linux/security/smack/smackfs.c
Casey Schaufler 86812bb0de Smack: move label list initialization
A kernel with Smack enabled will fail if tmpfs has xattr support.

Move the initialization of predefined Smack label
list entries to the LSM initialization from the
smackfs setup. This became an issue when tmpfs
acquired xattr support, but was never correct.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-04-18 12:02:28 +10:00

1620 lines
37 KiB
C

/*
* Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
*
* 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
* the Free Software Foundation, version 2.
*
* Authors:
* Casey Schaufler <casey@schaufler-ca.com>
* Ahmed S. Darwish <darwish.07@gmail.com>
*
* Special thanks to the authors of selinuxfs.
*
* Karl MacMillan <kmacmillan@tresys.com>
* James Morris <jmorris@redhat.com>
*
*/
#include <linux/kernel.h>
#include <linux/vmalloc.h>
#include <linux/security.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>
#include <linux/seq_file.h>
#include <linux/ctype.h>
#include <linux/audit.h>
#include "smack.h"
/*
* smackfs pseudo filesystem.
*/
enum smk_inos {
SMK_ROOT_INO = 2,
SMK_LOAD = 3, /* load policy */
SMK_CIPSO = 4, /* load label -> CIPSO mapping */
SMK_DOI = 5, /* CIPSO DOI */
SMK_DIRECT = 6, /* CIPSO level indicating direct label */
SMK_AMBIENT = 7, /* internet ambient label */
SMK_NETLBLADDR = 8, /* single label hosts */
SMK_ONLYCAP = 9, /* the only "capable" label */
SMK_LOGGING = 10, /* logging */
SMK_LOAD_SELF = 11, /* task specific rules */
SMK_ACCESSES = 12, /* access policy */
};
/*
* List locks
*/
static DEFINE_MUTEX(smack_list_lock);
static DEFINE_MUTEX(smack_cipso_lock);
static DEFINE_MUTEX(smack_ambient_lock);
static DEFINE_MUTEX(smk_netlbladdr_lock);
/*
* This is the "ambient" label for network traffic.
* If it isn't somehow marked, use this.
* It can be reset via smackfs/ambient
*/
char *smack_net_ambient = smack_known_floor.smk_known;
/*
* This is the level in a CIPSO header that indicates a
* smack label is contained directly in the category set.
* It can be reset via smackfs/direct
*/
int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT;
/*
* Unless a process is running with this label even
* having CAP_MAC_OVERRIDE isn't enough to grant
* privilege to violate MAC policy. If no label is
* designated (the NULL case) capabilities apply to
* everyone. It is expected that the hat (^) label
* will be used if any label is used.
*/
char *smack_onlycap;
/*
* Certain IP addresses may be designated as single label hosts.
* Packets are sent there unlabeled, but only from tasks that
* can write to the specified label.
*/
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;
const char *smack_cipso_option = SMACK_CIPSO_OPTION;
/*
* Values for parsing cipso rules
* SMK_DIGITLEN: Length of a digit field in a rule.
* SMK_CIPSOMIN: Minimum possible cipso rule length.
* SMK_CIPSOMAX: Maximum possible cipso rule length.
*/
#define SMK_DIGITLEN 4
#define SMK_CIPSOMIN (SMK_LABELLEN + 2 * SMK_DIGITLEN)
#define SMK_CIPSOMAX (SMK_CIPSOMIN + SMACK_CIPSO_MAXCATNUM * SMK_DIGITLEN)
/*
* Values for parsing MAC rules
* SMK_ACCESS: Maximum possible combination of access permissions
* SMK_ACCESSLEN: Maximum length for a rule access field
* SMK_LOADLEN: Smack rule length
*/
#define SMK_OACCESS "rwxa"
#define SMK_ACCESS "rwxat"
#define SMK_OACCESSLEN (sizeof(SMK_OACCESS) - 1)
#define SMK_ACCESSLEN (sizeof(SMK_ACCESS) - 1)
#define SMK_OLOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_OACCESSLEN)
#define SMK_LOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSLEN)
/**
* smk_netlabel_audit_set - fill a netlbl_audit struct
* @nap: structure to fill
*/
static void smk_netlabel_audit_set(struct netlbl_audit *nap)
{
nap->loginuid = audit_get_loginuid(current);
nap->sessionid = audit_get_sessionid(current);
nap->secid = smack_to_secid(smk_of_current());
}
/*
* Values for parsing single label host rules
* "1.2.3.4 X"
* "192.168.138.129/32 abcdefghijklmnopqrstuvw"
*/
#define SMK_NETLBLADDRMIN 9
#define SMK_NETLBLADDRMAX 42
/**
* smk_set_access - add a rule to the rule list
* @srp: the new rule to add
* @rule_list: the list of rules
* @rule_lock: the rule list lock
*
* Looks through the current subject/object/access list for
* the subject/object pair and replaces the access that was
* there. If the pair isn't found add it with the specified
* access.
