diff options
Diffstat (limited to 'security/smack')
| -rw-r--r-- | security/smack/Kconfig | 10 | ||||
| -rw-r--r-- | security/smack/Makefile | 7 | ||||
| -rw-r--r-- | security/smack/smack.h | 220 | ||||
| -rw-r--r-- | security/smack/smack_access.c | 356 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 2518 | ||||
| -rw-r--r-- | security/smack/smackfs.c | 981 |
6 files changed, 4092 insertions, 0 deletions
diff --git a/security/smack/Kconfig b/security/smack/Kconfig new file mode 100644 index 000000000000..603b08784341 --- /dev/null +++ b/security/smack/Kconfig @@ -0,0 +1,10 @@ +config SECURITY_SMACK + bool "Simplified Mandatory Access Control Kernel Support" + depends on NETLABEL && SECURITY_NETWORK + default n + help + This selects the Simplified Mandatory Access Control Kernel. + Smack is useful for sensitivity, integrity, and a variety + of other mandatory security schemes. + If you are unsure how to answer this question, answer N. + diff --git a/security/smack/Makefile b/security/smack/Makefile new file mode 100644 index 000000000000..67a63aaec827 --- /dev/null +++ b/security/smack/Makefile @@ -0,0 +1,7 @@ +# +# Makefile for the SMACK LSM +# + +obj-$(CONFIG_SECURITY_SMACK) := smack.o + +smack-y := smack_lsm.o smack_access.o smackfs.o diff --git a/security/smack/smack.h b/security/smack/smack.h new file mode 100644 index 000000000000..a21a0e907ab3 --- /dev/null +++ b/security/smack/smack.h @@ -0,0 +1,220 @@ +/* + * 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. + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + * + */ + +#ifndef _SECURITY_SMACK_H +#define _SECURITY_SMACK_H + +#include <linux/capability.h> +#include <linux/spinlock.h> +#include <net/netlabel.h> + +/* + * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is + * bigger than can be used, and 24 is the next lower multiple + * of 8, and there are too many issues if there isn't space set + * aside for the terminating null byte. + */ +#define SMK_MAXLEN 23 +#define SMK_LABELLEN (SMK_MAXLEN+1) + +/* + * How many kinds of access are there? + * Here's your answer. + */ +#define SMK_ACCESSDASH '-' +#define SMK_ACCESSLOW "rwxa" +#define SMK_ACCESSKINDS (sizeof(SMK_ACCESSLOW) - 1) + +struct superblock_smack { + char *smk_root; + char *smk_floor; + char *smk_hat; + char *smk_default; + int smk_initialized; + spinlock_t smk_sblock; /* for initialization */ +}; + +struct socket_smack { + char *smk_out; /* outbound label */ + char *smk_in; /* inbound label */ + char smk_packet[SMK_LABELLEN]; /* TCP peer label */ +}; + +/* + * Inode smack data + */ +struct inode_smack { + char *smk_inode; /* label of the fso */ + struct mutex smk_lock; /* initialization lock */ + int smk_flags; /* smack inode flags */ +}; + +#define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ + +/* + * A label access rule. + */ +struct smack_rule { + char *smk_subject; + char *smk_object; + int smk_access; +}; + +/* + * An entry in the table of permitted label accesses. + */ +struct smk_list_entry { + struct smk_list_entry *smk_next; + struct smack_rule smk_rule; +}; + +/* + * An entry in the table mapping smack values to + * CIPSO level/category-set values. + */ +struct smack_cipso { + int smk_level; + char smk_catset[SMK_LABELLEN]; +}; + +/* + * This is the repository for labels seen so that it is + * not necessary to keep allocating tiny chuncks of memory + * and so that they can be shared. + * + * Labels are never modified in place. Anytime a label + * is imported (e.g. xattrset on a file) the list is checked + * for it and it is added if it doesn't exist. The address + * is passed out in either case. Entries are added, but + * never deleted. + * + * Since labels are hanging around anyway it doesn't + * hurt to maintain a secid for those awkward situations + * where kernel components that ought to use LSM independent + * interfaces don't. The secid should go away when all of + * these components have been repaired. + * + * 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. + */ +struct