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Message-ID: <4E80D1D1.3010300@schaufler-ca.com>
Date: Mon, 26 Sep 2011 12:26:09 -0700
From: Casey Schaufler <casey@...aufler-ca.com>
To: Casey Schaufler <casey@...aufler-ca.com>
CC: LKLM <linux-kernel@...r.kernel.org>,
LSM <linux-security-module@...r.kernel.org>,
Jarkko Sakkinen <jarkko.sakkinen@...el.com>,
Andi Kleen <andi@...stfloor.org>
Subject: Re: [PATCH] Smack: Rule list lookup performance
On 9/20/2011 12:24 PM, Casey Schaufler wrote:
> This patch is targeted for the smack-next tree.
>
> Smack access checks suffer from two significant performance
> issues. In cases where there are large numbers of rules the
> search of the single list of rules is wasteful. Comparing the
> string values of the smack labels is less efficient than a
> numeric comparison would.
>
> These changes take advantage of the Smack label list, which
> maintains the mapping of Smack labels to secids and optional
> CIPSO labels. Because the labels are kept perpetually, an
> access check can be done strictly based on the address of the
> label in the list without ever looking at the label itself.
> Rather than keeping one global list of rules the rules with
> a particular subject label can be based off of that label
> list entry. The access check need never look at entries that
> do not use the current subject label.
>
> This requires that packets coming off the network with
> CIPSO direct Smack labels that have never been seen before
> be treated carefully. The only case where they could be
> delivered is where the receiving socket has an IPIN star
> label, so that case is explicitly addressed.
>
> On a system with 39,800 rules (200 labels in all permutations)
> a system with this patch runs an access speed test in 5% of
> the time of the old version. That should be a best case
> improvement. If all of the rules are associated with the
> same subject label and all of the accesses are for processes
> with that label (unlikely) the improvement is about 30%.
>
> Signed-off-by: Casey Schaufler <casey@...aufler-ca.com>
Applied to gitorious.org/smack-next/kernel.git
>
> ---
> security/smack/smack.h | 18 ++++--
> security/smack/smack_access.c | 113 ++++++++++++++++++------------------
> security/smack/smack_lsm.c | 126 +++++++++++++++++++++++++----------------
> security/smack/smackfs.c | 84 ++++++++++++++++++++++++---
> 4 files changed, 220 insertions(+), 121 deletions(-)
>
> diff --git a/security/smack/smack.h b/security/smack/smack.h
> index 2b6c6a5..174d3be 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -41,9 +41,9 @@ struct superblock_smack {
> };
>
> struct socket_smack {
> - char *smk_out; /* outbound label */
> - char *smk_in; /* inbound label */
> - char smk_packet[SMK_LABELLEN]; /* TCP peer label */
> + char *smk_out; /* outbound label */
> + char *smk_in; /* inbound label */
> + char *smk_packet; /* TCP peer label */
> };
>
> /*
> @@ -116,13 +116,19 @@ struct smk_netlbladdr {
> * If there is a cipso value associated with the label it
> * gets stored here, too. This will most likely be rare as
> * the cipso direct mapping in used internally.
> + *
> + * Keep the access rules for this subject label here so that
> + * the entire set of rules does not need to be examined every
> + * time.