*
* Returns 1 if a rule was found to exist already, 0 if it is new
* Returns 0 if nothing goes wrong or -ENOMEM if it fails
* during the allocation of the new pair to add.
*/
static int smk_set_access(struct smack_rule *srp, struct list_head *rule_list,
struct mutex *rule_lock)
{
struct smack_rule *sp;
int found = 0;
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_object == srp->smk_object &&
sp->smk_subject == srp->smk_subject) {
found = 1;
sp->smk_access = srp->smk_access;
break;
}
}
if (found == 0)
list_add_rcu(&srp->list, rule_list);
mutex_unlock(rule_lock);
return found;
}
/**
* smk_parse_rule - parse Smack rule from load string
* @data: string to be parsed whose size is SMK_LOADLEN
* @rule: Smack rule
* @import: if non-zero, import labels
*/
static int smk_parse_rule(const char *data, struct smack_rule *rule, int import)
{
char smack[SMK_LABELLEN];
struct smack_known *skp;
if (import) {
rule->smk_subject = smk_import(data, 0);
if (rule->smk_subject == NULL)
return -1;
rule->smk_object = smk_import(data + SMK_LABELLEN, 0);
if (rule->smk_object == NULL)
return -1;
} else {
smk_parse_smack(data, 0, smack);
skp = smk_find_entry(smack);
if (skp == NULL)
return -1;
rule->smk_subject = skp->smk_known;
smk_parse_smack(data + SMK_LABELLEN, 0, smack);
skp = smk_find_entry(smack);
if (skp == NULL)
return -1;
rule->smk_object = skp->smk_known;
}
rule->smk_access = 0;
switch (data[SMK_LABELLEN + SMK_LABELLEN]) {
case '-':
break;
case 'r':
case 'R':
rule->smk_access |= MAY_READ;
break;
default:
return -1;
}
switch (data[SMK_LABELLEN + SMK_LABELLEN + 1]) {
case '-':
break;
case 'w':
case 'W':
rule->smk_access |= MAY_WRITE;
break;
default:
return -1;
}
switch (data[SMK_LABELLEN + SMK_LABELLEN + 2]) {
case '-':
break;
case 'x':
case 'X':
rule->smk_access |= MAY_EXEC;
break;
default:
return -1;
}
switch (data[SMK_LABELLEN + SMK_LABELLEN + 3]) {
case '-':
break;
case 'a':
case 'A':
rule->smk_access |= MAY_APPEND;
break;
default:
return -1;
}
switch (data[SMK_LABELLEN + SMK_LABELLEN + 4]) {
case '-':
break;
case 't':
case 'T':
rule->smk_access |= MAY_TRANSMUTE;
break;
default:
return -1;
}
return 0;
}
/**
* smk_write_load_list - write() for any /smack/load
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start - must be 0
* @rule_list: the list of rules to write to
* @rule_lock: lock for the rule list
*
* Get one smack access rule from above.
* The format is exactly:
* char subject[SMK_LABELLEN]
* char object[SMK_LABELLEN]
* char access[SMK_ACCESSLEN]
*
* writes must be SMK_LABELLEN+SMK_LABELLEN+SMK_ACCESSLEN bytes.
*/
static ssize_t smk_write_load_list(struct file *file, const char __user *buf,
size_t count, loff_t *ppos,
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.
* Enough data must be present.
*/
if (*ppos != 0)
return -EINVAL;
/*
* Minor hack for backward compatibility
*/
if (count < (SMK_OLOADLEN) || count > SMK_LOADLEN)
return -EINVAL;
data = kzalloc(SMK_LOADLEN, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
if (copy_from_user(data, buf, count) != 0) {
rc = -EFAULT;
goto out;
}
/*
* More on the minor hack for backward compatibility
*/
if (count == (SMK_OLOADLEN))
data[SMK_OLOADLEN] = '-';
rule = kzalloc(sizeof(*rule), GFP_KERNEL);
if (rule == NULL) {
rc = -ENOMEM;
goto out;
}
if (smk_parse_rule(data, rule, 1))
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;
/*
* If this is "load" as opposed to "load-self" and a new rule
* it needs to get added for reporting.
* smk_set_access returns true if there was already a rule
* for the subject/object pair, and false if it was new.
*/
if (load && !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);
out:
kfree(data);
return rc;
}
/*
* Core logic for smackfs seq list operations.
