diff options
author | Len Brown <len.brown@intel.com> | 2006-01-07 03:50:18 -0500 |
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committer | Len Brown <len.brown@intel.com> | 2006-01-07 03:50:18 -0500 |
commit | ed03f430cdc8c802652467e9097606fedc2c7abc (patch) | |
tree | 30941ec1e6f93e99358fefe18175e5dd800a4379 /security/selinux/xfrm.c | |
parent | ed349a8a0a780ed27e2a765f16cee54d9b63bfee (diff) | |
parent | 6f957eaf79356a32e838f5f262ee9a60544b1d5b (diff) | |
download | op-kernel-dev-ed03f430cdc8c802652467e9097606fedc2c7abc.zip op-kernel-dev-ed03f430cdc8c802652467e9097606fedc2c7abc.tar.gz |
Pull pnpacpi into acpica branch
Diffstat (limited to 'security/selinux/xfrm.c')
-rw-r--r-- | security/selinux/xfrm.c | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c new file mode 100644 index 0000000..5b77765 --- /dev/null +++ b/security/selinux/xfrm.c @@ -0,0 +1,305 @@ +/* + * NSA Security-Enhanced Linux (SELinux) security module + * + * This file contains the SELinux XFRM hook function implementations. + * + * Authors: Serge Hallyn <sergeh@us.ibm.com> + * Trent Jaeger <jaegert@us.ibm.com> + * + * Copyright (C) 2005 International Business Machines Corporation + * + * 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. + */ + +/* + * USAGE: + * NOTES: + * 1. Make sure to enable the following options in your kernel config: + * CONFIG_SECURITY=y + * CONFIG_SECURITY_NETWORK=y + * CONFIG_SECURITY_NETWORK_XFRM=y + * CONFIG_SECURITY_SELINUX=m/y + * ISSUES: + * 1. Caching packets, so they are not dropped during negotiation + * 2. Emulating a reasonable SO_PEERSEC across machines + * 3. Testing addition of sk_policy's with security context via setsockopt + */ +#include <linux/config.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/security.h> +#include <linux/types.h> +#include <linux/netfilter.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_ipv6.h> +#include <linux/ip.h> +#include <linux/tcp.h> +#include <linux/skbuff.h> +#include <linux/xfrm.h> +#include <net/xfrm.h> +#include <net/checksum.h> +#include <net/udp.h> +#include <asm/semaphore.h> + +#include "avc.h" +#include "objsec.h" +#include "xfrm.h" + + +/* + * Returns true if an LSM/SELinux context + */ +static inline int selinux_authorizable_ctx(struct xfrm_sec_ctx *ctx) +{ + return (ctx && + (ctx->ctx_doi == XFRM_SC_DOI_LSM) && + (ctx->ctx_alg == XFRM_SC_ALG_SELINUX)); +} + +/* + * Returns true if the xfrm contains a security blob for SELinux + */ +static inline int selinux_authorizable_xfrm(struct xfrm_state *x) +{ + return selinux_authorizable_ctx(x->security); +} + +/* + * LSM hook implementation that authorizes that a socket can be used + * with the corresponding xfrm_sec_ctx and direction. + */ +int selinux_xfrm_policy_lookup(struct xfrm_policy *xp, u32 sk_sid, u8 dir) +{ + int rc = 0; + u32 sel_sid = SECINITSID_UNLABELED; + struct xfrm_sec_ctx *ctx; + + /* Context sid is either set to label or ANY_ASSOC */ + if ((ctx = xp->security)) { + if (!selinux_authorizable_ctx(ctx)) + return -EINVAL; + + sel_sid = ctx->ctx_sid; + } + + rc = avc_has_perm(sk_sid, sel_sid, SECCLASS_ASSOCIATION, + ((dir == FLOW_DIR_IN) ? ASSOCIATION__RECVFROM : + ((dir == FLOW_DIR_OUT) ? ASSOCIATION__SENDTO : + (ASSOCIATION__SENDTO | ASSOCIATION__RECVFROM))), + NULL); + + return rc; +} + +/* + * Security blob allocation for xfrm_policy and xfrm_state + * CTX does not have a meaningful value on input + */ +static int selinux_xfrm_sec_ctx_alloc(struct xfrm_sec_ctx **ctxp, struct xfrm_user_sec_ctx *uctx) +{ + int rc = 0; + struct task_security_struct *tsec = current->security; + struct xfrm_sec_ctx *ctx; + + BUG_ON(!uctx); + BUG_ON(uctx->ctx_doi != XFRM_SC_ALG_SELINUX); + + if (uctx->ctx_len >= PAGE_SIZE) + return -ENOMEM; + + *ctxp = ctx = kmalloc(sizeof(*ctx) + + uctx->ctx_len, + GFP_KERNEL); + + if (!ctx) + return -ENOMEM; + + ctx->ctx_doi = uctx->ctx_doi; + ctx->ctx_len = uctx->ctx_len; + ctx->ctx_alg = uctx->ctx_alg; + + memcpy(ctx->ctx_str, + uctx+1, + ctx->ctx_len); + rc = security_context_to_sid(ctx->ctx_str, + ctx->ctx_len, + &ctx->ctx_sid); + + if (rc) + goto out; + + /* + * Does the subject have permission to set security or permission to + * do the relabel? + * Must be permitted to relabel from default socket type (process type) + * to specified context + */ + rc = avc_has_perm(tsec->sid, ctx->ctx_sid, + SECCLASS_ASSOCIATION, + ASSOCIATION__SETCONTEXT, NULL); + if (rc) + goto out; + + return rc; + +out: + *ctxp = 0; + kfree(ctx); + return rc; +} + +/* + * LSM hook implementation that allocs and transfers uctx spec to + * xfrm_policy. + */ +int selinux_xfrm_policy_alloc(struct xfrm_policy *xp, struct xfrm_user_sec_ctx *uctx) +{ + int err; + + BUG_ON(!xp); + + err = selinux_xfrm_sec_ctx_alloc(&xp->security, uctx); + return err; +} + + +/* + * LSM hook implementation that copies security data structure from old to + * new for policy cloning. + */ +int selinux_xfrm_policy_clone(struct xfrm_policy *old, struct xfrm_policy *new) +{ + struct xfrm_sec_ctx *old_ctx, *new_ctx; + + old_ctx = old->security; + + if (old_ctx) { + new_ctx = new->security = kmalloc(sizeof(*new_ctx) + + old_ctx->ctx_len, + GFP_KERNEL); + + if (!new_ctx) + return -ENOMEM; + + memcpy(new_ctx, old_ctx, sizeof(*new_ctx)); + memcpy(new_ctx->ctx_str, old_ctx->ctx_str, new_ctx->ctx_len); + } + return 0; +} + +/* + * LSM hook implementation that frees xfrm_policy security information. + */ +void selinux_xfrm_policy_free(struct xfrm_policy *xp) +{ + struct xfrm_sec_ctx *ctx = xp->security; + if (ctx) + kfree(ctx); +} + +/* + * LSM hook implementation that allocs and transfers sec_ctx spec to + * xfrm_state. + */ +int selinux_xfrm_state_alloc(struct xfrm_state *x, struct xfrm_user_sec_ctx *uctx) +{ + int err; + + BUG_ON(!x); + + err = selinux_xfrm_sec_ctx_alloc(&x->security, uctx); + return err; +} + +/* + * LSM hook implementation that frees xfrm_state security information. + */ +void selinux_xfrm_state_free(struct xfrm_state *x) +{ + struct xfrm_sec_ctx *ctx = x->security; + if (ctx) + kfree(ctx); +} + +/* + * LSM hook that controls access to unlabelled packets. If + * a xfrm_state is authorizable (defined by macro) then it was + * already authorized by the IPSec process. If not, then + * we need to check for unlabelled access since this may not have + * gone thru the IPSec process. + */ +int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb) +{ + int i, rc = 0; + struct sec_path *sp; + + sp = skb->sp; + + if (sp) { + /* + * __xfrm_policy_check does not approve unless xfrm_policy_ok + * says that spi's match for policy and the socket. + * + * Only need to verify the existence of an authorizable sp. + */ + for (i = 0; i < sp->len; i++) { + struct xfrm_state *x = sp->x[i].xvec; + + if (x && selinux_authorizable_xfrm(x)) + goto accept; + } + } + + /* check SELinux sock for unlabelled access */ + rc = avc_has_perm(isec_sid, SECINITSID_UNLABELED, SECCLASS_ASSOCIATION, + ASSOCIATION__RECVFROM, NULL); + if (rc) + goto drop; + +accept: + return 0; + +drop: + return rc; +} + +/* + * POSTROUTE_LAST hook's XFRM processing: + * If we have no security association, then we need to determine + * whether the socket is allowed to send to an unlabelled destination. + * If we do have a authorizable security association, then it has already been + * checked in xfrm_policy_lookup hook. + */ +int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb) +{ + struct dst_entry *dst; + int rc = 0; + + dst = skb->dst; + + if (dst) { + struct dst_entry *dst_test; + + for (dst_test = dst; dst_test != 0; + dst_test = dst_test->child) { + struct xfrm_state *x = dst_test->xfrm; + + if (x && selinux_authorizable_xfrm(x)) + goto accept; + } + } + + rc = avc_has_perm(isec_sid, SECINITSID_UNLABELED, SECCLASS_ASSOCIATION, + ASSOCIATION__SENDTO, NULL); + if (rc) + goto drop; + +accept: + return NF_ACCEPT; + +drop: + return NF_DROP; +} |