diff options
Diffstat (limited to 'security/smack/smackfs.c')
| -rw-r--r-- | security/smack/smackfs.c | 1540 |
1 files changed, 1540 insertions, 0 deletions
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c new file mode 100644 index 00000000..f9346015 --- /dev/null +++ b/security/smack/smackfs.c @@ -0,0 +1,1540 @@ +/* + * 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 */ +}; + +/* + * 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); +LIST_HEAD(smack_rule_list); + +static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT; + +const char *smack_cipso_option = SMACK_CIPSO_OPTION; + + +#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_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); + + list_for_each_entry_rcu(sp, rule_list, list) { + if (sp->smk_subject == srp->smk_subject && + sp->smk_object == srp->smk_object) { + 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_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_rule *rule; + char *data; + int rc = -EINVAL; + + /* + * 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; + } + + rule->smk_subject = smk_import(data, 0); + if (rule->smk_subject == NULL) + goto out_free_rule; + + rule->smk_object = smk_import(data + SMK_LABELLEN, 0); + if (rule->smk_object == NULL) + goto out_free_rule; + + 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_free_rule; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 1]) { + case '-': + break; + case 'w': + case 'W': + rule->smk_access |= MAY_WRITE; + break; + default: + goto out_free_rule; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 2]) { + case '-': + break; + case 'x': + case 'X': + rule->smk_access |= MAY_EXEC; + break; + default: + goto out_free_rule; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 3]) { + case '-': + break; + case 'a': + case 'A': + rule->smk_access |= MAY_APPEND; + break; + default: + goto out_free_rule; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 4]) { + case '-': + break; + case 't': + case 'T': + rule->smk_access |= MAY_TRANSMUTE; + break; + default: + goto out_free_rule; + } + + 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)) + goto out; + +out_free_rule: + kfree(rule); +out: + kfree(data); + return rc; +} + + +/* + * 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; + if (list_empty(&smack_rule_list)) + return NULL; + return smack_rule_list.next; +} + +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; + return NULL; + } + 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); + + 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 void load_seq_stop(struct seq_file *s, void *v) +{ + /* No-op */ +} + +static const 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_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, &smack_rule_list, + &smack_list_lock); +} + +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) +{ + if (*pos == SEQ_READ_FINISHED) + return NULL; + if (list_empty(&smack_known_list)) + return NULL; + + return smack_known_list.next; +} + +static void *cipso_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct list_head *list = v; + + /* + * labels with no associated cipso value wont be printed + * in cipso_seq_show + */ + if (list_is_last(list, &smack_known_list)) { + *pos = SEQ_READ_FINISHED; + return NULL; + } + + return list->next; +} + +/* + * 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 void cipso_seq_stop(struct seq_file *s, void *v) +{ + /* No-op */ +} + +static const 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 + * @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) +{ + if (*pos == SEQ_READ_FINISHED) + return NULL; + if (list_empty(&smk_netlbladdr_list)) + return NULL; + return smk_netlbladdr_list.next; +} + +static void *netlbladdr_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct list_head *list = v; + + if (list_is_last(list, &smk_netlbladdr_list)) { + *pos = SEQ_READ_FINISHED; + return NULL; + } + + return list->next; +} +#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 void netlbladdr_seq_stop(struct seq_file *s, void *v) +{ + /* No-op */ +} + +static const struct seq_operations netlbladdr_seq_ops = { + .start = netlbladdr_seq_start, + .stop = netlbladdr_seq_stop, + .next = netlbladdr_seq_next, + .show = netlbladdr_seq_show, +}; + +/** + * 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(); + + if (*pos == SEQ_READ_FINISHED) + return NULL; + if (list_empty(&tsp->smk_rules)) + return NULL; + return tsp->smk_rules.next; +} + +static void *load_self_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct task_smack *tsp = current_security(); + struct list_head *list = v; + + if (list_is_last(list, &tsp->smk_rules)) { + *pos = SEQ_READ_FINISHED; + return NULL; + } + return list->next; +} + +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 void load_self_seq_stop(struct seq_file *s, void *v) +{ + /* No-op */ +} + +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 = load_self_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_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}, + /* 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); |