*/
static void *smk_seq_start(struct seq_file *s, loff_t *pos,
struct list_head *head)
{
struct list_head *list;
/*
* This is 0 the first time through.
*/
if (s->index == 0)
s->private = head;
if (s->private == NULL)
return NULL;
list = s->private;
if (list_empty(list))
return NULL;
if (s->index == 0)
return list->next;
return list;
}
static void *smk_seq_next(struct seq_file *s, void *v, loff_t *pos,
struct list_head *head)
{
struct list_head *list = v;
if (list_is_last(list, head)) {
s->private = NULL;
return NULL;
}
s->private = list->next;
return list->next;
}
static void smk_seq_stop(struct seq_file *s, void *v)
{
/* No-op */
}
/*
* Seq_file read operations for /smack/load
*/
static void *load_seq_start(struct seq_file *s, loff_t *pos)
{
return smk_seq_start(s, pos, &smack_rule_list);
}
static void *load_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
return smk_seq_next(s, v, pos, &smack_rule_list);
}
static int load_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
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);
seq_putc(s, ' ');
if (srp->smk_access & MAY_READ)
seq_putc(s, 'r');
if (srp->smk_access & MAY_WRITE)
seq_putc(s, 'w');
if (srp->smk_access & MAY_EXEC)
seq_putc(s, 'x');
if (srp->smk_access & MAY_APPEND)
seq_putc(s, 'a');
if (srp->smk_access & MAY_TRANSMUTE)
seq_putc(s, 't');
if (srp->smk_access == 0)
seq_putc(s, '-');
seq_putc(s, '\n');
return 0;
}
static const struct seq_operations load_seq_ops = {
.start = load_seq_start,
.next = load_seq_next,
.show = load_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_load - open() for /smack/load
* @inode: inode structure representing file
* @file: "load" file pointer
*
* For reading, use load_seq_* seq_file reading operations.
*/
static int smk_open_load(struct inode *inode, struct file *file)
{
return seq_open(file, &load_seq_ops);
}
/**
* smk_write_load - write() for /smack/load
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start - must be 0
*
*/
static ssize_t smk_write_load(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
/*
* Must have privilege.
* No partial writes.
* Enough data must be present.
*/
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
return smk_write_load_list(file, buf, count, ppos, NULL, NULL);
}
static const struct file_operations smk_load_ops = {
.open = smk_open_load,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_load,
.release = seq_release,
};
/**
* smk_cipso_doi - initialize the CIPSO domain
*/
static void smk_cipso_doi(void)
{
int rc;
struct cipso_v4_doi *doip;
struct netlbl_audit nai;
smk_netlabel_audit_set(&nai);
rc = netlbl_cfg_map_del(NULL, PF_INET, NULL, NULL, &nai);
if (rc != 0)
printk(KERN_WARNING "%s:%d remove rc = %d\n",
__func__, __LINE__, rc);
doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL);
if (doip == NULL)
panic("smack: Failed to initialize cipso DOI.\n");
doip->map.std = NULL;
doip->doi = smk_cipso_doi_value;
doip->type = CIPSO_V4_MAP_PASS;
doip->tags[0] = CIPSO_V4_TAG_RBITMAP;
for (rc = 1; rc < CIPSO_V4_TAG_MAXCNT; rc++)
doip->tags[rc] = CIPSO_V4_TAG_INVALID;
rc = netlbl_cfg_cipsov4_add(doip, &nai);
if (rc != 0) {
printk(KERN_WARNING "%s:%d cipso add rc = %d\n",
__func__, __LINE__, rc);
kfree(doip);
return;
}
rc = netlbl_cfg_cipsov4_map_add(doip->doi, NULL, NULL, NULL, &nai);
if (rc != 0) {
printk(KERN_WARNING "%s:%d map add rc = %d\n",
__func__, __LINE__, rc);
kfree(doip);
return;
}
}
/**
* smk_unlbl_ambient - initialize the unlabeled domain
* @oldambient: previous domain string
*/
static void smk_unlbl_ambient(char *oldambient)
{
int rc;
struct netlbl_audit nai;
smk_netlabel_audit_set(&nai);
if (oldambient != NULL) {
rc = netlbl_cfg_map_del(oldambient, PF_INET, NULL, NULL, &nai);
if (rc != 0)
printk(KERN_WARNING "%s:%d remove rc = %d\n",
__func__, __LINE__, rc);
}
rc = netlbl_cfg_unlbl_map_add(smack_net_ambient, PF_INET,
NULL, NULL, &nai);