smack_known { + struct smack_known *smk_next; + char smk_known[SMK_LABELLEN]; + u32 smk_secid; + struct smack_cipso *smk_cipso; + spinlock_t smk_cipsolock; /* for changing cipso map */ +}; + +/* + * Mount options + */ +#define SMK_FSDEFAULT "smackfsdef=" +#define SMK_FSFLOOR "smackfsfloor=" +#define SMK_FSHAT "smackfshat=" +#define SMK_FSROOT "smackfsroot=" + +/* + * xattr names + */ +#define XATTR_SMACK_SUFFIX "SMACK64" +#define XATTR_SMACK_IPIN "SMACK64IPIN" +#define XATTR_SMACK_IPOUT "SMACK64IPOUT" +#define XATTR_NAME_SMACK XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX +#define XATTR_NAME_SMACKIPIN XATTR_SECURITY_PREFIX XATTR_SMACK_IPIN +#define XATTR_NAME_SMACKIPOUT XATTR_SECURITY_PREFIX XATTR_SMACK_IPOUT + +/* + * smackfs macic number + */ +#define SMACK_MAGIC 0x43415d53 /* "SMAC" */ + +/* + * A limit on the number of entries in the lists + * makes some of the list administration easier. + */ +#define SMACK_LIST_MAX 10000 + +/* + * CIPSO defaults. + */ +#define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ +#define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ +#define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */ +#define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ +#define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */ + +/* + * Just to make the common cases easier to deal with + */ +#define MAY_ANY (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) +#define MAY_ANYREAD (MAY_READ | MAY_EXEC) +#define MAY_ANYWRITE (MAY_WRITE | MAY_APPEND) +#define MAY_READWRITE (MAY_READ | MAY_WRITE) +#define MAY_NOT 0 + +/* + * These functions are in smack_lsm.c + */ +struct inode_smack *new_inode_smack(char *); + +/* + * These functions are in smack_access.c + */ +int smk_access(char *, char *, int); +int smk_curacc(char *, u32); +int smack_to_cipso(const char *, struct smack_cipso *); +void smack_from_cipso(u32, char *, char *); +char *smack_from_secid(const u32); +char *smk_import(const char *, int); +struct smack_known *smk_import_entry(const char *, int); +u32 smack_to_secid(const char *); + +/* + * Shared data. + */ +extern int smack_cipso_direct; +extern int smack_net_nltype; +extern char *smack_net_ambient; + +extern struct smack_known *smack_known; +extern struct smack_known smack_known_floor; +extern struct smack_known smack_known_hat; +extern struct smack_known smack_known_huh; +extern struct smack_known smack_known_invalid; +extern struct smack_known smack_known_star; +extern struct smack_known smack_known_unset; + +extern struct smk_list_entry *smack_list; + +/* + * Stricly for CIPSO level manipulation. + * Set the category bit number in a smack label sized buffer. + */ +static inline void smack_catset_bit(int cat, char *catsetp) +{ + if (cat > SMK_LABELLEN * 8) + return; + + catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); +} + +/* + * Present a pointer to the smack label in an inode blob. + */ +static inline char *smk_of_inode(const struct inode *isp) +{ + struct inode_smack *sip = isp->i_security; + return sip->smk_inode; +} + +#endif /* _SECURITY_SMACK_H */ diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c new file mode 100644 index 000000000000..f6b5f6eed6dd --- /dev/null +++ b/security/smack/smack_access.c @@ -0,0 +1,356 @@ +/* + * 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. + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + * + */ + +#include <linux/types.h> +#include <linux/fs.h> +#include <linux/sched.h> +#include "smack.h" + +struct smack_known smack_known_unset = { + .smk_next = NULL, + .smk_known = "UNSET", + .smk_secid = 1, + .smk_cipso = NULL, +}; + +struct smack_known smack_known_huh = { + .smk_next = &smack_known_unset, + .smk_known = "?", + .smk_secid = 2, + .smk_cipso = NULL, +}; + +struct smack_known smack_known_hat = { + .smk_next = &smack_known_huh, + .smk_known = "^", + .smk_secid = 3, + .smk_cipso = NULL, +}; + +struct smack_known smack_known_star = { + .smk_next = &smack_known_hat, + .smk_known = "*", + .smk_secid = 4, + .smk_cipso = NULL, +}; + +struct smack_known smack_known_floor = { + .smk_next = &smack_known_star, + .smk_known = "_", + .smk_secid = 5, + .smk_cipso = NULL, +}; + +struct smack_known smack_known_invalid = { + .smk_next = &smack_known_floor, + .smk_known = "", + .smk_secid = 6, + .smk_cipso = NULL, +}; + +struct smack_known *smack_known = &smack_known_invalid; + +/* + * The initial value needs to be bigger than any of the + * known values above. + */ +static u32 smack_next_secid = 10; + +/** + * smk_access - determine if a subject has a specific access to an object + * @subject_label: a pointer to the subject's Smack label + * @object_label: a pointer to the object's Smack label + * @request: the access requested, in "MAY" format + * + * This function looks up the subject/object pair in the + * 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. + */ +int smk_access(char *subject_label, char *object_label, int request) +{ + u32 may = MAY_NOT; + struct smk_list_entry *sp; + struct smack_rule *srp; + + /* + * Hardcoded comparisons. + * + * 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) + return -EACCES; + /* + * 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) + return 0; + /* + * 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) + return 0; + /* + * 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) + return 0; + if (subject_label == smack_known_hat.smk_known || + strcmp(subject_label, smack_known_hat.smk_known) == 0) + return 0; + } + /* + * Beyond here an explicit relationship is required. + * If the requested access is contained in the available + * access (e.g. read is included in readwrite) it's + * good. + */ + for (sp = smack_list; sp != NULL; sp = sp->smk_next) { + srp = &sp->smk_rule; + + 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; + } + } + } + /* + * This is a bit map operation. + */ + if ((request & may) == request) + return 0; + + return -EACCES; +} + +/** + * smk_curacc - determine if current has a specific access to an object + * @object_label: a pointer to the object's Smack label + * @request: the access requested, in "MAY" format + * + * This function checks the current subject label/object label pair + * in the access rule list and returns 0 if the access is permitted, + * non zero otherwise. It allows that current my have the capability + * to override the rules. + */ +int smk_curacc(char *obj_label, u32 mode) +{ + int rc; + + rc = smk_access(current->security, obj_label, mode); + if (rc == 0) + return 0; + + if (capable(CAP_MAC_OVERRIDE)) + return 0; + + return rc; +} + +static DEFINE_MUTEX(smack_known_lock); + +/** + * 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. + * + * Returns a pointer to the entry in the label list that + * matches the passed string, adding it if necessary. + */ +struct smack_known *smk_import_entry(const char *string, int len) +{ + struct smack_known *skp; + char smack[SMK_LABELLEN]; + int found; + int i; + + if (len <= 0 || len > SMK_MAXLEN) + len = SMK_MAXLEN; + + for (i = 0, found = 0; i < SMK_LABELLEN; i++) { + if (found) + smack[i] = '\0'; + else if (i >= len || string[i] > '~' || string[i] <= ' ' || + string[i] == '/') { + smack[i] = '\0'; + found = 1; + } else + smack[i] = string[i]; + } + + if (smack[0] == '\0') + return NULL; + + mutex_lock(&smack_known_lock); + + for (skp = smack_known; skp != NULL; skp = skp->smk_next) + if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) + break; + + if (skp == NULL) { + skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL); + if (skp != NULL) { + skp->smk_next = smack_known; + strncpy(skp->smk_known, smack, SMK_MAXLEN); + skp->smk_secid = smack_next_secid++; + skp->smk_cipso = NULL; + spin_lock_init(&skp->smk_cipsolock); + /* + * Make sure that the entry is actually + * filled before putting it on the list. + */ + smp_mb(); + smack_known = skp; + } + } + + mutex_unlock(&smack_known_lock); + + return skp; +} + +/** + * smk_import - import a smack label + * @string: a text string that might be a Smack