James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Module for modifying the secmark field of the skb, for use by |
| 3 | * security subsystems. |
| 4 | * |
| 5 | * Based on the nfmark match by: |
| 6 | * (C) 1999-2001 Marc Boucher <marc@mbsi.ca> |
| 7 | * |
James Morris | 560ee65 | 2008-06-09 15:57:24 -0700 | [diff] [blame^] | 8 | * (C) 2006,2008 Red Hat, Inc., James Morris <jmorris@redhat.com> |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License version 2 as |
| 12 | * published by the Free Software Foundation. |
| 13 | * |
| 14 | */ |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/skbuff.h> |
| 17 | #include <linux/selinux.h> |
| 18 | #include <linux/netfilter/x_tables.h> |
| 19 | #include <linux/netfilter/xt_SECMARK.h> |
| 20 | |
| 21 | MODULE_LICENSE("GPL"); |
| 22 | MODULE_AUTHOR("James Morris <jmorris@redhat.com>"); |
Jan Engelhardt | 2ae15b6 | 2008-01-14 23:42:28 -0800 | [diff] [blame] | 23 | MODULE_DESCRIPTION("Xtables: packet security mark modification"); |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 24 | MODULE_ALIAS("ipt_SECMARK"); |
| 25 | MODULE_ALIAS("ip6t_SECMARK"); |
| 26 | |
| 27 | #define PFX "SECMARK: " |
| 28 | |
| 29 | static u8 mode; |
| 30 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 31 | static unsigned int |
| 32 | secmark_tg(struct sk_buff *skb, const struct net_device *in, |
| 33 | const struct net_device *out, unsigned int hooknum, |
| 34 | const struct xt_target *target, const void *targinfo) |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 35 | { |
| 36 | u32 secmark = 0; |
| 37 | const struct xt_secmark_target_info *info = targinfo; |
| 38 | |
| 39 | BUG_ON(info->mode != mode); |
| 40 | |
| 41 | switch (mode) { |
| 42 | case SECMARK_MODE_SEL: |
| 43 | secmark = info->u.sel.selsid; |
| 44 | break; |
| 45 | |
| 46 | default: |
| 47 | BUG(); |
| 48 | } |
| 49 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 50 | skb->secmark = secmark; |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 51 | return XT_CONTINUE; |
| 52 | } |
| 53 | |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 54 | static bool checkentry_selinux(struct xt_secmark_target_info *info) |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 55 | { |
| 56 | int err; |
| 57 | struct xt_secmark_target_selinux_info *sel = &info->u.sel; |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 58 | |
James Morris | a280b89 | 2006-07-30 20:46:38 -0700 | [diff] [blame] | 59 | sel->selctx[SECMARK_SELCTX_MAX - 1] = '\0'; |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 60 | |
| 61 | err = selinux_string_to_sid(sel->selctx, &sel->selsid); |
| 62 | if (err) { |
| 63 | if (err == -EINVAL) |
| 64 | printk(KERN_INFO PFX "invalid SELinux context \'%s\'\n", |
| 65 | sel->selctx); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 66 | return false; |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 67 | } |
| 68 | |
| 69 | if (!sel->selsid) { |
| 70 | printk(KERN_INFO PFX "unable to map SELinux context \'%s\'\n", |
| 71 | sel->selctx); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 72 | return false; |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 73 | } |
| 74 | |
Paul Moore | d621d35 | 2008-01-29 08:43:36 -0500 | [diff] [blame] | 75 | err = selinux_secmark_relabel_packet_permission(sel->selsid); |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 76 | if (err) { |
| 77 | printk(KERN_INFO PFX "unable to obtain relabeling permission\n"); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 78 | return false; |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 79 | } |
| 80 | |
Paul Moore | d621d35 | 2008-01-29 08:43:36 -0500 | [diff] [blame] | 81 | selinux_secmark_refcount_inc(); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 82 | return true; |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 83 | } |
| 84 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 85 | static bool |
| 86 | secmark_tg_check(const char *tablename, const void *entry, |
| 87 | const struct xt_target *target, void *targinfo, |
| 88 | unsigned int hook_mask) |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 89 | { |
| 90 | struct xt_secmark_target_info *info = targinfo; |
| 91 | |
James Morris | 560ee65 | 2008-06-09 15:57:24 -0700 | [diff] [blame^] | 92 | if (strcmp(tablename, "mangle") && strcmp(tablename, "security")) { |
| 93 | printk(KERN_INFO PFX "target only valid in the \'mangle\' " |
| 94 | "or \'security\' tables, not \'%s\'.\n", tablename); |
| 95 | return false; |
| 96 | } |
| 97 | |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 98 | if (mode && mode != info->mode) { |
| 99 | printk(KERN_INFO PFX "mode already set to %hu cannot mix with " |
| 100 | "rules for mode %hu\n", mode, info->mode); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 101 | return false; |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 102 | } |
| 103 | |
| 104 | switch (info->mode) { |
| 105 | case SECMARK_MODE_SEL: |
| 106 | if (!checkentry_selinux(info)) |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 107 | return false; |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 108 | break; |
| 109 | |
| 110 | default: |
| 111 | printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 112 | return false; |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 113 | } |
| 114 | |
| 115 | if (!mode) |
| 116 | mode = info->mode; |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 117 | return true; |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 118 | } |
| 119 | |
Adrian Bunk | f51f5ec | 2008-02-13 17:41:39 -0800 | [diff] [blame] | 120 | static void secmark_tg_destroy(const struct xt_target *target, void *targinfo) |
Paul Moore | d621d35 | 2008-01-29 08:43:36 -0500 | [diff] [blame] | 121 | { |
| 122 | switch (mode) { |
| 123 | case SECMARK_MODE_SEL: |
| 124 | selinux_secmark_refcount_dec(); |
| 125 | } |
| 126 | } |
| 127 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 128 | static struct xt_target secmark_tg_reg[] __read_mostly = { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 129 | { |
| 130 | .name = "SECMARK", |
| 131 | .family = AF_INET, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 132 | .checkentry = secmark_tg_check, |
Paul Moore | d621d35 | 2008-01-29 08:43:36 -0500 | [diff] [blame] | 133 | .destroy = secmark_tg_destroy, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 134 | .target = secmark_tg, |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 135 | .targetsize = sizeof(struct xt_secmark_target_info), |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 136 | .me = THIS_MODULE, |
| 137 | }, |
| 138 | { |
| 139 | .name = "SECMARK", |
| 140 | .family = AF_INET6, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 141 | .checkentry = secmark_tg_check, |
Paul Moore | d621d35 | 2008-01-29 08:43:36 -0500 | [diff] [blame] | 142 | .destroy = secmark_tg_destroy, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 143 | .target = secmark_tg, |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 144 | .targetsize = sizeof(struct xt_secmark_target_info), |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 145 | .me = THIS_MODULE, |
| 146 | }, |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 147 | }; |
| 148 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 149 | static int __init secmark_tg_init(void) |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 150 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 151 | return xt_register_targets(secmark_tg_reg, ARRAY_SIZE(secmark_tg_reg)); |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 152 | } |
| 153 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 154 | static void __exit secmark_tg_exit(void) |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 155 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 156 | xt_unregister_targets(secmark_tg_reg, ARRAY_SIZE(secmark_tg_reg)); |
James Morris | 5e6874cd | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 157 | } |
| 158 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 159 | module_init(secmark_tg_init); |
| 160 | module_exit(secmark_tg_exit); |