if (rc != 0)
printk(KERN_WARNING "%s:%d add rc = %d\n",
__func__, __LINE__, rc);
}
/*
* Seq_file read operations for /smack/cipso
*/
static void *cipso_seq_start(struct seq_file *s, loff_t *pos)
{
return smk_seq_start(s, pos, &smack_known_list);
}
static void *cipso_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
return smk_seq_next(s, v, pos, &smack_known_list);
}
/*
* Print cipso labels in format:
* label level[/cat[,cat]]
*/
static int cipso_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smack_known *skp =
list_entry(list, struct smack_known, list);
struct smack_cipso *scp = skp->smk_cipso;
char *cbp;
char sep = '/';
int cat = 1;
int i;
unsigned char m;
if (scp == NULL)
return 0;
seq_printf(s, "%s %3d", (char *)&skp->smk_known, scp->smk_level);
cbp = scp->smk_catset;
for (i = 0; i < SMK_LABELLEN; i++)
for (m = 0x80; m != 0; m >>= 1) {
if (m & cbp[i]) {
seq_printf(s, "%c%d", sep, cat);
sep = ',';
}
cat++;
}
seq_putc(s, '\n');
return 0;
}
static const struct seq_operations cipso_seq_ops = {
.start = cipso_seq_start,
.next = cipso_seq_next,
.show = cipso_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_cipso - open() for /smack/cipso
* @inode: inode structure representing file
* @file: "cipso" file pointer
*
* Connect our cipso_seq_* operations with /smack/cipso
* file_operations
*/
static int smk_open_cipso(struct inode *inode, struct file *file)
{
return seq_open(file, &cipso_seq_ops);
}
/**
* smk_write_cipso - write() for /smack/cipso
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Accepts only one cipso rule per write call.
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_cipso(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct smack_known *skp;
struct smack_cipso *scp = NULL;
char mapcatset[SMK_LABELLEN];
int maplevel;
int cat;
int catlen;
ssize_t rc = -EINVAL;
char *data = NULL;
char *rule;
int ret;
int i;
/*
* Must have privilege.
* No partial writes.
* Enough data must be present.
*/
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (*ppos != 0)
return -EINVAL;
if (count < SMK_CIPSOMIN || count > SMK_CIPSOMAX)
return -EINVAL;
data = kzalloc(count + 1, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
if (copy_from_user(data, buf, count) != 0) {
rc = -EFAULT;
goto unlockedout;
}
/* labels cannot begin with a '-' */
if (data[0] == '-') {
rc = -EINVAL;
goto unlockedout;
}
data[count] = '\0';
rule = data;
/*
* Only allow one writer at a time. Writes should be
* quite rare and small in any case.
*/
mutex_lock(&smack_cipso_lock);
skp = smk_import_entry(rule, 0);
if (skp == NULL)
goto out;
rule += SMK_LABELLEN;
ret = sscanf(rule, "%d", &maplevel);
if (ret != 1 || maplevel > SMACK_CIPSO_MAXLEVEL)
goto out;
rule += SMK_DIGITLEN;
ret = sscanf(rule, "%d", &catlen);
if (ret != 1 || catlen > SMACK_CIPSO_MAXCATNUM)
goto out;
if (count != (SMK_CIPSOMIN + catlen * SMK_DIGITLEN))
goto out;
memset(mapcatset, 0, sizeof(mapcatset));
for (i = 0; i < catlen; i++) {
rule += SMK_DIGITLEN;
ret = sscanf(rule, "%d", &cat);
if (ret != 1 || cat > SMACK_CIPSO_MAXCATVAL)
goto out;
smack_catset_bit(cat, mapcatset);
}
if (skp->smk_cipso == NULL) {
scp = kzalloc(sizeof(struct smack_cipso), GFP_KERNEL);
if (scp == NULL) {
rc = -ENOMEM;
goto out;
}
}
spin_lock_bh(&skp->smk_cipsolock);
if (scp == NULL)
scp = skp->smk_cipso;
else
skp->smk_cipso = scp;
scp->smk_level = maplevel;
memcpy(scp->smk_catset, mapcatset, sizeof(mapcatset));
spin_unlock_bh(&skp->smk_cipsolock);
rc = count;
out:
mutex_unlock(&smack_cipso_lock);
unlockedout:
kfree(data);
return rc;
}
static const struct file_operations smk_cipso_ops = {
.open = smk_open_cipso,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_cipso,
.release = seq_release,
};
/*
* Seq_file read operations for /smack/netlabel
*/
static void *netlbladdr_seq_start(struct seq_file *s, loff_t *pos)
{
return smk_seq_start(s, pos, &smk_netlbladdr_list);
}
