android_kernel_xiaomi_sm8350/security/smack/smackfs.c
Sergio Luis 81ea714bf1 smackfs: check for allocation failures in smk_set_access()
smackfs: check for allocation failures in smk_set_access()

 While adding a new subject/object pair to smack_list, smk_set_access()
 didn't check the return of kzalloc().

 This patch changes smk_set_access() to return 0 or -ENOMEM, based on
 kzalloc()'s return. It also updates its caller, smk_write_load(), to
 check for smk_set_access()'s return, given it is no longer a void
 return function.

 Signed-off-by: Sergio Luis <sergio@larces.uece.br>
 To: Casey Schaufler <casey@schaufler-ca.com>
 Cc: Ahmed S. Darwish <darwish.07@gmail.com>
 Cc: LSM <linux-security-module@vger.kernel.org>
 Cc: LKLM <linux-kernel@vger.kernel.org>

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2008-12-25 12:14:55 +11:00

1108 lines
24 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 <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_NLTYPE = 8, /* label scheme to use by default */
SMK_ONLYCAP = 9, /* the only "capable" label */
};
/*
* List locks
*/
static DEFINE_MUTEX(smack_list_lock);
static DEFINE_MUTEX(smack_cipso_lock);
static DEFINE_MUTEX(smack_ambient_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 default packet marking scheme for network traffic.
* It can be reset via smackfs/nltype
*/
int smack_net_nltype = NETLBL_NLTYPE_CIPSOV4;
/*
* 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;
static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
struct smk_list_entry *smack_list;
#define SEQ_READ_FINISHED 1
/*
* 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_ACCESS "rwxa"
#define SMK_ACCESSLEN (sizeof(SMK_ACCESS) - 1)
#define SMK_LOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSLEN)
/*
* Seq_file read operations for /smack/load
*/
static void *load_seq_start(struct seq_file *s, loff_t *pos)
{
if (*pos == SEQ_READ_FINISHED)
return NULL;
return smack_list;
}
static void *load_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
struct smk_list_entry *skp = ((struct smk_list_entry *) v)->smk_next;
if (skp == NULL)
*pos = SEQ_READ_FINISHED;
return skp;
}
static int load_seq_show(struct seq_file *s, void *v)
{
struct smk_list_entry *slp = (struct smk_list_entry *) v;
struct smack_rule *srp = &slp->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 == 0)
seq_putc(s, '-');
seq_putc(s, '\n');
return 0;
}
static void load_seq_stop(struct seq_file *s, void *v)
{
/* No-op */
}
static struct seq_operations load_seq_ops = {
.start = load_seq_start,
.next = load_seq_next,
.show = load_seq_show,
.stop = load_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_set_access - add a rule to the rule list
* @srp: the new rule to add
*
* 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 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 smk_list_entry *sp;
struct smk_list_entry *newp;
int ret = 0;
mutex_lock(&smack_list_lock);
for (sp = smack_list; sp != NULL; sp = sp->smk_next)
if (sp->smk_rule.smk_subject == srp->smk_subject &&
sp->smk_rule.smk_object == srp->smk_object) {
sp->smk_rule.smk_access = srp->smk_access;
break;
}
if (sp == NULL) {
newp = kzalloc(sizeof(struct smk_list_entry), GFP_KERNEL);
if (newp == NULL) {
ret = -ENOMEM;
goto out;
}
newp->smk_rule = *srp;
newp->smk_next = smack_list;
smack_list = newp;
}
out:
mutex_unlock(&smack_list_lock);
return ret;
}
/**
* smk_write_load - write() for /smack/load
* @filp: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start - must be 0
*
* 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(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct smack_rule rule;
char *data;
int rc = -EINVAL;
/*
* 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_LOADLEN)
return -EINVAL;
data = kzalloc(count, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
if (copy_from_user(data, buf, count) != 0) {
rc = -EFAULT;
goto out;
}
rule.smk_subject = smk_import(data, 0);
if (rule.smk_subject == NULL)
goto out;
rule.smk_object = smk_import(data + SMK_LABELLEN, 0);
if (rule.smk_object == NULL)
goto out;
rule.smk_access = 0;
switch (data[SMK_LABELLEN + SMK_LABELLEN]) {
case '-':
break;
case 'r':
case 'R':
rule.smk_access |= MAY_READ;
break;
default:
goto out;
}
switch (data[SMK_LABELLEN + SMK_LABELLEN + 1]) {
case '-':
break;
case 'w':
case 'W':
rule.smk_access |= MAY_WRITE;
break;
default:
goto out;
}
switch (data[SMK_LABELLEN + SMK_LABELLEN + 2]) {
case '-':
break;
case 'x':
case 'X':
rule.smk_access |= MAY_EXEC;
break;
default:
goto out;
}
switch (data[SMK_LABELLEN + SMK_LABELLEN + 3]) {
case '-':
break;
case 'a':
case 'A':
rule.smk_access |= MAY_READ;
break;
default:
goto out;
}
rc = smk_set_access(&rule);
if (!rc)
rc = count;
out:
kfree(data);
return rc;
}
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 audit_info;
audit_info.loginuid = audit_get_loginuid(current);
audit_info.sessionid = audit_get_sessionid(current);
audit_info.secid = smack_to_secid(current_security());