> */
> struct smack_known {
> struct list_head list;
> char smk_known[SMK_LABELLEN];
> u32 smk_secid;
> struct smack_cipso *smk_cipso;
> - spinlock_t smk_cipsolock; /* for changing cipso map */
> + spinlock_t smk_cipsolock; /* for changing cipso map */
> + struct list_head smk_rules; /* access rules */
> + struct mutex smk_rules_lock; /* lock for the rules */
> };
>
> /*
> @@ -201,10 +207,11 @@ int smk_access_entry(char *, char *, struct list_head *);
> int smk_access(char *, char *, int, struct smk_audit_info *);
> int smk_curacc(char *, u32, struct smk_audit_info *);
> int smack_to_cipso(const char *, struct smack_cipso *);
> -void smack_from_cipso(u32, char *, char *);
> +char *smack_from_cipso(u32, char *);
> char *smack_from_secid(const u32);
> char *smk_import(const char *, int);
> struct smack_known *smk_import_entry(const char *, int);
> +struct smack_known *smk_find_entry(const char *);
> u32 smack_to_secid(const char *);
>
> /*
> @@ -223,7 +230,6 @@ extern struct smack_known smack_known_star;
> extern struct smack_known smack_known_web;
>
> extern struct list_head smack_known_list;
> -extern struct list_head smack_rule_list;
> extern struct list_head smk_netlbladdr_list;
>
> extern struct security_operations smack_ops;
> diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
> index 9637e10..a885f62 100644
> --- a/security/smack/smack_access.c
> +++ b/security/smack/smack_access.c
> @@ -77,14 +77,19 @@ int log_policy = SMACK_AUDIT_DENIED;
> * entry is found returns -ENOENT.
> *
> * NOTE:
> - * Even though Smack labels are usually shared on smack_list
> - * labels that come in off the network can't be imported
> - * and added to the list for locking reasons.
> *
> - * Therefore, it is necessary to check the contents of the labels,
> - * not just the pointer values. Of course, in most cases the labels
> - * will be on the list, so checking the pointers may be a worthwhile
> - * optimization.
> + * Earlier versions of this function allowed for labels that
> + * were not on the label list. This was done to allow for
> + * labels to come over the network that had never been seen
> + * before on this host. Unless the receiving socket has the
> + * star label this will always result in a failure check. The
> + * star labeled socket case is now handled in the networking
> + * hooks so there is no case where the label is not on the
> + * label list. Checking to see if the address of two labels
> + * is the same is now a reliable test.
> + *
> + * Do the object check first because that is more
> + * likely to differ.
> */
> int smk_access_entry(char *subject_label, char *object_label,
> struct list_head *rule_list)
> @@ -93,13 +98,10 @@ int smk_access_entry(char *subject_label, char *object_label,
> struct smack_rule *srp;
>
> list_for_each_entry_rcu(srp, rule_list, list) {
> - if (srp->smk_subject == subject_label ||
> - strcmp(srp->smk_subject, subject_label) == 0) {
> - if (srp->smk_object == object_label ||
> - strcmp(srp->smk_object, object_label) == 0) {
> - may = srp->smk_access;
> - break;
> - }
> + if (srp->smk_object == object_label &&
> + srp->smk_subject == subject_label) {
> + may = srp->smk_access;
> + break;
> }
> }
>
> @@ -117,18 +119,12 @@ int smk_access_entry(char *subject_label, char *object_label,
> * access rule list and returns 0 if the access is permitted,
> * non zero otherwise.
> *
> - * Even though Smack labels are usually shared on smack_list
> - * labels that come in off the network can't be imported
> - * and added to the list for locking reasons.
> - *
> - * Therefore, it is necessary to check the contents of the labels,
> - * not just the pointer values. Of course, in most cases the labels
> - * will be on the list, so checking the pointers may be a worthwhile
> - * optimization.
> + * Smack labels are shared on smack_list
> */
> int smk_access(char *subject_label, char *object_label, int request,
> struct smk_audit_info *a)
> {
> + struct smack_known *skp;
> int may = MAY_NOT;
> int rc = 0;
>
> @@ -137,8 +133,7 @@ int smk_access(char *subject_label, char *object_label, int request,
> *
> * A star subject can't access any object.
> */
> - if (subject_label == smack_known_star.smk_known ||
> - strcmp(subject_label, smack_known_star.smk_known) == 0) {
> + if (subject_label == smack_known_star.smk_known) {
> rc = -EACCES;
> goto out_audit;
> }
> @@ -148,33 +143,27 @@ int smk_access(char *subject_label, char *object_label, int request,
> * An internet subject can access any object.
> */
> if (object_label == smack_known_web.smk_known ||
> - subject_label == smack_known_web.smk_known ||
> - strcmp(object_label, smack_known_web.smk_known) == 0 ||
> - strcmp(subject_label, smack_known_web.smk_known) == 0)
> + subject_label == smack_known_web.smk_known)
> goto out_audit;
> /*
> * A star object can be accessed by any subject.