label + * @len: the maximum size, or zero if it is NULL terminated. + * + * Returns a pointer to the label in the label list that + * matches the passed string, adding it if necessary. + */ +char *smk_import(const char *string, int len) +{ + struct smack_known *skp; + + skp = smk_import_entry(string, len); + if (skp == NULL) + return NULL; + return skp->smk_known; +} + +/** + * smack_from_secid - find the Smack label associated with a secid + * @secid: an integer that might be associated with a Smack label + * + * Returns a pointer to the appropraite Smack label if there is one, + * otherwise a pointer to the invalid Smack label. + */ +char *smack_from_secid(const u32 secid) +{ + struct smack_known *skp; + + for (skp = smack_known; skp != NULL; skp = skp->smk_next) + if (skp->smk_secid == secid) + return skp->smk_known; + + /* + * If we got this far someone asked for the translation + * of a secid that is not on the list. + */ + return smack_known_invalid.smk_known; +} + +/** + * smack_to_secid - find the secid associated with a Smack label + * @smack: the Smack label + * + * Returns the appropriate secid if there is one, + * otherwise 0 + */ +u32 smack_to_secid(const char *smack) +{ + struct smack_known *skp; + + for (skp = smack_known; skp != NULL; skp = skp->smk_next) + if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) + return skp->smk_secid; + return 0; +} + +/** + * 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. + */ +void smack_from_cipso(u32 level, char *cp, char *result) +{ + struct smack_known *kp; + char *final = NULL; + + for (kp = smack_known; final == NULL && kp != NULL; kp = kp->smk_next) { + if (kp->smk_cipso == NULL) + continue; + + spin_lock_bh(&kp->smk_cipsolock); + + if (kp->smk_cipso->smk_level == level && + memcmp(kp->smk_cipso->smk_catset, cp, SMK_LABELLEN) == 0) + final = kp->smk_known; + + spin_unlock_bh(&kp->smk_cipsolock); + } + if (final == NULL) + final = smack_known_huh.smk_known; + strncpy(result, final, SMK_MAXLEN); + return; +} + +/** + * smack_to_cipso - find the CIPSO option to go with a Smack label + * @smack: a pointer to the smack label in question + * @cp: where to put the result + * + * Returns zero if a value is available, non-zero otherwise. + */ +int smack_to_cipso(const char *smack, struct smack_cipso *cp) +{ + struct smack_known *kp; + + for (kp = smack_known; kp != NULL; kp = kp->smk_next) + if (kp->smk_known == smack || + strcmp(kp->smk_known, smack) == 0) + break; + + if (kp == NULL || kp->smk_cipso == NULL) + return -ENOENT; + + memcpy(cp, kp->smk_cipso, sizeof(struct smack_cipso)); + return 0; +} diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c new file mode 100644 index 000000000000..1c11e4245859 --- /dev/null +++ b/security/smack/smack_lsm.c @@ -0,0 +1,2518 @@ +/* + * Simplified MAC Kernel (smack) security module + * + * This file contains the smack hook function implementations. + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + * + * 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 version 2, + * as published by the Free Software Foundation. + */ + +#include <linux/xattr.h> +#include <linux/pagemap.h> +#include <linux/mount.h> +#include <linux/stat.h> +#include <linux/ext2_fs.h> +#include <linux/kd.h> +#include <asm/ioctls.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/mutex.h> +#include <linux/pipe_fs_i.h> +#include <net/netlabel.h> +#include <net/cipso_ipv4.h> + +#include "smack.h" + +/* + * I hope these are the hokeyist lines of code in the module. Casey. + */ +#define DEVPTS_SUPER_MAGIC 0x1cd1 +#define SOCKFS_MAGIC 0x534F434B +#define TMPFS_MAGIC 0x01021994 + +/** + * smk_fetch - Fetch the smack label from a file. + * @ip: a pointer to the inode + * @dp: a pointer to the dentry + * + * Returns a pointer to the master list entry for the Smack label + * or NULL if there was no label to fetch. + */ +static char *smk_fetch(struct inode *ip, struct dentry *dp) +{ + int rc; + char in[SMK_LABELLEN]; + + if (ip->i_op->getxattr == NULL) + return