static void *netlbladdr_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
return smk_seq_next(s, v, pos, &smk_netlbladdr_list);
}
#define BEBITS (sizeof(__be32) * 8)
/*
* Print host/label pairs
*/
static int netlbladdr_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smk_netlbladdr *skp =
list_entry(list, struct smk_netlbladdr, list);
unsigned char *hp = (char *) &skp->smk_host.sin_addr.s_addr;
int maskn;
u32 temp_mask = be32_to_cpu(skp->smk_mask.s_addr);
for (maskn = 0; temp_mask; temp_mask <<= 1, maskn++);
seq_printf(s, "%u.%u.%u.%u/%d %s\n",
hp[0], hp[1], hp[2], hp[3], maskn, skp->smk_label);
return 0;
}
static const struct seq_operations netlbladdr_seq_ops = {
.start = netlbladdr_seq_start,
.next = netlbladdr_seq_next,
.show = netlbladdr_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_netlbladdr - open() for /smack/netlabel
* @inode: inode structure representing file
* @file: "netlabel" file pointer
*
* Connect our netlbladdr_seq_* operations with /smack/netlabel
* file_operations
*/
static int smk_open_netlbladdr(struct inode *inode, struct file *file)
{
return seq_open(file, &netlbladdr_seq_ops);
}
/**
* smk_netlbladdr_insert
* @new : netlabel to insert
*
* This helper insert netlabel in the smack_netlbladdrs list
* sorted by netmask length (longest to smallest)
* locked by &smk_netlbladdr_lock in smk_write_netlbladdr
*
*/
static void smk_netlbladdr_insert(struct smk_netlbladdr *new)
{
struct smk_netlbladdr *m, *m_next;
if (list_empty(&smk_netlbladdr_list)) {
list_add_rcu(&new->list, &smk_netlbladdr_list);
return;
}
m = list_entry_rcu(smk_netlbladdr_list.next,
struct smk_netlbladdr, list);
/* the comparison '>' is a bit hacky, but works */
if (new->smk_mask.s_addr > m->smk_mask.s_addr) {
list_add_rcu(&new->list, &smk_netlbladdr_list);
return;
}
list_for_each_entry_rcu(m, &smk_netlbladdr_list, list) {
if (list_is_last(&m->list, &smk_netlbladdr_list)) {
list_add_rcu(&new->list, &m->list);
return;
}
m_next = list_entry_rcu(m->list.next,
struct smk_netlbladdr, list);
if (new->smk_mask.s_addr > m_next->smk_mask.s_addr) {
list_add_rcu(&new->list, &m->list);
return;
}
}
}
/**
* smk_write_netlbladdr - write() for /smack/netlabel
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Accepts only one netlbladdr per write call.
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct smk_netlbladdr *skp;
struct sockaddr_in newname;
char smack[SMK_LABELLEN];
char *sp;
char data[SMK_NETLBLADDRMAX + 1];
char *host = (char *)&newname.sin_addr.s_addr;
int rc;
struct netlbl_audit audit_info;
struct in_addr mask;
unsigned int m;
int found;
u32 mask_bits = (1<<31);
__be32 nsa;
u32 temp_mask;
/*
* Must have privilege.
* No partial writes.
* Enough data must be present.
* "<addr/mask, as a.b.c.d/e><space><label>"
* "<addr, as a.b.c.d><space><label>"
*/
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (*ppos != 0)
return -EINVAL;
if (count < SMK_NETLBLADDRMIN || count > SMK_NETLBLADDRMAX)
return -EINVAL;
if (copy_from_user(data, buf, count) != 0)
return -EFAULT;
data[count] = '\0';
rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%d %s",
&host[0], &host[1], &host[2], &host[3], &m, smack);
if (rc != 6) {
rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd %s",
&host[0], &host[1], &host[2], &host[3], smack);
if (rc != 5)
return -EINVAL;
m = BEBITS;
}
if (m > BEBITS)
return -EINVAL;
/* if smack begins with '-', its an option, don't import it */
if (smack[0] != '-') {
sp = smk_import(smack, 0);
if (sp == NULL)
return -EINVAL;
} else {
/* check known options */
if (strcmp(smack, smack_cipso_option) == 0)
sp = (char *)smack_cipso_option;
else
return -EINVAL;
}
for (temp_mask = 0; m > 0; m--) {
temp_mask |= mask_bits;
mask_bits >>= 1;
}
mask.s_addr = cpu_to_be32(temp_mask);
newname.sin_addr.s_addr &= mask.s_addr;
/*
* Only allow one writer at a time. Writes should be
* quite rare and small in any case.