> */
> - if (object_label == smack_known_star.smk_known ||
> - strcmp(object_label, smack_known_star.smk_known) == 0)
> + if (object_label == smack_known_star.smk_known)
> goto out_audit;
> /*
> * An object can be accessed in any way by a subject
> * with the same label.
> */
> - if (subject_label == object_label ||
> - strcmp(subject_label, object_label) == 0)
> + if (subject_label == object_label)
> goto out_audit;
> /*
> * A hat subject can read any object.
> * A floor object can be read by any subject.
> */
> if ((request & MAY_ANYREAD) == request) {
> - if (object_label == smack_known_floor.smk_known ||
> - strcmp(object_label, smack_known_floor.smk_known) == 0)
> + if (object_label == smack_known_floor.smk_known)
> goto out_audit;
> - if (subject_label == smack_known_hat.smk_known ||
> - strcmp(subject_label, smack_known_hat.smk_known) == 0)
> + if (subject_label == smack_known_hat.smk_known)
> goto out_audit;
> }
> /*
> @@ -184,8 +173,9 @@ int smk_access(char *subject_label, char *object_label, int request,
> * good. A negative response from smk_access_entry()
> * indicates there is no entry for this pair.
> */
> + skp = smk_find_entry(subject_label);
> rcu_read_lock();
> - may = smk_access_entry(subject_label, object_label, &smack_rule_list);
> + may = smk_access_entry(subject_label, object_label, &skp->smk_rules);
> rcu_read_unlock();
>
> if (may > 0 && (request & may) == request)
> @@ -344,6 +334,25 @@ void smack_log(char *subject_label, char *object_label, int request,
> static DEFINE_MUTEX(smack_known_lock);
>
> /**
> + * smk_find_entry - find a label on the list, return the list entry
> + * @string: a text string that might be a Smack label
> + *
> + * Returns a pointer to the entry in the label list that
> + * matches the passed string.
> + */
> +struct smack_known *smk_find_entry(const char *string)
> +{
> + struct smack_known *skp;
> +
> + list_for_each_entry_rcu(skp, &smack_known_list, list) {
> + if (strncmp(skp->smk_known, string, SMK_MAXLEN) == 0)
> + return skp;
> + }
> +
> + return NULL;
> +}
> +
> +/**
> * smk_import_entry - import a label, return the list entry
> * @string: a text string that might be a Smack label
> * @len: the maximum size, or zero if it is NULL terminated.
> @@ -378,21 +387,17 @@ struct smack_known *smk_import_entry(const char *string, int len)
>
> mutex_lock(&smack_known_lock);
>
> - found = 0;
> - list_for_each_entry_rcu(skp, &smack_known_list, list) {
> - if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
> - found = 1;
> - break;
> - }
> - }
> + skp = smk_find_entry(smack);
>
> - if (found == 0) {
> + if (skp == NULL) {
> skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL);
> if (skp != NULL) {
> strncpy(skp->smk_known, smack, SMK_MAXLEN);
> skp->smk_secid = smack_next_secid++;
> skp->smk_cipso = NULL;
> + INIT_LIST_HEAD(&skp->smk_rules);
> spin_lock_init(&skp->smk_cipsolock);
> + mutex_init(&skp->smk_rules_lock);
> /*
> * Make sure that the entry is actually
> * filled before putting it on the list.
> @@ -480,19 +485,12 @@ u32 smack_to_secid(const char *smack)
> * smack_from_cipso - find the Smack label associated with a CIPSO option
> * @level: Bell & LaPadula level from the network
> * @cp: Bell & LaPadula categories from the network
> - * @result: where to put the Smack value
> *
> * This is a simple lookup in the label table.
> *
> - * This is an odd duck as far as smack handling goes in that
> - * it sends back a copy of the smack label rather than a pointer
> - * to the master list. This is done because it is possible for
> - * a foreign host to send a smack label that is new to this
> - * machine and hence not on the list. That would not be an
> - * issue except that adding an entry to the master list can't
> - * be done at that point.
