// SPDX-License-Identifier: GPL-2.0 /** * net/tipc/crypto.c: TIPC crypto for key handling & packet en/decryption * * Copyright (c) 2019, Ericsson AB * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the names of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #include #include "crypto.h" #include "msg.h" #include "bcast.h" #define TIPC_TX_GRACE_PERIOD msecs_to_jiffies(5000) /* 5s */ #define TIPC_TX_LASTING_TIME msecs_to_jiffies(10000) /* 10s */ #define TIPC_RX_ACTIVE_LIM msecs_to_jiffies(3000) /* 3s */ #define TIPC_RX_PASSIVE_LIM msecs_to_jiffies(15000) /* 15s */ #define TIPC_MAX_TFMS_DEF 10 #define TIPC_MAX_TFMS_LIM 1000 /** * TIPC Key ids */ enum { KEY_MASTER = 0, KEY_MIN = KEY_MASTER, KEY_1 = 1, KEY_2, KEY_3, KEY_MAX = KEY_3, }; /** * TIPC Crypto statistics */ enum { STAT_OK, STAT_NOK, STAT_ASYNC, STAT_ASYNC_OK, STAT_ASYNC_NOK, STAT_BADKEYS, /* tx only */ STAT_BADMSGS = STAT_BADKEYS, /* rx only */ STAT_NOKEYS, STAT_SWITCHES, MAX_STATS, }; /* TIPC crypto statistics' header */ static const char *hstats[MAX_STATS] = {"ok", "nok", "async", "async_ok", "async_nok", "badmsgs", "nokeys", "switches"}; /* Max TFMs number per key */ int sysctl_tipc_max_tfms __read_mostly = TIPC_MAX_TFMS_DEF; /* Key exchange switch, default: on */ int sysctl_tipc_key_exchange_enabled __read_mostly = 1; /** * struct tipc_key - TIPC keys' status indicator * * 7 6 5 4 3 2 1 0 * +-----+-----+-----+-----+-----+-----+-----+-----+ * key: | (reserved)|passive idx| active idx|pending idx| * +-----+-----+-----+-----+-----+-----+-----+-----+ */ struct tipc_key { #define KEY_BITS (2) #define KEY_MASK ((1 << KEY_BITS) - 1) union { struct { #if defined(__LITTLE_ENDIAN_BITFIELD) u8 pending:2, active:2, passive:2, /* rx only */ reserved:2; #elif defined(__BIG_ENDIAN_BITFIELD) u8 reserved:2, passive:2, /* rx only */ active:2, pending:2; #else #error "Please fix " #endif } __packed; u8 keys; }; }; /** * struct tipc_tfm - TIPC TFM structure to form a list of TFMs */ struct tipc_tfm { struct crypto_aead *tfm; struct list_head list; }; /** * struct tipc_aead - TIPC AEAD key structure * @tfm_entry: per-cpu pointer to one entry in TFM list * @crypto: TIPC crypto owns this key * @cloned: reference to the source key in case cloning * @users: the number of the key users (TX/RX) * @salt: the key's SALT value * @authsize: authentication tag size (max = 16) * @mode: crypto mode is applied to the key * @hint[]: a hint for user key * @rcu: struct rcu_head * @key: the aead key * @gen: the key's generation * @seqno: the key seqno (cluster scope) * @refcnt: the key reference counter */ struct tipc_aead { #define TIPC_AEAD_HINT_LEN (5) struct tipc_tfm * __percpu *tfm_entry; struct tipc_crypto *crypto; struct tipc_aead *cloned; atomic_t users; u32 salt; u8 authsize; u8 mode; char hint[2 * TIPC_AEAD_HINT_LEN + 1]; struct rcu_head rcu; struct tipc_aead_key *key; u16 gen; atomic64_t seqno ____cacheline_aligned; refcount_t refcnt ____cacheline_aligned; } ____cacheline_aligned; /** * struct tipc_crypto_stats - TIPC Crypto statistics */ struct tipc_crypto_stats { unsigned int stat[MAX_STATS]; }; /** * struct tipc_crypto - TIPC TX/RX crypto structure * @net: struct net * @node: TIPC node (RX) * @aead: array of pointers to AEAD keys for encryption/decryption * @peer_rx_active: replicated peer RX active key index * @key_gen: TX/RX key generation * @key: the key states * @skey_mode: session key's mode * @skey: received session key * @wq: common workqueue on TX crypto * @work: delayed work sched for TX/RX * @key_distr: key distributing state * @stats: the crypto statistics * @name: the crypto