rc = netlbl_cfg_map_del(NULL, &audit_info);
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_map(doip, NULL, &audit_info);
if (rc != 0) {
printk(KERN_WARNING "%s:%d add rc = %d\n",
__func__, __LINE__, rc);
kfree(doip);
}
}
/**
* smk_unlbl_ambient - initialize the unlabeled domain
*/
static void smk_unlbl_ambient(char *oldambient)
{
int rc;
struct netlbl_audit audit_info;
audit_info.loginuid = audit_get_loginuid(current);
audit_info.sessionid = audit_get_sessionid(current);
audit_info.secid = smack_to_secid(current_security());
if (oldambient != NULL) {
rc = netlbl_cfg_map_del(oldambient, &audit_info);
if (rc != 0)
printk(KERN_WARNING "%s:%d remove rc = %d\n",
__func__, __LINE__, rc);
}
rc = netlbl_cfg_unlbl_add_map(smack_net_ambient, &audit_info);
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)
{
if (*pos == SEQ_READ_FINISHED)
return NULL;
return smack_known;
}
static void *cipso_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
struct smack_known *skp = ((struct smack_known *) v)->smk_next;
/*
* Omit labels with no associated cipso value
*/
while (skp != NULL && !skp->smk_cipso)
skp = skp->smk_next;
if (skp == NULL)
*pos = SEQ_READ_FINISHED;
return skp;
}
/*
* Print cipso labels in format:
* label level[/cat[,cat]]
*/
static int cipso_seq_show(struct seq_file *s, void *v)
{
struct smack_known *skp = (struct smack_known *) v;
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 void cipso_seq_stop(struct seq_file *s, void *v)
{
/* No-op */
}
static struct seq_operations cipso_seq_ops = {
.start = cipso_seq_start,
.stop = cipso_seq_stop,
.next = cipso_seq_next,
.show = cipso_seq_show,
};
/**
* 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
* @filp: 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;
}
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,
};
/**
* 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
* @filp: 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,
};
/**
* 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
* @filp: 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,
};
/**
* 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
* @filp: 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,
};
/**
* 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
* @filp: 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 = 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,
};
struct option_names {
int o_number;
char *o_name;
char *o_alias;
};
static struct option_names netlbl_choices[] = {
{ NETLBL_NLTYPE_RIPSO,
NETLBL_NLTYPE_RIPSO_NAME, "ripso" },
{ NETLBL_NLTYPE_CIPSOV4,
NETLBL_NLTYPE_CIPSOV4_NAME, "cipsov4" },
{ NETLBL_NLTYPE_CIPSOV4,
NETLBL_NLTYPE_CIPSOV4_NAME, "cipso" },
{ NETLBL_NLTYPE_CIPSOV6,
NETLBL_NLTYPE_CIPSOV6_NAME, "cipsov6" },
{ NETLBL_NLTYPE_UNLABELED,
NETLBL_NLTYPE_UNLABELED_NAME, "unlabeled" },
};
/**
* smk_read_nltype - read() for /smack/nltype
* @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_nltype(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char bound[40];
ssize_t rc;
int i;
if (count < SMK_LABELLEN)
return -EINVAL;
if (*ppos != 0)
return 0;
sprintf(bound, "unknown");
for (i = 0; i < ARRAY_SIZE(netlbl_choices); i++)
if (smack_net_nltype == netlbl_choices[i].o_number) {
sprintf(bound, "%s", netlbl_choices[i].o_name);
break;
}
rc = simple_read_from_buffer(buf, count, ppos, bound, strlen(bound));
return rc;
}
/**
* smk_write_nltype - write() for /smack/nltype
* @filp: 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_nltype(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char bound[40];
char *cp;
int i;
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (count >= 40)
return -EINVAL;
if (copy_from_user(bound, buf, count) != 0)
return -EFAULT;
bound[count] = '\0';
cp = strchr(bound, ' ');
if (cp != NULL)
*cp = '\0';
cp = strchr(bound, '\n');
if (cp != NULL)
*cp = '\0';
for (i = 0; i < ARRAY_SIZE(netlbl_choices); i++)
if (strcmp(bound, netlbl_choices[i].o_name) == 0 ||
strcmp(bound, netlbl_choices[i].o_alias) == 0) {
smack_net_nltype = netlbl_choices[i].o_number;
return count;
}
/*
* Not a valid choice.
*/
return -EINVAL;
}
static const struct file_operations smk_nltype_ops = {
.read = smk_read_nltype,
.write = smk_write_nltype,
};
/**
* 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_NLTYPE] =
{"nltype", &smk_nltype_ops, S_IRUGO|S_IWUSR},
[SMK_ONLYCAP] =
{"onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR},
/* 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_get_sb - 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
* @mnt: passed along without comment
*
* Just passes everything along.
*
* Returns what the lower level code does.
*/
static int smk_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
struct vfsmount *mnt)
{
return get_sb_single(fs_type, flags, data, smk_fill_super, mnt);
}
static struct file_system_type smk_fs_type = {
.name = "smackfs",
.get_sb = smk_get_sb,
.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);