> + * Return the matching label from the label list or NULL.
> */
> -void smack_from_cipso(u32 level, char *cp, char *result)
> +char *smack_from_cipso(u32 level, char *cp)
> {
> struct smack_known *kp;
> char *final = NULL;
> @@ -509,12 +507,13 @@ void smack_from_cipso(u32 level, char *cp, char *result)
> final = kp->smk_known;
>
> spin_unlock_bh(&kp->smk_cipsolock);
> +
> + if (final != NULL)
> + break;
> }
> rcu_read_unlock();
> - if (final == NULL)
> - final = smack_known_huh.smk_known;
> - strncpy(result, final, SMK_MAXLEN);
> - return;
> +
> + return final;
> }
>
> /**
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index b9c5e14..fb91516 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -516,6 +516,8 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
> const struct qstr *qstr, char **name,
> void **value, size_t *len)
> {
> + struct smack_known *skp;
> + char *csp = smk_of_current();
> char *isp = smk_of_inode(inode);
> char *dsp = smk_of_inode(dir);
> int may;
> @@ -527,8 +529,9 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
> }
>
> if (value) {
> + skp = smk_find_entry(csp);
> rcu_read_lock();
> - may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list);
> + may = smk_access_entry(csp, dsp, &skp->smk_rules);
> rcu_read_unlock();
>
> /*
> @@ -1138,6 +1141,7 @@ static int smack_file_mmap(struct file *file,
> unsigned long flags, unsigned long addr,
> unsigned long addr_only)
> {
> + struct smack_known *skp;
> struct smack_rule *srp;
> struct task_smack *tsp;
> char *sp;
> @@ -1170,6 +1174,7 @@ static int smack_file_mmap(struct file *file,
>
> tsp = current_security();
> sp = smk_of_current();
> + skp = smk_find_entry(sp);
> rc = 0;
>
> rcu_read_lock();
> @@ -1177,15 +1182,8 @@ static int smack_file_mmap(struct file *file,
> * For each Smack rule associated with the subject
> * label verify that the SMACK64MMAP also has access
> * to that rule's object label.
> - *
> - * Because neither of the labels comes
> - * from the networking code it is sufficient
> - * to compare pointers.
> */
> - list_for_each_entry_rcu(srp, &smack_rule_list, list) {
> - if (srp->smk_subject != sp)
> - continue;
> -
> + list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
> osmack = srp->smk_object;
> /*
> * Matching labels always allows access.
> @@ -1214,7 +1212,8 @@ static int smack_file_mmap(struct file *file,
> * If there isn't one a SMACK64MMAP subject
> * can't have as much access as current.
> */
> - mmay = smk_access_entry(msmack, osmack, &smack_rule_list);
> + skp = smk_find_entry(msmack);
> + mmay = smk_access_entry(msmack, osmack, &skp->smk_rules);
> if (mmay == -ENOENT) {
> rc = -EACCES;
> break;
> @@ -1711,7 +1710,7 @@ 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_packet[0] = '\0';
> + ssp->smk_packet = NULL;
>
> sk->sk_security = ssp;
>
> @@ -2813,16 +2812,17 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
> return smack_netlabel_send(sock->sk, sip);
> }
>
> -
> /**
> * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
> * @sap: netlabel secattr
> - * @sip: where to put the result
> + * @ssp: socket security information
> *
> - * Copies a smack label into sip
> + * Returns a pointer to a Smack label found on the label list.
> */
> -static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
> +static char *smack_from_secattr(struct netlbl_lsm_secattr *sap,
> + struct socket_smack *ssp)
> {
> + struct smack_known *skp;
> char smack[SMK_LABELLEN];
> char *sp;
> int pcat;
> @@ -2852,15 +2852,43 @@ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
> * we are already done. WeeHee.
> */
> if (sap->attr.mls.lvl == smack_cipso_direct) {
> - memcpy(sip, smack, SMK_MAXLEN);
> - return;
> + /*
> + * The label sent is usually on the label list.