NULL; + + rc = ip->i_op->getxattr(dp, XATTR_NAME_SMACK, in, SMK_LABELLEN); + if (rc < 0) + return NULL; + + return smk_import(in, rc); +} + +/** + * new_inode_smack - allocate an inode security blob + * @smack: a pointer to the Smack label to use in the blob + * + * Returns the new blob or NULL if there's no memory available + */ +struct inode_smack *new_inode_smack(char *smack) +{ + struct inode_smack *isp; + + isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL); + if (isp == NULL) + return NULL; + + isp->smk_inode = smack; + isp->smk_flags = 0; + mutex_init(&isp->smk_lock); + + return isp; +} + +/* + * LSM hooks. + * We he, that is fun! + */ + +/** + * smack_ptrace - Smack approval on ptrace + * @ptp: parent task pointer + * @ctp: child task pointer + * + * Returns 0 if access is OK, an error code otherwise + * + * Do the capability checks, and require read and write. + */ +static int smack_ptrace(struct task_struct *ptp, struct task_struct *ctp) +{ + int rc; + + rc = cap_ptrace(ptp, ctp); + if (rc != 0) + return rc; + + rc = smk_access(ptp->security, ctp->security, MAY_READWRITE); + if (rc != 0 && __capable(ptp, CAP_MAC_OVERRIDE)) + return 0; + + return rc; +} + +/** + * smack_syslog - Smack approval on syslog + * @type: message type + * + * Require that the task has the floor label + * + * Returns 0 on success, error code otherwise. + */ +static int smack_syslog(int type) +{ + int rc; + char *sp = current->security; + + rc = cap_syslog(type); + if (rc != 0) + return rc; + + if (capable(CAP_MAC_OVERRIDE)) + return 0; + + if (sp != smack_known_floor.smk_known) + rc = -EACCES; + + return rc; +} + + +/* + * Superblock Hooks. + */ + +/** + * smack_sb_alloc_security - allocate a superblock blob + * @sb: the superblock getting the blob + * + * Returns 0 on success or -ENOMEM on error. + */ +static int smack_sb_alloc_security(struct super_block *sb) +{ + struct superblock_smack *sbsp; + + sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); + + if (sbsp == NULL) + return -ENOMEM; + + sbsp->smk_root = smack_known_floor.smk_known; + sbsp->smk_default = smack_known_floor.smk_known; + sbsp->smk_floor = smack_known_floor.smk_known; + sbsp->smk_hat = smack_known_hat.smk_known; + sbsp->smk_initialized = 0; + spin_lock_init(&sbsp->smk_sblock); + + sb->s_security = sbsp; + + return 0; +} + +/** + * smack_sb_free_security - free a superblock blob + * @sb: the superblock getting the blob + * + */ +static void smack_sb_free_security(struct super_block *sb) +{ + kfree(sb->s_security); + sb->s_security = NULL; +} + +/** + * smack_sb_copy_data - copy mount options data for processing + * @type: file system type + * @orig: where to start + * @smackopts + * + * Returns 0 on success or -ENOMEM on error. + * + * Copy the Smack specific mount options out of the mount + * options list. + */ +static int smack_sb_copy_data(struct file_system_type *type, void *orig, + void *smackopts) +{ + char *cp, *commap, *otheropts, *dp; + + /* Binary mount data: just copy */ + if (type->fs_flags & FS_BINARY_MOUNTDATA) { + copy_page(smackopts, orig); + return 0; + } + + otheropts = (char *)get_zeroed_page(GFP_KERNEL); + if (otheropts == NULL) + return -ENOMEM; + + for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { + if (strstr(cp, SMK_FSDEFAULT) == cp) + dp = smackopts; + else if (strstr(cp, SMK_FSFLOOR) == cp) + dp = smackopts; + else if (strstr(cp, SMK_FSHAT) == cp) + dp = smackopts; + else if (strstr(cp, SMK_FSROOT) == cp) + dp = smackopts; + else + dp = otheropts; + + commap = strchr(cp, ','); + if (commap != NULL) + *commap = '\0'; + + if (*dp != '\0') + strcat(dp, ","); + strcat(dp, cp); + } + + strcpy(orig, otheropts); + free_page((unsigned long)otheropts); + + return 0; +} + +/** + * smack_sb_kern_mount - Smack specific mount processing + * @sb: the file system superblock + * @data: the smack mount options + * + * Returns 0 on success, an error code on failure + */ +static int smack_sb_kern_mount(struct super_block *sb, void *data) +{ + struct dentry *root = sb->s_root; + struct inode *inode = root->d_inode; + struct superblock_smack *sp = sb->s_security; + struct inode_smack *isp; + char *op; + char *commap; + char *nsp; + + spin_lock(&sp->smk_sblock); + if (sp->smk_initialized != 0) { + spin_unlock(&sp->smk_sblock); + return 0; + } + sp->smk_initialized = 1; + spin_unlock(&sp->smk_sblock); + + for (op = data; op != NULL; op = commap) { + commap = strchr(op, ','); + if (commap != NULL) + *commap++ = '\0'; + + if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { + op += strlen(SMK_FSHAT); + nsp = smk_import(op, 0); + if (nsp != NULL) + sp->smk_hat = nsp; + } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { + op += strlen(SMK_FSFLOOR); + nsp = smk_import(op, 0); + if (nsp != NULL) + sp->smk_floor = nsp; + } else if (strncmp(op, SMK_FSDEFAULT, + strlen(SMK_FSDEFAULT)) == 0) { + op += strlen(SMK_FSDEFAULT); + nsp = smk_import(op, 0); + if (nsp != NULL) + sp->smk_default = nsp; + } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { + op += strlen(SMK_FSROOT); + nsp = smk_import(op, 0); + if (nsp != NULL) + sp->smk_root = nsp; + } + } + + /* + * Initialize the root inode. + */ + isp = inode->i_security; + if (isp == NULL) + inode->i_security = new_inode_smack(sp->smk_root); + else + isp->smk_inode = sp->smk_root; + + return 0; +} + +/** + * smack_sb_statfs - Smack check on statfs + * @dentry: identifies the file system in question + * + * Returns 0 if current can read the floor of the filesystem, + * and error code otherwise + */ +static int smack_sb_statfs(struct dentry *dentry) +{ + struct superblock_smack *sbp = dentry->d_sb->s_security; + + return smk_curacc(sbp->smk_floor, MAY_READ); +} + +/** + * smack_sb_mount - Smack check for mounting + * @dev_name: unused + * @nd: mount point + * @type: unused + * @flags: unused + * @data: unused + * + * Returns 0 if current can write the floor of the filesystem + * being mounted on, an error code otherwise. + */ +static int smack_sb_mount(char *dev_name, struct nameidata *nd, + char *type, unsigned long flags, void *data) +{ + struct superblock_smack *sbp = nd->mnt->mnt_sb->s_security; + + return smk_curacc(sbp->smk_floor, MAY_WRITE); +} + +/** + * smack_sb_umount - Smack check for unmounting + * @mnt: file system to unmount + * @flags: unused + * + * Returns 0 if current can write the floor of the filesystem + * being unmounted, an error code otherwise. + */ +static int smack_sb_umount(struct vfsmount *mnt, int flags) +{ + struct superblock_smack *sbp; + + sbp = mnt->mnt_sb->s_security; + + return smk_curacc(sbp->smk_floor, MAY_WRITE); +} + +/* + * Inode hooks + */ + +/** + * smack_inode_alloc_security - allocate an inode blob + * @inode - the inode in need of a blob + * + * Returns 0 if it gets a blob, -ENOMEM otherwise + */ +static int smack_inode_alloc_security(struct inode *inode) +{ + inode->i_security = new_inode_smack(current->security); + if (inode->i_security == NULL) + return -ENOMEM; + return 0; +} + +/** + * smack_inode_free_security - free an inode blob + * @inode - the inode with a blob + * + * Clears the blob pointer in inode + */ +static void smack_inode_free_security(struct inode *inode) +{ + kfree(inode->i_security); + inode->i_security = NULL; +} + +/** + * smack_inode_init_security - copy out the smack from an inode + * @inode: the inode + * @dir: unused + * @name: where to put the attribute name + * @value: where to put the attribute value + * @len: where to put the length of the attribute + * + * Returns 0 if it all works out, -ENOMEM if there's no memory + */ +static int smack_inode_init_security(struct inode *inode, struct inode *dir, + char **name, void **value, size_t *len) +{ + char *isp = smk_of_inode(inode); + + if (name) { + *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL); + if (*name == NULL) + return -ENOMEM; + } + + if (value) { + *value = kstrdup(isp, GFP_KERNEL); + if (*value == NULL) + return -ENOMEM; + } + + if (len) + *len = strlen(isp) + 1; + + return 0; +} + +/** + * smack_inode_link - Smack