Set socket NetLabel based on connection endpoint Previous work enabled the use of address based NetLabel selectors, which while highly useful, brought the potential for additional per-packet overhead when used. This patch attempts to solve that by applying NetLabel socket labels when sockets are connect()'d. This should alleviate the per-packet NetLabel labeling for all connected sockets (yes, it even works for connected DGRAM sockets). Signed-off-by: Paul Moore Reviewed-by: James Morris --- include/net/cipso_ipv4.h | 5 ++ include/net/netlabel.h | 13 ++++ net/ipv4/cipso_ipv4.c | 74 ++++++++++++++++++ net/netlabel/netlabel_kapi.c | 78 ++++++++++++++++++- security/selinux/hooks.c | 11 +-- security/selinux/include/netlabel.h | 19 ++++- security/selinux/include/objsec.h | 1 + security/selinux/netlabel.c | 147 +++++++++++++++++++++++++++++------- 8 files changed, 311 insertions(+), 37 deletions(-) (limited to 'security/selinux/netlabel.c') diff --git a/include/net/cipso_ipv4.h b/include/net/cipso_ipv4.h index 2ce093ba553..811febf97ca 100644 --- a/include/net/cipso_ipv4.h +++ b/include/net/cipso_ipv4.h @@ -207,6 +207,7 @@ void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway); int cipso_v4_sock_setattr(struct sock *sk, const struct cipso_v4_doi *doi_def, const struct netlbl_lsm_secattr *secattr); +void cipso_v4_sock_delattr(struct sock *sk); int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr); int cipso_v4_skbuff_setattr(struct sk_buff *skb, const struct cipso_v4_doi *doi_def, @@ -230,6 +231,10 @@ static inline int cipso_v4_sock_setattr(struct sock *sk, return -ENOSYS; } +static inline void cipso_v4_sock_delattr(struct sock *sk) +{ +} + static inline int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) { diff --git a/include/net/netlabel.h b/include/net/netlabel.h index 3f67e6d49e4..074cad40ac6 100644 --- a/include/net/netlabel.h +++ b/include/net/netlabel.h @@ -380,8 +380,12 @@ int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap, int netlbl_enabled(void); int netlbl_sock_setattr(struct sock *sk, const struct netlbl_lsm_secattr *secattr); +void netlbl_sock_delattr(struct sock *sk); int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr); +int netlbl_conn_setattr(struct sock *sk, + struct sockaddr *addr, + const struct netlbl_lsm_secattr *secattr); int netlbl_skbuff_setattr(struct sk_buff *skb, u16 family, const struct netlbl_lsm_secattr *secattr); @@ -449,11 +453,20 @@ static inline int netlbl_sock_setattr(struct sock *sk, { return -ENOSYS; } +static inline void netlbl_sock_delattr(struct sock *sk) +{ +} static inline int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) { return -ENOSYS; } +static inline int netlbl_conn_setattr(struct sock *sk, + struct sockaddr *addr, + const struct netlbl_lsm_secattr *secattr) +{ + return -ENOSYS; +} static inline int netlbl_skbuff_setattr(struct sk_buff *skb, u16 family, const struct netlbl_lsm_secattr *secattr) diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index e13d6dbb66a..23768b9d6b6 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -1809,6 +1809,80 @@ socket_setattr_failure: return ret_val; } +/** + * cipso_v4_sock_delattr - Delete the CIPSO option from a socket + * @sk: the socket + * + * Description: + * Removes the CIPSO option from a socket, if present. + * + */ +void cipso_v4_sock_delattr(struct sock *sk) +{ + u8 hdr_delta; + struct ip_options *opt; + struct inet_sock *sk_inet; + + sk_inet = inet_sk(sk); + opt = sk_inet->opt; + if (opt == NULL || opt->cipso == 0) + return; + + if (opt->srr || opt->rr || opt->ts || opt->router_alert) { + u8 cipso_len; + u8 cipso_off; + unsigned char *cipso_ptr; + int iter; + int optlen_new; + + cipso_off = opt->cipso - sizeof(struct