*/
mutex_lock(&smk_netlbladdr_lock);
nsa = newname.sin_addr.s_addr;
/* try to find if the prefix is already in the list */
found = 0;
list_for_each_entry_rcu(skp, &smk_netlbladdr_list, list) {
if (skp->smk_host.sin_addr.s_addr == nsa &&
skp->smk_mask.s_addr == mask.s_addr) {
found = 1;
break;
}
}
smk_netlabel_audit_set(&audit_info);
if (found == 0) {
skp = kzalloc(sizeof(*skp), GFP_KERNEL);
if (skp == NULL)
rc = -ENOMEM;
else {
rc = 0;
skp->smk_host.sin_addr.s_addr = newname.sin_addr.s_addr;
skp->smk_mask.s_addr = mask.s_addr;
skp->smk_label = sp;
smk_netlbladdr_insert(skp);
}
} else {
/* we delete the unlabeled entry, only if the previous label
* wasn't the special CIPSO option */
if (skp->smk_label != smack_cipso_option)
rc = netlbl_cfg_unlbl_static_del(&init_net, NULL,
&skp->smk_host.sin_addr, &skp->smk_mask,
PF_INET, &audit_info);
else
rc = 0;
skp->smk_label = sp;
}
/*
* Now tell netlabel about the single label nature of
* this host so that incoming packets get labeled.
* but only if we didn't get the special CIPSO option
*/
if (rc == 0 && sp != smack_cipso_option)
rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
&skp->smk_host.sin_addr, &skp->smk_mask, PF_INET,
smack_to_secid(skp->smk_label), &audit_info);
if (rc == 0)
rc = count;
mutex_unlock(&smk_netlbladdr_lock);
return rc;
}
static const struct file_operations smk_netlbladdr_ops = {
.open = smk_open_netlbladdr,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_netlbladdr,
.release = seq_release,
};
/**
* smk_read_doi - read() for /smack/doi
* @filp: file pointer, not actually used
* @buf: where to put the result
* @count: maximum to send along
* @ppos: where to start
*
* Returns number of bytes read or error code, as appropriate
*/
static ssize_t smk_read_doi(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char temp[80];
ssize_t rc;
if (*ppos != 0)
return 0;
sprintf(temp, "%d", smk_cipso_doi_value);
rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
return rc;
}
/**
* smk_write_doi - write() for /smack/doi
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_doi(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char temp[80];
int i;
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (count >= sizeof(temp) || count == 0)
return -EINVAL;
if (copy_from_user(temp, buf, count) != 0)
return -EFAULT;
temp[count] = '\0';
if (sscanf(temp, "%d", &i) != 1)
return -EINVAL;
smk_cipso_doi_value = i;
smk_cipso_doi();
return count;
}
static const struct file_operations smk_doi_ops = {
.read = smk_read_doi,
.write = smk_write_doi,
.llseek = default_llseek,
};
/**
* smk_read_direct - read() for /smack/direct
* @filp: file pointer, not actually used
* @buf: where to put the result
* @count: maximum to send along
* @ppos: where to start
*
* Returns number of bytes read or error code, as appropriate
*/
static ssize_t smk_read_direct(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char temp[80];
ssize_t rc;
if (*ppos != 0)
return 0;
sprintf(temp, "%d", smack_cipso_direct);
rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
return rc;
}
/**
* smk_write_direct - write() for /smack/direct
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_direct(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char temp[80];
int i;
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (count >= sizeof(temp) || count == 0)
return -EINVAL;
if (copy_from_user(temp, buf, count) != 0)
return -EFAULT;
temp[count] = '\0';
if (sscanf(temp, "%d", &i) != 1)
return -EINVAL;
smack_cipso_direct = i;
return count;
}
static const struct file_operations smk_direct_ops = {
.read = smk_read_direct,
.write = smk_write_direct,
.llseek = default_llseek,
};
/**
* smk_read_ambient - read() for /smack/ambient
* @filp: file pointer, not actually used
* @buf: where to put the result
* @cn: maximum to send along
* @ppos: where to start
*
* Returns number of bytes read or error code, as appropriate
*/
static ssize_t smk_read_ambient(struct file *filp, char __user *buf,
size_t cn, loff_t *ppos)
{
ssize_t rc;
int asize;
if (*ppos != 0)
return 0;
/*
* Being careful to avoid a problem in the case where
* smack_net_ambient gets changed in midstream.