name * @sndnxt: the per-peer sndnxt (TX) * @timer1: general timer 1 (jiffies) * @timer2: general timer 2 (jiffies) * @working: the crypto is working or not * @key_master: flag indicates if master key exists * @legacy_user: flag indicates if a peer joins w/o master key (for bwd comp.) * @nokey: no key indication * @lock: tipc_key lock */ struct tipc_crypto { struct net *net; struct tipc_node *node; struct tipc_aead __rcu *aead[KEY_MAX + 1]; atomic_t peer_rx_active; u16 key_gen; struct tipc_key key; u8 skey_mode; struct tipc_aead_key *skey; struct workqueue_struct *wq; struct delayed_work work; #define KEY_DISTR_SCHED 1 #define KEY_DISTR_COMPL 2 atomic_t key_distr; struct tipc_crypto_stats __percpu *stats; char name[48]; atomic64_t sndnxt ____cacheline_aligned; unsigned long timer1; unsigned long timer2; union { struct { u8 working:1; u8 key_master:1; u8 legacy_user:1; u8 nokey: 1; }; u8 flags; }; spinlock_t lock; /* crypto lock */ } ____cacheline_aligned; /* struct tipc_crypto_tx_ctx - TX context for callbacks */ struct tipc_crypto_tx_ctx { struct tipc_aead *aead; struct tipc_bearer *bearer; struct tipc_media_addr dst; }; /* struct tipc_crypto_rx_ctx - RX context for callbacks */ struct tipc_crypto_rx_ctx { struct tipc_aead *aead; struct tipc_bearer *bearer; }; static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead); static inline void tipc_aead_put(struct tipc_aead *aead); static void tipc_aead_free(struct rcu_head *rp); static int tipc_aead_users(struct tipc_aead __rcu *aead); static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim); static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim); static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val); static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead); static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey, u8 mode); static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src); static void *tipc_aead_mem_alloc(struct crypto_aead *tfm, unsigned int crypto_ctx_size, u8 **iv, struct aead_request **req, struct scatterlist **sg, int nsg); static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb, struct tipc_bearer *b, struct tipc_media_addr *dst, struct tipc_node *__dnode); static void tipc_aead_encrypt_done(struct crypto_async_request *base, int err); static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead, struct sk_buff *skb, struct tipc_bearer *b); static void tipc_aead_decrypt_done(struct crypto_async_request *base, int err); static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr); static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead, u8 tx_key, struct sk_buff *skb, struct tipc_crypto *__rx); static inline void tipc_crypto_key_set_state(struct tipc_crypto *c, u8 new_passive, u8 new_active, u8 new_pending); static int tipc_crypto_key_attach(struct tipc_crypto *c, struct tipc_aead *aead, u8 pos, bool master_key); static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending); static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx, struct tipc_crypto *rx, struct sk_buff *skb, u8 tx_key); static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb); static int tipc_crypto_key_revoke(struct net *net, u8 tx_key); static inline void tipc_crypto_clone_msg(struct net *net, struct sk_buff *_skb, struct tipc_bearer *b, struct tipc_media_addr *dst, struct tipc_node *__dnode, u8 type); static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead, struct tipc_bearer *b, struct sk_buff **skb, int err); static void tipc_crypto_do_cmd(struct net *net, int cmd); static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf); static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new, char *buf); static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey, u16 gen, u8 mode, u32 dnode); static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr); static void tipc_crypto_work_rx(struct work_struct *work); #define is_tx(crypto) (!