iphdr); + cipso_ptr = &opt->__data[cipso_off]; + cipso_len = cipso_ptr[1]; + + if (opt->srr > opt->cipso) + opt->srr -= cipso_len; + if (opt->rr > opt->cipso) + opt->rr -= cipso_len; + if (opt->ts > opt->cipso) + opt->ts -= cipso_len; + if (opt->router_alert > opt->cipso) + opt->router_alert -= cipso_len; + opt->cipso = 0; + + memmove(cipso_ptr, cipso_ptr + cipso_len, + opt->optlen - cipso_off - cipso_len); + + /* determining the new total option length is tricky because of + * the padding necessary, the only thing i can think to do at + * this point is walk the options one-by-one, skipping the + * padding at the end to determine the actual option size and + * from there we can determine the new total option length */ + iter = 0; + optlen_new = 0; + while (iter < opt->optlen) + if (opt->__data[iter] != IPOPT_NOP) { + iter += opt->__data[iter + 1]; + optlen_new = iter; + } else + iter++; + hdr_delta = opt->optlen; + opt->optlen = (optlen_new + 3) & ~3; + hdr_delta -= opt->optlen; + } else { + /* only the cipso option was present on the socket so we can + * remove the entire option struct */ + sk_inet->opt = NULL; + hdr_delta = opt->optlen; + kfree(opt); + } + + if (sk_inet->is_icsk && hdr_delta > 0) { + struct inet_connection_sock *sk_conn = inet_csk(sk); + sk_conn->icsk_ext_hdr_len -= hdr_delta; + sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); + } +} + /** * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions * @cipso: the CIPSO v4 option diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c index cc8047d1f50..78fc557689b 100644 --- a/net/netlabel/netlabel_kapi.c +++ b/net/netlabel/netlabel_kapi.c @@ -10,7 +10,7 @@ */ /* - * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -455,6 +455,20 @@ socket_setattr_return: return ret_val; } +/** + * netlbl_sock_delattr - Delete all the NetLabel labels on a socket + * @sk: the socket + * + * Description: + * Remove all the NetLabel labeling from @sk. The caller is responsible for + * ensuring that @sk is locked. + * + */ +void netlbl_sock_delattr(struct sock *sk) +{ + cipso_v4_sock_delattr(sk); +} + /** * netlbl_sock_getattr - Determine the security attributes of a sock * @sk: the sock @@ -472,6 +486,68 @@ int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) return cipso_v4_sock_getattr(sk, secattr); } +/** + * netlbl_conn_setattr - Label a connected socket using the correct protocol + * @sk: the socket to label + * @addr: the destination address + * @secattr: the security attributes + * + * Description: + * Attach the correct label to the given connected socket using the security + * attributes specified in @secattr. The caller is responsible for ensuring + * that @sk is locked. Returns zero on success, negative values on failure. + * + */ +int netlbl_conn_setattr(struct sock *sk, + struct sockaddr *addr, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + struct sockaddr_in *addr4; + struct netlbl_domaddr4_map *af4_entry; + + rcu_read_lock(); + switch (addr->sa_family) { + case AF_INET: + addr4 = (struct sockaddr_in *)addr; + af4_entry = netlbl_domhsh_getentry_af4(secattr->domain, + addr4->sin_addr.s_addr); + if (af4_entry == NULL) { + ret_val = -ENOENT; + goto conn_setattr_return; + } + switch (af4_entry->type) { + case NETLBL_NLTYPE_CIPSOV4: + ret_val = cipso_v4_sock_setattr(sk, + af4_entry->type_def.cipsov4, + secattr); + break; + case NETLBL_NLTYPE_UNLABELED: + /* just delete the protocols we support for right now + * but we could remove other protocols if needed */ + cipso_v4_sock_delattr(sk); + ret_val = 0; + break; + default: + ret_val = -ENOENT; + } + break; +#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) + case AF_INET6: + /* since we don't support any IPv6 labeling