cregit-Linux how code gets into the kernel

Release 4.11 net/netfilter/xt_owner.c

Directory: net/netfilter
/*
 * Kernel module to match various things tied to sockets associated with
 * locally generated outgoing packets.
 *
 * (C) 2000 Marc Boucher <marc@mbsi.ca>
 *
 * Copyright © CC Computer Consultants GmbH, 2007 - 2008
 *
 * 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/module.h>
#include <linux/skbuff.h>
#include <linux/file.h>
#include <linux/cred.h>

#include <net/sock.h>
#include <net/inet_sock.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_owner.h>


static int owner_check(const struct xt_mtchk_param *par) { struct xt_owner_match_info *info = par->matchinfo; struct net *net = par->net; /* Only allow the common case where the userns of the writer * matches the userns of the network namespace. */ if ((info->match & (XT_OWNER_UID|XT_OWNER_GID)) && (current_user_ns() != net->user_ns)) return -EINVAL; /* Ensure the uids are valid */ if (info->match & XT_OWNER_UID) { kuid_t uid_min = make_kuid(net->user_ns, info->uid_min); kuid_t uid_max = make_kuid(net->user_ns, info->uid_max); if (!uid_valid(uid_min) || !uid_valid(uid_max) || (info->uid_max < info->uid_min) || uid_lt(uid_max, uid_min)) { return -EINVAL; } } /* Ensure the gids are valid */ if (info->match & XT_OWNER_GID) { kgid_t gid_min = make_kgid(net->user_ns, info->gid_min); kgid_t gid_max = make_kgid(net->user_ns, info->gid_max); if (!gid_valid(gid_min) || !gid_valid(gid_max) || (info->gid_max < info->gid_min) || gid_lt(gid_max, gid_min)) { return -EINVAL; } } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Eric W. Biedermann213100.00%2100.00%
Total213100.00%2100.00%


static bool owner_mt(const struct sk_buff *skb, struct xt_action_param *par) { const struct xt_owner_match_info *info = par->matchinfo; const struct file *filp; struct sock *sk = skb_to_full_sk(skb); struct net *net = xt_net(par); if (sk == NULL || sk->sk_socket == NULL) return (info->match ^ info->invert) == 0; else if (info->match & info->invert & XT_OWNER_SOCKET) /* * Socket exists but user wanted ! --socket-exists. * (Single ampersands intended.) */ return false; filp = sk->sk_socket->file; if (filp == NULL) return ((info->match ^ info->invert) & (XT_OWNER_UID | XT_OWNER_GID)) == 0; if (info->match & XT_OWNER_UID) { kuid_t uid_min = make_kuid(net->user_ns, info->uid_min); kuid_t uid_max = make_kuid(net->user_ns, info->uid_max); if ((uid_gte(filp->f_cred->fsuid, uid_min) && uid_lte(filp->f_cred->fsuid, uid_max)) ^ !(info->invert & XT_OWNER_UID)) return false; } if (info->match & XT_OWNER_GID) { kgid_t gid_min = make_kgid(net->user_ns, info->gid_min); kgid_t gid_max = make_kgid(net->user_ns, info->gid_max); if ((gid_gte(filp->f_cred->fsgid, gid_min) && gid_lte(filp->f_cred->fsgid, gid_max)) ^ !(info->invert & XT_OWNER_GID)) return false; } return true; }

Contributors

PersonTokensPropCommitsCommitProp
Jan Engelhardt17762.11%444.44%
Eric W. Biedermann8329.12%222.22%
David Howells124.21%111.11%
Eric Dumazet103.51%111.11%
Pablo Neira Ayuso31.05%111.11%
Total285100.00%9100.00%

static struct xt_match owner_mt_reg __read_mostly = { .name = "owner", .revision = 1, .family = NFPROTO_UNSPEC, .checkentry = owner_check, .match = owner_mt, .matchsize = sizeof(struct xt_owner_match_info), .hooks = (1 << NF_INET_LOCAL_OUT) | (1 << NF_INET_POST_ROUTING), .me = THIS_MODULE, };
static int __init owner_mt_init(void) { return xt_register_match(&owner_mt_reg); }

Contributors

PersonTokensPropCommitsCommitProp
Jan Engelhardt16100.00%2100.00%
Total16100.00%2100.00%


static void __exit owner_mt_exit(void) { xt_unregister_match(&owner_mt_reg); }

Contributors

PersonTokensPropCommitsCommitProp
Jan Engelhardt15100.00%2100.00%
Total15100.00%2100.00%

module_init(owner_mt_init); module_exit(owner_mt_exit); MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); MODULE_DESCRIPTION("Xtables: socket owner matching"); MODULE_LICENSE("GPL"); MODULE_ALIAS("ipt_owner"); MODULE_ALIAS("ip6t_owner");

Overall Contributors

PersonTokensPropCommitsCommitProp
Jan Engelhardt31949.00%753.85%
Eric W. Biedermann30146.24%215.38%
Eric Dumazet132.00%17.69%
David Howells121.84%17.69%
Ingo Molnar30.46%17.69%
Pablo Neira Ayuso30.46%17.69%
Total651100.00%13100.00%
Directory: net/netfilter
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