(crypto)->node) #define is_rx(crypto) (!is_tx(crypto)) #define key_next(cur) ((cur) % KEY_MAX + 1) #define tipc_aead_rcu_ptr(rcu_ptr, lock) \ rcu_dereference_protected((rcu_ptr), lockdep_is_held(lock)) #define tipc_aead_rcu_replace(rcu_ptr, ptr, lock) \ do { \ typeof(rcu_ptr) __tmp = rcu_dereference_protected((rcu_ptr), \ lockdep_is_held(lock)); \ rcu_assign_pointer((rcu_ptr), (ptr)); \ tipc_aead_put(__tmp); \ } while (0) #define tipc_crypto_key_detach(rcu_ptr, lock) \ tipc_aead_rcu_replace((rcu_ptr), NULL, lock) /** * tipc_aead_key_validate - Validate a AEAD user key */ int tipc_aead_key_validate(struct tipc_aead_key *ukey, struct genl_info *info) { int keylen; /* Check if algorithm exists */ if (unlikely(!crypto_has_alg(ukey->alg_name, 0, 0))) { GENL_SET_ERR_MSG(info, "unable to load the algorithm (module existed?)"); return -ENODEV; } /* Currently, we only support the "gcm(aes)" cipher algorithm */ if (strcmp(ukey->alg_name, "gcm(aes)")) { GENL_SET_ERR_MSG(info, "not supported yet the algorithm"); return -ENOTSUPP; } /* Check if key size is correct */ keylen = ukey->keylen - TIPC_AES_GCM_SALT_SIZE; if (unlikely(keylen != TIPC_AES_GCM_KEY_SIZE_128 && keylen != TIPC_AES_GCM_KEY_SIZE_192 && keylen != TIPC_AES_GCM_KEY_SIZE_256)) { GENL_SET_ERR_MSG(info, "incorrect key length (20, 28 or 36 octets?)"); return -EKEYREJECTED; } return 0; } static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead) { struct tipc_aead *tmp; rcu_read_lock(); tmp = rcu_dereference(aead); if (unlikely(!tmp || !refcount_inc_not_zero(&tmp->refcnt))) tmp = NULL; rcu_read_unlock(); return tmp; } static inline void tipc_aead_put(struct tipc_aead *aead) { if (aead && refcount_dec_and_test(&aead->refcnt)) call_rcu(&aead->rcu, tipc_aead_free); } /** * tipc_aead_free - Release AEAD key incl. all the TFMs in the list * @rp: rcu head pointer */ static void tipc_aead_free(struct rcu_head *rp) { struct tipc_aead *aead = container_of(rp, struct tipc_aead, rcu); struct tipc_tfm *tfm_entry, *head, *tmp; if (aead->cloned) { tipc_aead_put(aead->cloned); } else { head = *get_cpu_ptr(aead->tfm_entry); put_cpu_ptr(aead->tfm_entry); list_for_each_entry_safe(tfm_entry, tmp, &head->list, list) { crypto_free_aead(tfm_entry->tfm); list_del(&tfm_entry->list); kfree(tfm_entry); } /* Free the head */ crypto_free_aead(head->tfm); list_del(&head->list); kfree(head); } free_percpu(aead->tfm_entry); kzfree(aead->key); kfree(aead); } static int tipc_aead_users(struct tipc_aead __rcu *aead) { struct tipc_aead *tmp; int users = 0; rcu_read_lock(); tmp = rcu_dereference(aead); if (tmp) users = atomic_read(&tmp->users); rcu_read_unlock(); return users; } static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim) { struct tipc_aead *tmp; rcu_read_lock(); tmp = rcu_dereference(aead); if (tmp) atomic_add_unless(&tmp->users, 1, lim); rcu_read_unlock(); } static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim) { struct tipc_aead *tmp; rcu_read_lock(); tmp = rcu_dereference(aead); if (tmp) atomic_add_unless(&rcu_dereference(aead)->users, -1, lim); rcu_read_unlock(); } static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val) { struct tipc_aead *tmp; int cur; rcu_read_lock(); tmp = rcu_dereference(aead); if (tmp) { do { cur = atomic_read(&tmp->users); if (cur == val) break; } while (atomic_cmpxchg(&tmp->users, cur, val) != cur); } rcu_read_unlock(); } /** * tipc_aead_tfm_next - Move TFM entry to the next one in list and return it */ static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead) { struct tipc_tfm **tfm_entry; struct crypto_aead *tfm; tfm_entry = get_cpu_ptr(aead->tfm_entry); *tfm_entry = list_next_entry(*tfm_entry, list); tfm = (*tfm_entry)->tfm; put_cpu_ptr(tfm_entry); return tfm; } /** * tipc_aead_init - Initiate TIPC AEAD * @aead: returned new TIPC AEAD key handle pointer * @ukey: pointer to user key data * @mode: the key mode * * Allocate a (list of) new cipher transformation (TFM) with the specific user * key data if valid. The number of the allocated TFMs can be set via the sysfs * "net/tipc/max_tfms" first. * Also, all the other AEAD data are also initialized. * * Return: 0 if the initiation is successful, otherwise: < 0 */ static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey, u8 mode) { struct tipc_tfm *tfm_entry, *head; struct crypto_aead *tfm; struct tipc_aead *tmp; int keylen, err, cpu; int tfm_cnt = 0; if (unlikely(*aead)) return -EEXIST; /* Allocate a new AEAD */ tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC); if (unlikely(!tmp)) return -ENOMEM; /* The key consists of two parts: [AES-KEY][SALT] */ keylen = ukey->keylen - TIPC_AES_GCM_SALT_SIZE; /* Allocate per-cpu TFM entry pointer */ tmp->tfm_entry = alloc_percpu(struct tipc_tfm *); if (!tmp->tfm_entry) { kfree_sensitive(tmp); return -ENOMEM; } /* Make a list of TFMs with the user key data */ do { tfm = crypto_alloc_aead(ukey->alg_name, 0, 0); if (IS_ERR(tfm)) { err = PTR_ERR(tfm); break; } if (unlikely(!tfm_cnt && crypto_aead_ivsize(tfm) != TIPC_AES_GCM_IV_SIZE)) { crypto_free_aead(tfm); err = -ENOTSUPP; break; } err = crypto_aead_setauthsize(tfm, TIPC_AES_GCM_TAG_SIZE); err |= crypto_aead_setkey(tfm, ukey->key, keylen); if (unlikely(err)) { crypto_free_aead(tfm); break; } tfm_entry = kmalloc(sizeof(*tfm_entry), GFP_KERNEL); if (unlikely(!tfm_entry)) { crypto_free_aead(tfm); err = -ENOMEM; break; } INIT_LIST_HEAD(&tfm_entry->list); tfm_entry->tfm = tfm; /* First entry? */ if (!tfm_cnt) { head = tfm_entry; for_each_possible_cpu(cpu) { *per_cpu_ptr(tmp->tfm_entry, cpu) = head; } } else { list_add_tail(&tfm_entry->list, &head->list); } } while (++tfm_cnt < sysctl_tipc_max_tfms); /* Not any TFM is allocated? */ if (!tfm_cnt) { free_percpu(tmp->tfm_entry); kfree_sensitive(tmp); return err; } /* Form a hex string of some last bytes as the key's hint */ bin2hex(tmp->hint, ukey->key + keylen - TIPC_AEAD_HINT_LEN, TIPC_AEAD_HINT_LEN); /* Initialize the other data */ tmp->mode = mode; tmp->cloned = NULL; tmp->authsize = TIPC_AES_GCM_TAG_SIZE; tmp->key = kmemdup(ukey, tipc_aead_key_size(ukey), GFP_KERNEL); memcpy(&tmp->salt, ukey->key + keylen, TIPC_AES_GCM_SALT_SIZE); atomic_set(&tmp->users, 0); atomic64_set(&tmp->seqno, 0); refcount_set(&tmp->refcnt, 1); *aead = tmp; return 0; } /** * tipc_aead_clone - Clone a TIPC AEAD key * @dst: dest key for the cloning * @src: source key to clone from * * Make a "copy" of the source AEAD key data to the dest, the TFMs list is * common for the keys. * A reference to the source is hold in the "cloned" pointer for the later * freeing purposes. * * Note: this must be done in cluster-key mode only! * Return: 0 in case of success, otherwise < 0 */ static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src) { struct tipc_aead *aead; int cpu; if (!src) return -ENOKEY; if (src->mode != CLUSTER_KEY) return -EINVAL; if (unlikely(*dst)) return -EEXIST; aead = kzalloc(sizeof(*aead), GFP_ATOMIC); if (unlikely(!aead)) return -ENOMEM; aead->tfm_entry = alloc_percpu_gfp(struct tipc_tfm *, GFP_ATOMIC); if (unlikely(!aead->tfm_entry)) { kfree_sensitive(aead); return -ENOMEM; } for_each_possible_cpu(cpu) { *per_cpu_ptr(aead->tfm_entry, cpu) = *per_cpu_ptr(src->tfm_entry, cpu); } memcpy(aead->hint, src->hint, sizeof(src->hint)); aead->mode = src->mode; aead->salt = src->salt; aead->authsize = src->authsize; atomic_set(&aead->users, 0); atomic64_set(&aead->seqno, 0); refcount_set(&aead->refcnt, 1); WARN_ON(!refcount_inc_not_zero(&src->refcnt)); aead->cloned = src; *dst = aead; return 0; } /** * tipc_aead_mem_alloc - Allocate memory for AEAD request operations * @tfm: cipher handle to be registered with the request * @crypto_ctx_size: size of crypto context for callback * @iv: returned pointer to IV data * @req: returned pointer to AEAD request data * @sg: returned pointer to SG lists * @nsg: number of SG lists to be allocated * * Allocate memory to store the crypto context data, AEAD request, IV and SG * lists, the memory layout is as follows: * crypto_ctx || iv || aead_req || sg[] * * Return: the pointer to the memory areas in case of success, otherwise NULL */ static void *tipc_aead_mem_alloc(struct crypto_aead *tfm, unsigned int crypto_ctx_size, u8 **iv, struct aead_request **req, struct scatterlist **sg, int nsg) { unsigned int iv_size, req_size; unsigned int len; u8 *mem; iv_size = crypto_aead_ivsize(tfm); req_size = sizeof(**req) + crypto_aead_reqsize(tfm); len = crypto_ctx_size; len += iv_size; len += crypto_aead_alignmask(tfm) & ~(crypto_tfm_ctx_alignment() - 1); len = ALIGN(len, crypto_tfm_ctx_alignment()); len += req_size; len = ALIGN(len, __alignof__(struct scatterlist)); len += nsg * sizeof(**sg); mem = kmalloc(len, GFP_ATOMIC); if (!mem) return NULL; *iv = (u8 *)PTR_ALIGN(mem + crypto_ctx_size, crypto_aead_alignmask(tfm) + 1); *req = (struct aead_request *)PTR_ALIGN(*iv + iv_size, crypto_tfm_ctx_alignment()); *sg = (struct scatterlist *)PTR_ALIGN((u8 *)*req + req_size, __alignof__(struct scatterlist)); return (void *)mem; } /** * tipc_aead_encrypt - Encrypt a message * @aead: TIPC AEAD key for the message encryption * @skb: the input/output skb * @b: TIPC bearer where the message will be delivered after the encryption * @dst: the destination media address * @__dnode: TIPC dest node if "known" * * Return: * 0 : if the encryption has completed * -EINPROGRESS/-EBUSY : if a callback will be performed * < 0 : the encryption has failed */ static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb, struct tipc_bearer *b, struct tipc_media_addr *dst, struct tipc_node *__dnode) { struct crypto_aead *tfm = tipc_aead_tfm_next(aead); struct tipc_crypto_tx_ctx *tx_ctx; struct aead_request *req; struct sk_buff *trailer; struct scatterlist *sg; struct tipc_ehdr *ehdr; int ehsz, len, tailen, nsg, rc; void *ctx; u32 salt; u8 *iv; /* Make sure message len at least 4-byte aligned */ len = ALIGN(skb->len, 4); tailen = len - skb->len + aead->authsize; /* Expand skb tail for authentication tag: * As for simplicity, we'd have made sure skb having enough tailroom * for authentication tag @skb allocation. Even when skb is nonlinear * but there is no frag_list, it should be still fine! * Otherwise, we must cow it to be a writable buffer with the tailroom. */ SKB_LINEAR_ASSERT(skb); if (tailen > skb_tailroom(skb)) { pr_debug("TX(): skb tailroom is not enough: %d, requires: %d\n", skb_tailroom(skb), tailen); } if (unlikely(!skb_cloned(skb) && tailen <= skb_tailroom(skb))) { nsg = 1; trailer = skb; } else { /* TODO: We could avoid skb_cow_data() if skb has no frag_list * e.g. by skb_fill_page_desc() to add another page to the skb * with the wanted tailen... However, page skbs look not often, * so take it easy now! * Cloned skbs e.g. from link_xmit() seems no choice though :( */ nsg = skb_cow_data(skb, tailen, &trailer); if (unlikely(nsg < 0)) { pr_err("TX: skb_cow_data() returned %d\n", nsg); return nsg; } } pskb_put(skb, trailer, tailen); /* Allocate memory for the AEAD operation */ ctx = tipc_aead_mem_alloc(tfm, sizeof(*tx_ctx), &iv, &req, &sg, nsg); if (unlikely(!ctx)) return -ENOMEM; TIPC_SKB_CB(skb)->crypto_ctx = ctx; /* Map skb to the sg lists */ sg_init_table(sg, nsg); rc = skb_to_sgvec(skb, sg, 0, skb->len); if (unlikely(rc < 0)) { pr_err("TX: skb_to_sgvec() returned %d, nsg %d!\n", rc, nsg); goto exit; } /* Prepare IV: [SALT (4 octets)][SEQNO (8 octets)] * In case we're in cluster-key mode, SALT is varied by xor-ing with * the source address (or w0 of id), otherwise with the dest address * if dest is known. */ ehdr = (struct tipc_ehdr *)skb->data; salt = aead->salt; if (aead->mode == CLUSTER_KEY) salt ^= ehdr->addr; /* __be32 */ else if (__dnode) salt ^= tipc_node_get_addr(__dnode); memcpy(iv, &salt, 4); memcpy(iv + 4, (u8 *)&ehdr->seqno, 8); /* Prepare request */ ehsz = tipc_ehdr_size(ehdr); aead_request_set_tfm(req, tfm); aead_request_set_ad(req, ehsz); aead_request_set_crypt(req, sg, sg, len - ehsz, iv); /* Set callback function & data */ aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, tipc_aead_encrypt_done, skb); tx_ctx = (struct tipc_crypto_tx_ctx *)ctx; tx_ctx->aead = aead; tx_ctx->bearer = b; memcpy(&tx_ctx->dst, dst, sizeof(*dst)); /* Hold bearer */ if (unlikely(!tipc_bearer_hold(b))) { rc = -ENODEV; goto exit; } /* Now, do encrypt */ rc = crypto_aead_encrypt(req); if (rc == -EINPROGRESS || rc == -EBUSY) return rc; tipc_bearer_put(b); exit: kfree(ctx); TIPC_SKB_CB(skb)->crypto_ctx = NULL; return rc; } static void tipc_aead_encrypt_done(struct crypto_async_request *base, int err) { struct sk_buff *skb = base->data; struct tipc_crypto_tx_ctx *tx_ctx = TIPC_SKB_CB(skb)->crypto_ctx; struct tipc_bearer *b = tx_ctx->bearer; struct tipc_aead *aead = tx_ctx->aead; struct tipc_crypto *tx = aead->crypto; struct net *net = tx->net; switch (err) { case 0: this_cpu_inc(tx->stats->stat[STAT_ASYNC_OK]); rcu_read_lock(); if (likely(test_bit(0, &b->up))) b->media->send_msg(net, skb, b, &tx_ctx->dst); else kfree_skb(skb); rcu_read_unlock(); break; case -EINPROGRESS: return; default: this_cpu_inc(tx->stats->stat[STAT_ASYNC_NOK]); kfree_skb(skb); break; } kfree(tx_ctx); tipc_bearer_put(b); tipc_aead_put(aead); } /** * tipc_aead_decrypt - Decrypt an encrypted message * @net: struct net * @aead: TIPC AEAD for the message decryption * @skb: the input/output skb * @b: TIPC bearer where the message has been received * * Return: * 0 : if the decryption has completed * -EINPROGRESS/-EBUSY : if a callback will be performed * < 0 : the decryption has failed */ static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead, struct sk_buff *skb, struct tipc_bearer *b) { struct tipc_crypto_rx_ctx *rx_ctx; struct aead_request *req; struct crypto_aead *tfm; struct sk_buff *unused; struct scatterlist *sg; struct tipc_ehdr *ehdr; int ehsz, nsg, rc; void *ctx; u32 salt; u8 *iv; if (unlikely(!aead)) return -ENOKEY; /* Cow skb data if needed */ if (likely(!skb_cloned(skb) && (!skb_is_nonlinear(skb) || !skb_has_frag_list(skb)))) { nsg = 1 + skb_shinfo(skb)->nr_frags; } else { nsg = skb_cow_data(skb, 0, &unused); if (unlikely(nsg < 0)) { pr_err("RX: skb_cow_data() returned %d\n", nsg); return nsg; } } /* Allocate memory for the AEAD operation */ tfm = tipc_aead_tfm_next(aead); ctx = tipc_aead_mem_alloc(tfm, sizeof(*rx_ctx), &iv, &req, &sg, nsg); if (unlikely(!ctx)) return -ENOMEM; TIPC_SKB_CB(skb)->crypto_ctx = ctx; /* Map skb to the sg lists */ sg_init_table(sg, nsg); rc = skb_to_sgvec(skb, sg, 0, skb->len); if (unlikely(rc < 0)) { pr_err("RX: skb_to_sgvec() returned %d, nsg %d\n", rc, nsg); goto exit; } /* Reconstruct IV: */ ehdr = (struct tipc_ehdr *)skb->data; salt = aead->salt; if (aead->mode == CLUSTER_KEY) salt ^= ehdr->addr; /* __be32 */ else if (ehdr->destined) salt ^= tipc_own_addr(net); memcpy(iv, &salt, 4); memcpy(iv + 4, (u8 *)&ehdr->seqno, 8); /* Prepare request */ ehsz = tipc_ehdr_size(ehdr); aead_request_set_tfm(req, tfm); aead_request_set_ad(req, ehsz); aead_request_set_crypt(req, sg, sg, skb->len - ehsz, iv); /* Set callback function & data */ aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, tipc_aead_decrypt_done, skb); rx_ctx = (struct tipc_crypto_rx_ctx *)ctx; rx_ctx->aead = aead; rx_ctx->bearer = b; /* Hold bearer */ if (unlikely(!tipc_bearer_hold(b))) { rc = -ENODEV; goto exit; } /* Now, do decrypt */ rc = crypto_aead_decrypt(req); if (rc == -EINPROGRESS || rc == -EBUSY) return rc; tipc_bearer_put(b); exit: kfree(ctx); TIPC_SKB_CB(skb)->crypto_ctx = NULL; return rc; } static void tipc_aead_decrypt_done(struct crypto_async_request *base, int err) { struct sk_buff *skb = base->data; struct tipc_crypto_rx_ctx *rx_ctx = TIPC_SKB_CB(skb)->crypto_ctx; struct tipc_bearer *b = rx_ctx->bearer; struct tipc_aead *aead = rx_ctx->aead; struct tipc_crypto_stats __percpu *stats = aead->crypto->stats; struct net *net = aead->crypto->net; switch (err) { case 0: this_cpu_inc(stats->stat[STAT_ASYNC_OK]); break; case -EINPROGRESS: return; default: this_cpu_inc(stats->stat[STAT_ASYNC_NOK]); break; } kfree(rx_ctx); tipc_crypto_rcv_complete(net, aead, b, &skb, err); if (likely(skb)) { if (likely(test_bit(0, &b->up))) tipc_rcv(net, skb, b); else kfree_skb(skb); } tipc_bearer_put(b); } static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr) { return (ehdr->user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE; } /** * tipc_ehdr_validate - Validate an encryption message * @skb: the message buffer * * Returns "true" if this is a valid encryption message, otherwise "false" */ bool tipc_ehdr_validate(struct sk_buff *skb) { struct tipc_ehdr *ehdr; int ehsz; if (unlikely(!pskb_may_pull(skb, EHDR_MIN_SIZE))) return false; ehdr = (struct tipc_ehdr *)skb->data; if (unlikely(ehdr->version != TIPC_EVERSION)) return false; ehsz = tipc_ehdr_size(ehdr); if (unlikely(!pskb_may_pull(skb, ehsz))) return false; if (unlikely(skb->len <= ehsz + TIPC_AES_GCM_TAG_SIZE)) return false; return true; } /** * tipc_ehdr_build - Build TIPC encryption message header * @net: struct net * @aead: TX AEAD key to be used for the message encryption * @tx_key: key id used for the message encryption * @skb: input/output message skb * @__rx: RX crypto handle if dest is "known" * * Return: the header size if the building is successful, otherwise < 0 */ static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead, u8 tx_key, struct sk_buff *skb, struct tipc_crypto *__rx) { struct tipc_msg *hdr = buf_msg(skb); struct tipc_ehdr *ehdr; u32 user = msg_user(hdr); u64 seqno; int ehsz; /* Make room for encryption header */ ehsz = (user != LINK_CONFIG) ? EHDR_SIZE : EHDR_CFG_SIZE; WARN_ON(skb_headroom(skb) < ehsz); ehdr = (struct tipc_ehdr *)skb_push(skb, ehsz); /* Obtain a seqno first: * Use the key seqno (= cluster wise) if dest is unknown or we're in * cluster key mode, otherwise it's better for a per-peer seqno! */ if (!