protocols right + * now we can optimize everything away until we do */ + ret_val = 0; + break; +#endif /* IPv6 */ + default: + ret_val = 0; + } + +conn_setattr_return: + rcu_read_unlock(); + return ret_val; +} + /** * netlbl_skbuff_setattr - Label a packet using the correct protocol * @skb: the packet diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 7432bdd5d36..632ac3e80a6 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3794,6 +3794,7 @@ out: static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) { + struct sock *sk = sock->sk; struct inode_security_struct *isec; int err; @@ -3807,7 +3808,6 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, isec = SOCK_INODE(sock)->i_security; if (isec->sclass == SECCLASS_TCP_SOCKET || isec->sclass == SECCLASS_DCCP_SOCKET) { - struct sock *sk = sock->sk; struct avc_audit_data ad; struct sockaddr_in *addr4 = NULL; struct sockaddr_in6 *addr6 = NULL; @@ -3841,6 +3841,8 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, goto out; } + err = selinux_netlbl_socket_connect(sk, address); + out: return err; } @@ -4290,8 +4292,6 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent) sk->sk_family == PF_UNIX) isec->sid = sksec->sid; sksec->sclass = isec->sclass; - - selinux_netlbl_sock_graft(sk, parent); } static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, @@ -4342,8 +4342,7 @@ static void selinux_inet_csk_clone(struct sock *newsk, selinux_netlbl_sk_security_reset(newsksec, req->rsk_ops->family); } -static void selinux_inet_conn_established(struct sock *sk, - struct sk_buff *skb) +static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) { u16 family = sk->sk_family; struct sk_security_struct *sksec = sk->sk_security; @@ -4353,6 +4352,8 @@ static void selinux_inet_conn_established(struct sock *sk, family = PF_INET; selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); + + selinux_netlbl_inet_conn_established(sk, family); } static void selinux_req_classify_flow(const struct request_sock *req, diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h index b3e6ae071fc..982bac0ac32 100644 --- a/security/selinux/include/netlabel.h +++ b/security/selinux/include/netlabel.h @@ -52,7 +52,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, u16 family, u32 sid); -void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock); +void selinux_netlbl_inet_conn_established(struct sock *sk, u16 family); int selinux_netlbl_socket_post_create(struct socket *sock); int selinux_netlbl_inode_permission(struct inode *inode, int mask); int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, @@ -62,6 +62,8 @@ int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, int selinux_netlbl_socket_setsockopt(struct socket *sock, int level, int optname); +int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr); + #else static inline void selinux_netlbl_cache_invalidate(void) { @@ -98,8 +100,14 @@ static inline int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, return 0; } -static inline void selinux_netlbl_sock_graft(struct sock *sk, - struct socket *sock) +static inline int selinux_netlbl_conn_setsid(struct sock *sk, + struct sockaddr *addr) +{ + return 0; +} + +static inline void selinux_netlbl_inet_conn_established(struct sock *sk, + u16 family) { return; } @@ -125,6 +133,11 @@ static inline int selinux_netlbl_socket_setsockopt(struct socket *sock, { return 0; } +static inline int selinux_netlbl_socket_connect(struct sock *sk, + struct sockaddr *addr) +{ + return 0; +} #endif /* CONFIG_NETLABEL */ #endif diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index f46dd1c3d01..ad34787c6c0 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -118,6 +118,7 @@ struct sk_security_struct { NLBL_REQUIRE, NLBL_LABELED, NLBL_REQSKB, + NLBL_CONNLABELED, } nlbl_state; #endif }; diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index 090404d6e51..b22b7dafa0e 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -29,10 +29,12 @@ #include #include +#include +#include #include #include -#include -#include +#include +#include #include "objsec.h" #include "security.h" @@ -79,8 +81,6 @@ static int selinux_netlbl_sock_setsid(struct sock *sk) int rc; struct sk_security_struct *sksec = sk->sk_security; struct netlbl_lsm_secattr secattr; - struct inet_sock *sk_inet; - struct inet_connection_sock *sk_conn; if (sksec->nlbl_state != NLBL_REQUIRE) return 0; @@ -96,20 +96,6 @@ static int selinux_netlbl_sock_setsid(struct sock *sk) sksec->nlbl_state = NLBL_LABELED; break; case -EDESTADDRREQ: - /* we are going to possibly end up labeling the individual - * packets later which is problematic for stream sockets - * because of the additional IP header size, our solution is to - * allow for the maximum IP header length (40 bytes for IPv4, - * we don't have to worry about IPv6 yet) just in case */ - sk_inet = inet_sk(sk); - if (sk_inet->is_icsk) { - sk_conn = inet_csk(sk); - if (sk_inet->opt) - sk_conn->icsk_ext_hdr_len -= - sk_inet->opt->optlen; - sk_conn->icsk_ext_hdr_len += 40; - sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); - } sksec->nlbl_state = NLBL_REQSKB; rc = 0; break; @@ -247,21 +233,77 @@ skbuff_setsid_return: } /** - * selinux_netlbl_sock_graft - Netlabel the new socket + * selinux_netlbl_inet_conn_established - Netlabel the newly accepted connection * @sk: the new connection - * @sock: the new socket * * Description: - * The connection represented by @sk is being grafted onto @sock so set the - * socket's NetLabel to match the SID of @sk. + * A new connection has been established on @sk so make sure it is labeled + * correctly with the NetLabel susbsystem. * */ -void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock) +void selinux_netlbl_inet_conn_established(struct sock *sk, u16 family) { - /* Try to set the NetLabel on the socket to save time later, if we fail - * here we will pick up the pieces in later calls to - * selinux_netlbl_inode_permission(). */ - selinux_netlbl_sock_setsid(sk); + int rc; + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr secattr; + struct inet_sock *sk_inet = inet_sk(sk); + struct sockaddr_in addr; + + if (sksec->nlbl_state != NLBL_REQUIRE) + return; + + netlbl_secattr_init(&secattr); + if (security_netlbl_sid_to_secattr(sksec->sid, &secattr) != 0) + goto inet_conn_established_return; + + rc = netlbl_sock_setattr(sk, &secattr); + switch (rc) { + case 0: + sksec->nlbl_state = NLBL_LABELED; + break; + case -EDESTADDRREQ: + /* no PF_INET6 support yet because we don't support any IPv6 + * labeling protocols */ + if (family != PF_INET) { + sksec->nlbl_state = NLBL_UNSET; + goto inet_conn_established_return; + } + + addr.sin_family = family; + addr.sin_addr.s_addr = sk_inet->daddr; + if (netlbl_conn_setattr(sk, (struct sockaddr *)&addr, + &secattr) != 0) { + /* we failed to label the connected socket (could be + * for a variety of reasons, the actual "why" isn't + * important here) so we have to go to our backup plan, + * labeling the packets individually in the netfilter + * local output hook. this is okay but we need to + * adjust the MSS of the connection to take into + * account any labeling overhead, since we don't know + * the exact overhead at this point we'll use the worst + * case value which is 40 bytes for IPv4 */ + struct inet_connection_sock *sk_conn = inet_csk(sk); + sk_conn->icsk_ext_hdr_len += 40 - + (sk_inet->opt ? sk_inet->opt->optlen : 0); + sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); + + sksec->nlbl_state = NLBL_REQSKB; + } else + sksec->nlbl_state = NLBL_CONNLABELED; + break; + default: + /* note that we are failing to label the socket which could be + * a bad thing since it means traffic could leave the system + * without the desired labeling, however, all is not lost as + * we have a check in selinux_netlbl_inode_permission() to + * pick up the pieces that we might drop here because we can't + * return an error code */ + break; + } + +inet_conn_established_return: + netlbl_secattr_destroy(&secattr); + return; } /** @@ -398,7 +440,8 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock, struct netlbl_lsm_secattr secattr; if (level == IPPROTO_IP && optname == IP_OPTIONS && - sksec->nlbl_state == NLBL_LABELED) { + (sksec->nlbl_state == NLBL_LABELED || + sksec->nlbl_state == NLBL_CONNLABELED)) { netlbl_secattr_init(&secattr); lock_sock(sk); rc = netlbl_sock_getattr(sk, &secattr); @@ -410,3 +453,51 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock, return rc; } + +/** + * selinux_netlbl_socket_connect - Label a client-side socket on connect + * @sk: the socket to label + * @addr: the destination address + * + * Description: + * Attempt to label a connected socket with NetLabel using the given address. + * Returns zero values on success, negative values on failure. + * + */ +int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr) +{ + int rc; + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr secattr; + + if (sksec->nlbl_state != NLBL_REQSKB && + sksec->nlbl_state != NLBL_CONNLABELED) + return 0; + + netlbl_secattr_init(&secattr); + local_bh_disable(); + bh_lock_sock_nested(sk); + + /* connected sockets are allowed to disconnect when the address family + * is set to AF_UNSPEC, if that is what is happening we want to reset + * the socket */ + if (addr->sa_family == AF_UNSPEC) { + netlbl_sock_delattr(sk); + sksec->nlbl_state = NLBL_REQSKB; + rc = 0; + goto socket_connect_return; + } + rc = security_netlbl_sid_to_secattr(sksec->sid, &secattr); + if (rc != 0) + goto socket_connect_return; + rc = netlbl_conn_setattr(sk, addr, &secattr); + if (rc != 0) + goto socket_connect_return; + sksec->nlbl_state = NLBL_CONNLABELED; + +socket_connect_return: + bh_unlock_sock(sk); + local_bh_enable(); + netlbl_secattr_destroy(&secattr); + return rc; +} -- cgit v1.2.3-70-g09d2 From 6c5b3fc0147f79d714d2fe748b5869d7892ef2e7 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Oct 2008 10:16:33 -0400 Subject: selinux: Cache NetLabel secattrs in the socket's security struct Previous work enabled the use of address based NetLabel selectors, which while highly useful, brought the potential for additional per-packet overhead when used. This patch attempts to mitigate some of that overhead by caching the NetLabel security attribute struct within the SELinux socket security structure. This should help eliminate the need to recreate the NetLabel secattr structure for each packet resulting in less overhead. Signed-off-by: Paul Moore Acked-by: James Morris --- security/selinux/hooks.c | 1 + security/selinux/include/netlabel.h | 7 +++ security/selinux/include/objsec.h | 7 ++- security/selinux/netlabel.c | 115 +++++++++++++++++++++++++----------- 4 files changed, 91 insertions(+), 39 deletions(-) (limited to 'security/selinux/netlabel.