check on link + * @old_dentry: the existing object + * @dir: unused + * @new_dentry: the new object + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *new_dentry) +{ + int rc; + char *isp; + + isp = smk_of_inode(old_dentry->d_inode); + rc = smk_curacc(isp, MAY_WRITE); + + if (rc == 0 && new_dentry->d_inode != NULL) { + isp = smk_of_inode(new_dentry->d_inode); + rc = smk_curacc(isp, MAY_WRITE); + } + + return rc; +} + +/** + * smack_inode_unlink - Smack check on inode deletion + * @dir: containing directory object + * @dentry: file to unlink + * + * Returns 0 if current can write the containing directory + * and the object, error code otherwise + */ +static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) +{ + struct inode *ip = dentry->d_inode; + int rc; + + /* + * You need write access to the thing you're unlinking + */ + rc = smk_curacc(smk_of_inode(ip), MAY_WRITE); + if (rc == 0) + /* + * You also need write access to the containing directory + */ + rc = smk_curacc(smk_of_inode(dir), MAY_WRITE); + + return rc; +} + +/** + * smack_inode_rmdir - Smack check on directory deletion + * @dir: containing directory object + * @dentry: directory to unlink + * + * Returns 0 if current can write the containing directory + * and the directory, error code otherwise + */ +static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) +{ + int rc; + + /* + * You need write access to the thing you're removing + */ + rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); + if (rc == 0) + /* + * You also need write access to the containing directory + */ + rc = smk_curacc(smk_of_inode(dir), MAY_WRITE); + + return rc; +} + +/** + * smack_inode_rename - Smack check on rename + * @old_inode: the old directory + * @old_dentry: unused + * @new_inode: the new directory + * @new_dentry: unused + * + * Read and write access is required on both the old and + * new directories. + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_rename(struct inode *old_inode, + struct dentry *old_dentry, + struct inode *new_inode, + struct dentry *new_dentry) +{ + int rc; + char *isp; + + isp = smk_of_inode(old_dentry->d_inode); + rc = smk_curacc(isp, MAY_READWRITE); + + if (rc == 0 && new_dentry->d_inode != NULL) { + isp = smk_of_inode(new_dentry->d_inode); + rc = smk_curacc(isp, MAY_READWRITE); + } + + return rc; +} + +/** + * smack_inode_permission - Smack version of permission() + * @inode: the inode in question + * @mask: the access requested + * @nd: unused + * + * This is the important Smack hook. + * + * Returns 0 if access is permitted, -EACCES otherwise + */ +static int smack_inode_permission(struct inode *inode, int mask, + struct nameidata *nd) +{ + /* + * No permission to check. Existence test. Yup, it's there. + */ + if (mask == 0) + return 0; + + return smk_curacc(smk_of_inode(inode), mask); +} + +/** + * smack_inode_setattr - Smack check for setting attributes + * @dentry: the object + * @iattr: for the force flag + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) +{ + /* + * Need to allow for clearing the setuid bit. + */ + if (iattr->ia_valid & ATTR_FORCE) + return 0; + + return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); +} + +/** + * smack_inode_getattr - Smack check for getting attributes + * @mnt: unused + * @dentry: the object + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) +{ + return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ); +} + +/** + * smack_inode_setxattr - Smack check for setting xattrs + * @dentry: the object + * @name: name of the attribute + * @value: unused + * @size: unused + * @flags: unused + * + * This protects the Smack attribute explicitly. + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_setxattr(struct dentry *dentry, char *name, + void *value, size_t size, int flags) +{ + if (!capable(CAP_MAC_ADMIN)) { + if (strcmp(name, XATTR_NAME_SMACK) == 0 || + strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || + strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) + return -EPERM; + |