*/
mutex_lock(&smack_ambient_lock);
asize = strlen(smack_net_ambient) + 1;
if (cn >= asize)
rc = simple_read_from_buffer(buf, cn, ppos,
smack_net_ambient, asize);
else
rc = -EINVAL;
mutex_unlock(&smack_ambient_lock);
return rc;
}
/**
* smk_write_ambient - write() for /smack/ambient
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_ambient(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char in[SMK_LABELLEN];
char *oldambient;
char *smack;
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (count >= SMK_LABELLEN)
return -EINVAL;
if (copy_from_user(in, buf, count) != 0)
return -EFAULT;
smack = smk_import(in, count);
if (smack == NULL)
return -EINVAL;
mutex_lock(&smack_ambient_lock);
oldambient = smack_net_ambient;
smack_net_ambient = smack;
smk_unlbl_ambient(oldambient);
mutex_unlock(&smack_ambient_lock);
return count;
}
static const struct file_operations smk_ambient_ops = {
.read = smk_read_ambient,
.write = smk_write_ambient,
.llseek = default_llseek,
};
/**
* smk_read_onlycap - read() for /smack/onlycap
* @filp: file pointer, not actually used
* @buf: where to put the result
* @cn: maximum to send along
* @ppos: where to start
*
* Returns number of bytes read or error code, as appropriate
*/
static ssize_t smk_read_onlycap(struct file *filp, char __user *buf,
size_t cn, loff_t *ppos)
{
char *smack = "";
ssize_t rc = -EINVAL;
int asize;
if (*ppos != 0)
return 0;
if (smack_onlycap != NULL)
smack = smack_onlycap;
asize = strlen(smack) + 1;
if (cn >= asize)
rc = simple_read_from_buffer(buf, cn, ppos, smack, asize);
return rc;
}
/**
* smk_write_onlycap - write() for /smack/onlycap
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char in[SMK_LABELLEN];
char *sp = smk_of_task(current->cred->security);
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
/*
* This can be done using smk_access() but is done
* explicitly for clarity. The smk_access() implementation
* would use smk_access(smack_onlycap, MAY_WRITE)
*/
if (smack_onlycap != NULL && smack_onlycap != sp)
return -EPERM;
if (count >= SMK_LABELLEN)
return -EINVAL;
if (copy_from_user(in, buf, count) != 0)
return -EFAULT;
/*
* Should the null string be passed in unset the onlycap value.
* This seems like something to be careful with as usually
* smk_import only expects to return NULL for errors. It
* is usually the case that a nullstring or "\n" would be
* bad to pass to smk_import but in fact this is useful here.
*/
smack_onlycap = smk_import(in, count);
return count;
}
static const struct file_operations smk_onlycap_ops = {
.read = smk_read_onlycap,
.write = smk_write_onlycap,
.llseek = default_llseek,
};
/**
* smk_read_logging - read() for /smack/logging
* @filp: file pointer, not actually used
* @buf: where to put the result
* @cn: maximum to send along
* @ppos: where to start
*
* Returns number of bytes read or error code, as appropriate
*/
static ssize_t smk_read_logging(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char temp[32];
ssize_t rc;
if (*ppos != 0)
return 0;
sprintf(temp, "%d\n", log_policy);
rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
return rc;
}
/**
* smk_write_logging - write() for /smack/logging
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_logging(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char temp[32];
int i;
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (count >= sizeof(temp) || count == 0)
return -EINVAL;
if (copy_from_user(temp, buf, count) != 0)
return -EFAULT;
temp[count] = '\0';
if (sscanf(temp, "%d", &i) != 1)
return -EINVAL;
if (i < 0 || i > 3)
return -EINVAL;
log_policy = i;
return count;
}
static const struct file_operations smk_logging_ops = {
.read = smk_read_logging,
.write = smk_write_logging,
.llseek = default_llseek,
};
/*
* Seq_file read operations for /smack/load-self
*/
static void *load_self_seq_start(struct seq_file *s, loff_t *pos)
{
struct task_smack *tsp = current_security();
return smk_seq_start(s, pos, &tsp->smk_rules);
}
static void *load_self_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
struct task_smack *tsp = current_security();
return smk_seq_next(s, v, pos, &tsp->smk_rules);
}
static int load_self_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smack_rule *srp =
list_entry(list, struct smack_rule, list);
seq_printf(s, "%s %s", (char *)srp->smk_subject,
(char *)srp->smk_object);
seq_putc(s, ' ');
if (srp->smk_access & MAY_READ)
seq_putc(s, 'r');
if (srp->smk_access & MAY_WRITE)
seq_putc(s, 'w');
if (srp->smk_access & MAY_EXEC)
seq_putc(s, 'x');
if (srp->smk_access & MAY_APPEND)
seq_putc(s, 'a');
if (srp->smk_access & MAY_TRANSMUTE)
seq_putc(s, 't');
if (srp->smk_access == 0)
seq_putc(s, '-');
seq_putc(s, '\n');
return 0;
}
static const struct seq_operations load_self_seq_ops = {
.start = load_self_seq_start,
.next = load_self_seq_next,
.show = load_self_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_load_self - open() for /smack/load-self
* @inode: inode structure representing file
* @file: "load" file pointer
*
* For reading, use load_seq_* seq_file reading operations.