> + *
> + * If it is not we may still want to allow the
> + * delivery.
> + *
> + * If the recipient is accepting all packets
> + * because it is using the star ("*") label
> + * for SMACK64IPIN provide the web ("@") label
> + * so that a directed response will succeed.
> + * This is not very correct from a MAC point
> + * of view, but gets around the problem that
> + * locking prevents adding the newly discovered
> + * label to the list.
> + * The case where the recipient is not using
> + * the star label should obviously fail.
> + * The easy way to do this is to provide the
> + * star label as the subject label.
> + */
> + skp = smk_find_entry(smack);
> + if (skp != NULL)
> + return skp->smk_known;
> + if (ssp != NULL &&
> + ssp->smk_in == smack_known_star.smk_known)
> + return smack_known_web.smk_known;
> + return smack_known_star.smk_known;
> }
> /*
> * Look it up in the supplied table if it is not
> * a direct mapping.
> */
> - smack_from_cipso(sap->attr.mls.lvl, smack, sip);
> - return;
> + sp = smack_from_cipso(sap->attr.mls.lvl, smack);
> + if (sp != NULL)
> + return sp;
> + if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known)
> + return smack_known_web.smk_known;
> + return smack_known_star.smk_known;
> }
> if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
> /*
> @@ -2875,16 +2903,14 @@ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
> * secid is from a fallback.
> */
> BUG_ON(sp == NULL);
> - strncpy(sip, sp, SMK_MAXLEN);
> - return;
> + return sp;
> }
> /*
> * Without guidance regarding the smack value
> * for the packet fall back on the network
> * ambient value.
> */
> - strncpy(sip, smack_net_ambient, SMK_MAXLEN);
> - return;
> + return smack_net_ambient;
> }
>
> /**
> @@ -2898,7 +2924,6 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
> {
> struct netlbl_lsm_secattr secattr;
> struct socket_smack *ssp = sk->sk_security;
> - char smack[SMK_LABELLEN];
> char *csp;
> int rc;
> struct smk_audit_info ad;
> @@ -2911,10 +2936,9 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
> netlbl_secattr_init(&secattr);
>
> rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
> - if (rc == 0) {
> - smack_from_secattr(&secattr, smack);
> - csp = smack;
> - } else
> + if (rc == 0)
> + csp = smack_from_secattr(&secattr, ssp);
> + else
> csp = smack_net_ambient;
>
> netlbl_secattr_destroy(&secattr);
> @@ -2951,15 +2975,19 @@ static int smack_socket_getpeersec_stream(struct socket *sock,
> int __user *optlen, unsigned len)
> {
> struct socket_smack *ssp;
> - int slen;
> + char *rcp = "";
> + int slen = 1;
> int rc = 0;
>
> ssp = sock->sk->sk_security;
> - slen = strlen(ssp->smk_packet) + 1;
> + if (ssp->smk_packet != NULL) {
> + rcp = ssp->smk_packet;
> + slen = strlen(rcp) + 1;
> + }
>
> if (slen > len)
> rc = -ERANGE;
> - else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
> + else if (copy_to_user(optval, rcp, slen) != 0)
> rc = -EFAULT;
>
> if (put_user(slen, optlen) != 0)
> @@ -2982,8 +3010,8 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
>
> {
> struct netlbl_lsm_secattr secattr;
> - struct socket_smack *sp;
> - char smack[SMK_LABELLEN];
> + struct socket_smack *ssp = NULL;
> + char *sp;
> int family = PF_UNSPEC;
> u32 s = 0; /* 0 is the invalid secid */
> int rc;
> @@ -2998,17 +3026,19 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
> family = sock->sk->sk_family;
>
> if (family == PF_UNIX) {
> - sp = sock->sk->sk_security;
> - s = smack_to_secid(sp->smk_out);
> + ssp = sock->sk->sk_security;
> + s = smack_to_secid(ssp->smk_out);
> } else if (family == PF_INET || family == PF_INET6) {
> /*
> * Translate what netlabel gave us.
