James Morris | 5e6874c | 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 | 5e6874c | 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 | 5e6874c | 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 |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 32 | secmark_tg(struct sk_buff *skb, const struct xt_target_param *par) |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 33 | { |
| 34 | u32 secmark = 0; |
Jan Engelhardt | 7eb3558 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 35 | const struct xt_secmark_target_info *info = par->targinfo; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 36 | |
| 37 | BUG_ON(info->mode != mode); |
| 38 | |
| 39 | switch (mode) { |
| 40 | case SECMARK_MODE_SEL: |
| 41 | secmark = info->u.sel.selsid; |
| 42 | break; |
| 43 | |
| 44 | default: |
| 45 | BUG(); |
| 46 | } |
| 47 | |
Herbert Xu | 3db05fea | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 48 | skb->secmark = secmark; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 49 | return XT_CONTINUE; |
| 50 | } |
| 51 | |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 52 | static bool checkentry_selinux(struct xt_secmark_target_info *info) |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 53 | { |
| 54 | int err; |
| 55 | struct xt_secmark_target_selinux_info *sel = &info->u.sel; |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 56 | |
James Morris | a280b89 | 2006-07-30 20:46:38 -0700 | [diff] [blame] | 57 | sel->selctx[SECMARK_SELCTX_MAX - 1] = '\0'; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 58 | |
| 59 | err = selinux_string_to_sid(sel->selctx, &sel->selsid); |
| 60 | if (err) { |
| 61 | if (err == -EINVAL) |
| 62 | printk(KERN_INFO PFX "invalid SELinux context \'%s\'\n", |
| 63 | sel->selctx); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 64 | return false; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 65 | } |
| 66 | |
| 67 | if (!sel->selsid) { |
| 68 | printk(KERN_INFO PFX "unable to map SELinux context \'%s\'\n", |
| 69 | sel->selctx); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 70 | return false; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 71 | } |
| 72 | |
Paul Moore | d621d35 | 2008-01-29 08:43:36 -0500 | [diff] [blame] | 73 | err = selinux_secmark_relabel_packet_permission(sel->selsid); |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 74 | if (err) { |
| 75 | printk(KERN_INFO PFX "unable to obtain relabeling permission\n"); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 76 | return false; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 77 | } |
| 78 | |
Paul Moore | d621d35 | 2008-01-29 08:43:36 -0500 | [diff] [blame] | 79 | selinux_secmark_refcount_inc(); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 80 | return true; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 81 | } |
| 82 | |
Jan Engelhardt | af5d6dc | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 83 | static bool secmark_tg_check(const struct xt_tgchk_param *par) |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 84 | { |
Jan Engelhardt | af5d6dc | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 85 | struct xt_secmark_target_info *info = par->targinfo; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 86 | |
Jan Engelhardt | af5d6dc | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 87 | if (strcmp(par->table, "mangle") != 0 && |
| 88 | strcmp(par->table, "security") != 0) { |
James Morris | 560ee65 | 2008-06-09 15:57:24 -0700 | [diff] [blame] | 89 | printk(KERN_INFO PFX "target only valid in the \'mangle\' " |
Jan Engelhardt | af5d6dc | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 90 | "or \'security\' tables, not \'%s\'.\n", par->table); |
James Morris | 560ee65 | 2008-06-09 15:57:24 -0700 | [diff] [blame] | 91 | return false; |
| 92 | } |
| 93 | |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 94 | if (mode && mode != info->mode) { |
| 95 | printk(KERN_INFO PFX "mode already set to %hu cannot mix with " |
| 96 | "rules for mode %hu\n", mode, info->mode); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 97 | return false; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 98 | } |
| 99 | |
| 100 | switch (info->mode) { |
| 101 | case SECMARK_MODE_SEL: |
| 102 | if (!checkentry_selinux(info)) |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 103 | return false; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 104 | break; |
| 105 | |
| 106 | default: |
| 107 | printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 108 | return false; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 109 | } |
| 110 | |
| 111 | if (!mode) |
| 112 | mode = info->mode; |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 113 | return true; |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 114 | } |
| 115 | |
Jan Engelhardt | a2df164 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 116 | static void secmark_tg_destroy(const struct xt_tgdtor_param *par) |
Paul Moore | d621d35 | 2008-01-29 08:43:36 -0500 | [diff] [blame] | 117 | { |
| 118 | switch (mode) { |
| 119 | case SECMARK_MODE_SEL: |
| 120 | selinux_secmark_refcount_dec(); |
| 121 | } |
| 122 | } |
| 123 | |
Jan Engelhardt | 55b69e9 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 124 | static struct xt_target secmark_tg_reg __read_mostly = { |
| 125 | .name = "SECMARK", |
| 126 | .revision = 0, |
| 127 | .family = NFPROTO_UNSPEC, |
| 128 | .checkentry = secmark_tg_check, |
| 129 | .destroy = secmark_tg_destroy, |
| 130 | .target = secmark_tg, |
| 131 | .targetsize = sizeof(struct xt_secmark_target_info), |
| 132 | .me = THIS_MODULE, |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 133 | }; |
| 134 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 135 | static int __init secmark_tg_init(void) |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 136 | { |
Jan Engelhardt | 55b69e9 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 137 | return xt_register_target(&secmark_tg_reg); |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 138 | } |
| 139 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 140 | static void __exit secmark_tg_exit(void) |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 141 | { |
Jan Engelhardt | 55b69e9 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 142 | xt_unregister_target(&secmark_tg_reg); |
James Morris | 5e6874c | 2006-06-09 00:30:57 -0700 | [diff] [blame] | 143 | } |
| 144 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 145 | module_init(secmark_tg_init); |
| 146 | module_exit(secmark_tg_exit); |