*/
static int smk_open_load_self(struct inode *inode, struct file *file)
{
return seq_open(file, &load_self_seq_ops);
}
/**
* smk_write_load_self - write() for /smack/load-self
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start - must be 0
*
*/
static ssize_t smk_write_load_self(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct task_smack *tsp = current_security();
return smk_write_load_list(file, buf, count, ppos, &tsp->smk_rules,
&tsp->smk_rules_lock);
}
static const struct file_operations smk_load_self_ops = {
.open = smk_open_load_self,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_load_self,
.release = seq_release,
};
/**
* smk_write_access - handle access check transaction
* @file: file pointer
* @buf: data from user space
* @count: bytes sent
* @ppos: where to start - must be 0
*/
static ssize_t smk_write_access(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct smack_rule rule;
char *data;
int res;
data = simple_transaction_get(file, buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
if (count < SMK_LOADLEN || smk_parse_rule(data, &rule, 0))
return -EINVAL;
res = smk_access(rule.smk_subject, rule.smk_object, rule.smk_access,
NULL);
data[0] = res == 0 ? '1' : '0';
data[1] = '\0';
simple_transaction_set(file, 2);
return SMK_LOADLEN;
}
static const struct file_operations smk_access_ops = {
.write = smk_write_access,
.read = simple_transaction_read,
.release = simple_transaction_release,
.llseek = generic_file_llseek,
};
/**
* smk_fill_super - fill the /smackfs superblock
* @sb: the empty superblock
* @data: unused
* @silent: unused
*
* Fill in the well known entries for /smack
*
* Returns 0 on success, an error code on failure
*/
static int smk_fill_super(struct super_block *sb, void *data, int silent)
{
int rc;
struct inode *root_inode;
static struct tree_descr smack_files[] = {
[SMK_LOAD] = {
"load", &smk_load_ops, S_IRUGO|S_IWUSR},
[SMK_CIPSO] = {
"cipso", &smk_cipso_ops, S_IRUGO|S_IWUSR},
[SMK_DOI] = {
"doi", &smk_doi_ops, S_IRUGO|S_IWUSR},
[SMK_DIRECT] = {
"direct", &smk_direct_ops, S_IRUGO|S_IWUSR},
[SMK_AMBIENT] = {
"ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR},
[SMK_NETLBLADDR] = {
"netlabel", &smk_netlbladdr_ops, S_IRUGO|S_IWUSR},
[SMK_ONLYCAP] = {
"onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR},
[SMK_LOGGING] = {
"logging", &smk_logging_ops, S_IRUGO|S_IWUSR},
[SMK_LOAD_SELF] = {
"load-self", &smk_load_self_ops, S_IRUGO|S_IWUGO},
[SMK_ACCESSES] = {
"access", &smk_access_ops, S_IRUGO|S_IWUGO},
/* last one */
{""}
};
rc = simple_fill_super(sb, SMACK_MAGIC, smack_files);
if (rc != 0) {
printk(KERN_ERR "%s failed %d while creating inodes\n",
__func__, rc);
return rc;
}
root_inode = sb->s_root->d_inode;
root_inode->i_security = new_inode_smack(smack_known_floor.smk_known);
return 0;
}
/**
* smk_mount - get the smackfs superblock
* @fs_type: passed along without comment
* @flags: passed along without comment
* @dev_name: passed along without comment
* @data: passed along without comment
*
* Just passes everything along.
*
* Returns what the lower level code does.
*/
static struct dentry *smk_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_single(fs_type, flags, data, smk_fill_super);
}
static struct file_system_type smk_fs_type = {
.name = "smackfs",
.mount = smk_mount,
.kill_sb = kill_litter_super,
};
static struct vfsmount *smackfs_mount;
/**
* init_smk_fs - get the smackfs superblock
*
* register the smackfs
*
* Do not register smackfs if Smack wasn't enabled
* on boot. We can not put this method normally under the
* smack_init() code path since the security subsystem get
* initialized before the vfs caches.
*
* Returns true if we were not chosen on boot or if
* we were chosen and filesystem registration succeeded.
*/
static int __init init_smk_fs(void)
{
int err;
if (!security_module_enable(&smack_ops))
return 0;
err = register_filesystem(&smk_fs_type);
if (!err) {
smackfs_mount = kern_mount(&smk_fs_type);
if (IS_ERR(smackfs_mount)) {
printk(KERN_ERR "smackfs: could not mount!\n");
err = PTR_ERR(smackfs_mount);
smackfs_mount = NULL;
}
}
smk_cipso_doi();
smk_unlbl_ambient(NULL);
return err;
}
__initcall(init_smk_fs);