> */
> + if (sock != NULL && sock->sk != NULL)
> + ssp = sock->sk->sk_security;
> netlbl_secattr_init(&secattr);
> rc = netlbl_skbuff_getattr(skb, family, &secattr);
> if (rc == 0) {
> - smack_from_secattr(&secattr, smack);
> - s = smack_to_secid(smack);
> + sp = smack_from_secattr(&secattr, ssp);
> + s = smack_to_secid(sp);
> }
> netlbl_secattr_destroy(&secattr);
> }
> @@ -3056,7 +3086,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
> struct netlbl_lsm_secattr secattr;
> struct sockaddr_in addr;
> struct iphdr *hdr;
> - char smack[SMK_LABELLEN];
> + char *sp;
> int rc;
> struct smk_audit_info ad;
>
> @@ -3067,9 +3097,9 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
> netlbl_secattr_init(&secattr);
> rc = netlbl_skbuff_getattr(skb, family, &secattr);
> if (rc == 0)
> - smack_from_secattr(&secattr, smack);
> + sp = smack_from_secattr(&secattr, ssp);
> else
> - strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
> + sp = smack_known_huh.smk_known;
> netlbl_secattr_destroy(&secattr);
>
> #ifdef CONFIG_AUDIT
> @@ -3082,7 +3112,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
> * 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, &ad);
> + rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad);
> if (rc != 0)
> return rc;
>
> @@ -3090,7 +3120,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
> * 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);
> + req->peer_secid = smack_to_secid(sp);
>
> /*
> * We need to decide if we want to label the incoming connection here
> @@ -3103,7 +3133,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
> if (smack_host_label(&addr) == NULL) {
> rcu_read_unlock();
> netlbl_secattr_init(&secattr);
> - smack_to_secattr(smack, &secattr);
> + smack_to_secattr(sp, &secattr);
> rc = netlbl_req_setattr(req, &secattr);
> netlbl_secattr_destroy(&secattr);
> } else {
> @@ -3125,13 +3155,11 @@ 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';
> + if (req->peer_secid != 0)
> + ssp->smk_packet = smack_from_secid(req->peer_secid);
> + else
> + ssp->smk_packet = NULL;
> }
>
> /*
> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
> index f4c28ee..76e520b 100644
> --- a/security/smack/smackfs.c
> +++ b/security/smack/smackfs.c
> @@ -86,6 +86,16 @@ char *smack_onlycap;
> */
>
> LIST_HEAD(smk_netlbladdr_list);
> +
> +/*
> + * Rule lists are maintained for each label.
> + * This master list is just for reading /smack/load.
> + */
> +struct smack_master_list {
> + struct list_head list;
> + struct smack_rule *smk_rule;
> +};
> +
> LIST_HEAD(smack_rule_list);
>
> static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
> @@ -93,7 +103,10 @@ static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
> const char *smack_cipso_option = SMACK_CIPSO_OPTION;
>
>
> +#define SEQ_READ_FINISHED ((loff_t)-1)
> +/*
> #define SEQ_READ_FINISHED 1
> +*/
>
> /*
> * Values for parsing cipso rules
> @@ -160,9 +173,13 @@ static int smk_set_access(struct smack_rule *srp, struct list_head *rule_list,
>
> mutex_lock(rule_lock);
>
> + /*
> + * Because the object label is less likely to match
> + * than the subject label check it first
> + */
> list_for_each_entry_rcu(sp, rule_list, list) {
> - if (sp->smk_subject == srp->smk_subject &&
> - sp->smk_object == srp->smk_object) {
> + if (sp->smk_object == srp->smk_object &&
> + sp->smk_subject == srp->smk_subject) {
> found = 1;
> sp->smk_access = srp->smk_access;
> break;
> @@ -273,9 +290,12 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf,
> struct list_head *rule_list,
> struct mutex *rule_lock)
> {
> + struct smack_master_list *smlp;
> + struct smack_known *skp;
> struct smack_rule *rule;
> char *data;
> int rc = -EINVAL;
> + int load = 0;
>
> /*
> * No partial writes.