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 632ac3e80a6..3aa811eba25 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -291,6 +291,7 @@ static void sk_free_security(struct sock *sk) struct sk_security_struct *ssec = sk->sk_security; sk->sk_security = NULL; + selinux_netlbl_sk_security_free(ssec); kfree(ssec); } diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h index 982bac0ac32..b913c8d0603 100644 --- a/security/selinux/include/netlabel.h +++ b/security/selinux/include/netlabel.h @@ -41,6 +41,7 @@ void selinux_netlbl_cache_invalidate(void); void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway); +void selinux_netlbl_sk_security_free(struct sk_security_struct *ssec); void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec, int family); @@ -77,6 +78,12 @@ static inline void selinux_netlbl_err(struct sk_buff *skb, return; } +static inline void selinux_netlbl_sk_security_free( + struct sk_security_struct *ssec) +{ + return; +} + static inline void selinux_netlbl_sk_security_reset( struct sk_security_struct *ssec, int family) diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index ad34787c6c0..f8be8d7fa26 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -109,9 +109,6 @@ struct netport_security_struct { }; struct sk_security_struct { - u32 sid; /* SID of this object */ - u32 peer_sid; /* SID of peer */ - u16 sclass; /* sock security class */ #ifdef CONFIG_NETLABEL enum { /* NetLabel state */ NLBL_UNSET = 0, @@ -120,7 +117,11 @@ struct sk_security_struct { NLBL_REQSKB, NLBL_CONNLABELED, } nlbl_state; + struct netlbl_lsm_secattr *nlbl_secattr; /* NetLabel sec attributes */ #endif + u32 sid; /* SID of this object */ + u32 peer_sid; /* SID of peer */ + u16 sclass; /* sock security class */ }; struct key_security_struct { diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index b22b7dafa0e..f58701a7b72 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -67,6 +67,38 @@ static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb, return rc; } +/** + * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr + * @sk: the socket + * + * Description: + * Generate the NetLabel security attributes for a socket, making full use of + * the socket's attribute cache. Returns a pointer to the security attributes + * on success, NULL on failure. + * + */ +static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk) +{ + int rc; + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr *secattr; + + if (sksec->nlbl_secattr != NULL) + return sksec->nlbl_secattr; + + secattr = netlbl_secattr_alloc(GFP_ATOMIC); + if (secattr == NULL) + return NULL; + rc = security_netlbl_sid_to_secattr(sksec->sid, secattr); + if (rc != 0) { + netlbl_secattr_free(secattr); + return NULL; + } + sksec->nlbl_secattr = secattr; + + return secattr; +} + /** * selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism * @sk: the socket to label @@ -80,17 +112,15 @@ static int selinux_netlbl_sock_setsid(struct sock *sk) { int rc; struct sk_security_struct *sksec = sk->sk_security; - struct netlbl_lsm_secattr secattr; + struct netlbl_lsm_secattr *secattr; if (sksec->nlbl_state != NLBL_REQUIRE) return 0; - netlbl_secattr_init(&secattr); - - rc = security_netlbl_sid_to_secattr(sksec->sid, &secattr); - if (rc != 0) - goto sock_setsid_return; - rc = netlbl_sock_setattr(sk, &secattr); + secattr = selinux_netlbl_sock_genattr(sk); + if (secattr == NULL) + return -ENOMEM; + rc = netlbl_sock_setattr(sk, secattr); switch (rc) { case 0: sksec->nlbl_state = NLBL_LABELED; @@ -101,8 +131,6 @@ static int selinux_netlbl_sock_setsid(struct sock *sk) break; } -sock_setsid_return: - netlbl_secattr_destroy(&secattr); return rc; } @@ -136,6 +164,20 @@ void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway) netlbl_skbuff_err(skb, error, gateway); } +/** + * selinux_netlbl_sk_security_free - Free the NetLabel fields + * @sssec: the sk_security_struct + * + * Description: + * Free all of the memory in the NetLabel fields of a sk_security_struct. + * + */ +void selinux_netlbl_sk_security_free(struct sk_security_struct *ssec) +{ + if (ssec->nlbl_secattr != NULL) + netlbl_secattr_free(ssec->nlbl_secattr); +} + /** * selinux_netlbl_sk_security_reset - Reset the NetLabel fields * @ssec: the sk_security_struct @@ -209,7 +251,8 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, u32 sid) { int rc; - struct netlbl_lsm_secattr secattr; + struct netlbl_lsm_secattr secattr_storage; + struct netlbl_lsm_secattr *secattr = NULL; struct sock *sk; /* if this is a locally generated packet check to see if it is already @@ -219,16 +262,21 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, struct sk_security_struct *sksec = sk->sk_security; if (sksec->nlbl_state != NLBL_REQSKB) return 0; + secattr = sksec->nlbl_secattr; + } + if (secattr == NULL) { + secattr = &secattr_storage; + netlbl_secattr_init(secattr); + rc = security_netlbl_sid_to_secattr(sid, secattr); + if (rc != 0) + goto skbuff_setsid_return; } - netlbl_secattr_init(&secattr); - rc = security_netlbl_sid_to_secattr(sid, &secattr); - if (rc != 0) - goto skbuff_setsid_return; - rc = netlbl_skbuff_setattr(skb, family, &secattr); + rc = netlbl_skbuff_setattr(skb, family, secattr); skbuff_setsid_return: - netlbl_secattr_destroy(&secattr); + if (secattr == &secattr_storage) + netlbl_secattr_destroy(secattr); return rc; } @@ -245,18 +293,18 @@ void selinux_netlbl_inet_conn_established(struct sock *sk, u16 family) { int rc; struct sk_security_struct *sksec = sk->sk_security; - struct netlbl_lsm_secattr secattr; + struct netlbl_lsm_secattr *secattr; struct inet_sock *sk_inet = inet_sk(sk); struct sockaddr_in addr; if (sksec->nlbl_state != NLBL_REQUIRE) return; - netlbl_secattr_init(&secattr); - if (security_netlbl_sid_to_secattr(sksec->sid, &secattr) != 0) - goto inet_conn_established_return; + secattr = selinux_netlbl_sock_genattr(sk); + if (secattr == NULL) + return; - rc = netlbl_sock_setattr(sk, &secattr); + rc = netlbl_sock_setattr(sk, secattr); switch (rc) { case 0: sksec->nlbl_state = NLBL_LABELED; @@ -266,13 +314,13 @@ void selinux_netlbl_inet_conn_established(struct sock *sk, u16 family) * labeling protocols */ if (family != PF_INET) { sksec->nlbl_state = NLBL_UNSET; - goto inet_conn_established_return; + return; } addr.sin_family = family; addr.sin_addr.s_addr = sk_inet->daddr; if (netlbl_conn_setattr(sk, (struct sockaddr *)&addr, - &secattr) != 0) { + secattr) != 0) { /* we failed to label the connected socket (could be * for a variety of reasons, the actual "why" isn't * important here) so we have to go to our backup plan, @@ -300,10 +348,6 @@ void selinux_netlbl_inet_conn_established(struct sock *sk, u16 family) * return an error code */ break; } - -inet_conn_established_return: - netlbl_secattr_destroy(&secattr); - return; } /** @@ -468,13 +512,12 @@ int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr) { int rc; struct sk_security_struct *sksec = sk->sk_security; - struct netlbl_lsm_secattr secattr; + struct netlbl_lsm_secattr *secattr; if (sksec->nlbl_state != NLBL_REQSKB && sksec->nlbl_state != NLBL_CONNLABELED) return 0; - netlbl_secattr_init(&secattr); local_bh_disable(); bh_lock_sock_nested(sk); @@ -487,17 +530,17 @@ int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr) rc = 0; goto socket_connect_return; } - rc = security_netlbl_sid_to_secattr(sksec->sid, &secattr); - if (rc != 0) + secattr = selinux_netlbl_sock_genattr(sk); + if (secattr == NULL) { + rc = -ENOMEM; goto socket_connect_return; - rc = netlbl_conn_setattr(sk, addr, &secattr); - if (rc != 0) - goto socket_connect_return; - sksec->nlbl_state = NLBL_CONNLABELED; + } + rc = netlbl_conn_setattr(sk, addr, secattr); + if (rc == 0) + sksec->nlbl_state = NLBL_CONNLABELED; socket_connect_return: bh_unlock_sock(sk); local_bh_enable(); - netlbl_secattr_destroy(&secattr); return rc; } -- cgit v1.2.3-70-g09d2