> @@ -313,13 +333,27 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf,
> if (smk_parse_rule(data, rule))
> goto out_free_rule;
>
> + if (rule_list == NULL) {
> + load = 1;
> + skp = smk_find_entry(rule->smk_subject);
> + rule_list = &skp->smk_rules;
> + rule_lock = &skp->smk_rules_lock;
> + }
> +
> rc = count;
> /*
> * smk_set_access returns true if there was already a rule
> * for the subject/object pair, and false if it was new.
> */
> - if (!smk_set_access(rule, rule_list, rule_lock))
> + if (!smk_set_access(rule, rule_list, rule_lock)) {
> + smlp = kzalloc(sizeof(*smlp), GFP_KERNEL);
> + if (smlp != NULL) {
> + smlp->smk_rule = rule;
> + list_add_rcu(&smlp->list, &smack_rule_list);
> + } else
> + rc = -ENOMEM;
> goto out;
> + }
>
> out_free_rule:
> kfree(rule);
> @@ -335,11 +369,24 @@ out:
>
> static void *load_seq_start(struct seq_file *s, loff_t *pos)
> {
> - if (*pos == SEQ_READ_FINISHED)
> + struct list_head *list;
> +
> + /*
> + * This is 0 the first time through.
> + */
> + if (s->index == 0)
> + s->private = &smack_rule_list;
> +
> + if (s->private == NULL)
> return NULL;
> - if (list_empty(&smack_rule_list))
> +
> + list = s->private;
> + if (list_empty(list))
> return NULL;
> - return smack_rule_list.next;
> +
> + if (s->index == 0)
> + return list->next;
> + return list;
> }
>
> static void *load_seq_next(struct seq_file *s, void *v, loff_t *pos)
> @@ -347,17 +394,19 @@ static void *load_seq_next(struct seq_file *s, void *v, loff_t *pos)
> struct list_head *list = v;
>
> if (list_is_last(list, &smack_rule_list)) {
> - *pos = SEQ_READ_FINISHED;
> + s->private = NULL;
> return NULL;
> }
> + s->private = list->next;
> return list->next;
> }
>
> static int load_seq_show(struct seq_file *s, void *v)
> {
> struct list_head *list = v;
> - struct smack_rule *srp =
> - list_entry(list, struct smack_rule, list);
> + struct smack_master_list *smlp =
> + list_entry(list, struct smack_master_list, list);
> + struct smack_rule *srp = smlp->smk_rule;
>
> seq_printf(s, "%s %s", (char *)srp->smk_subject,
> (char *)srp->smk_object);
> @@ -426,8 +475,11 @@ static ssize_t smk_write_load(struct file *file, const char __user *buf,
> if (!capable(CAP_MAC_ADMIN))
> return -EPERM;
>
> +/*
> return smk_write_load_list(file, buf, count, ppos, &smack_rule_list,
> &smack_list_lock);
> +*/
> + return smk_write_load_list(file, buf, count, ppos, NULL, NULL);
> }
>
> static const struct file_operations smk_load_ops = {
> @@ -1588,6 +1640,20 @@ static int __init init_smk_fs(void)
> smk_cipso_doi();
> smk_unlbl_ambient(NULL);
>
> + mutex_init(&smack_known_floor.smk_rules_lock);
> + mutex_init(&smack_known_hat.smk_rules_lock);
> + mutex_init(&smack_known_huh.smk_rules_lock);
> + mutex_init(&smack_known_invalid.smk_rules_lock);
> + mutex_init(&smack_known_star.smk_rules_lock);
> + mutex_init(&smack_known_web.smk_rules_lock);
> +
> + INIT_LIST_HEAD(&smack_known_floor.smk_rules);
> + INIT_LIST_HEAD(&smack_known_hat.smk_rules);
> + INIT_LIST_HEAD(&smack_known_huh.smk_rules);
> + INIT_LIST_HEAD(&smack_known_invalid.smk_rules);
> + INIT_LIST_HEAD(&smack_known_star.smk_rules);
> + INIT_LIST_HEAD(&smack_known_web.smk_rules);
> +
> return err;
> }
>
>
>
--
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