__rx || aead->mode == CLUSTER_KEY) seqno = atomic64_inc_return(&aead->seqno); else seqno = atomic64_inc_return(&__rx->sndnxt); /* Revoke the key if seqno is wrapped around */ if (unlikely(!seqno)) return tipc_crypto_key_revoke(net, tx_key); /* Word 1-2 */ ehdr->seqno = cpu_to_be64(seqno); /* Words 0, 3- */ ehdr->version = TIPC_EVERSION; ehdr->user = 0; ehdr->keepalive = 0; ehdr->tx_key = tx_key; ehdr->destined = (__rx) ? 1 : 0; ehdr->rx_key_active = (__rx) ? __rx->key.active : 0; ehdr->rx_nokey = (__rx) ? __rx->nokey : 0; ehdr->master_key = aead->crypto->key_master; ehdr->reserved_1 = 0; ehdr->reserved_2 = 0; switch (user) { case LINK_CONFIG: ehdr->user = LINK_CONFIG; memcpy(ehdr->id, tipc_own_id(net), NODE_ID_LEN); break; default: if (user == LINK_PROTOCOL && msg_type(hdr) == STATE_MSG) { ehdr->user = LINK_PROTOCOL; ehdr->keepalive = msg_is_keepalive(hdr); } ehdr->addr = hdr->hdr[3]; break; } return ehsz; } static inline void tipc_crypto_key_set_state(struct tipc_crypto *c, u8 new_passive, u8 new_active, u8 new_pending) { struct tipc_key old = c->key; char buf[32]; c->key.keys = ((new_passive & KEY_MASK) << (KEY_BITS * 2)) | ((new_active & KEY_MASK) << (KEY_BITS)) | ((new_pending & KEY_MASK)); pr_debug("%s: key changing %s ::%pS\n", c->name, tipc_key_change_dump(old, c->key, buf), __builtin_return_address(0)); } /** * tipc_crypto_key_init - Initiate a new user / AEAD key * @c: TIPC crypto to which new key is attached * @ukey: the user key * @mode: the key mode (CLUSTER_KEY or PER_NODE_KEY) * @master_key: specify this is a cluster master key * * A new TIPC AEAD key will be allocated and initiated with the specified user * key, then attached to the TIPC crypto. * * Return: new key id in case of success, otherwise: < 0 */ int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey, u8 mode, bool master_key) { struct tipc_aead *aead = NULL; int rc = 0; /* Initiate with the new user key */ rc = tipc_aead_init(&aead, ukey, mode); /* Attach it to the crypto */ if (likely(!rc)) { rc = tipc_crypto_key_attach(c, aead, 0, master_key); if (rc < 0) tipc_aead_free(&aead->rcu); } return rc; } /** * tipc_crypto_key_attach - Attach a new AEAD key to TIPC crypto * @c: TIPC crypto to which the new AEAD key is attached * @aead: the new AEAD key pointer * @pos: desired slot in the crypto key array, = 0 if any! * @master_key: specify this is a cluster master key * * Return: new key id in case of success, otherwise: -EBUSY */ static int tipc_crypto_key_attach(struct tipc_crypto *c, struct tipc_aead *aead, u8 pos, bool master_key) { struct tipc_key key; int rc = -EBUSY; u8 new_key; spin_lock_bh(&c->lock); key = c->key; if (master_key) { new_key = KEY_MASTER; goto attach; } if (key.active && key.passive) goto exit; if (key.pending) { if (tipc_aead_users(c->aead[key.pending]) > 0) goto exit; /* if (pos): ok with replacing, will be aligned when needed */ /* Replace it */ new_key = key.pending; } else { if (pos) { if (key.active && pos != key_next(key.active)) { key.passive = pos; new_key = pos; goto attach; } else if (!key.active && !key.passive) { key.pending = pos; new_key = pos; goto attach; } } key.pending = key_next(key.active ?: key.passive); new_key = key.pending; } attach: aead->crypto = c; aead->gen = (is_tx(c)) ? ++c->key_gen : c->key_gen; tipc_aead_rcu_replace(c->aead[new_key], aead, &c->lock); if (likely(c->key.keys != key.keys)) tipc_crypto_key_set_state(c, key.passive, key.active, key.pending); c->working = 1; c->nokey = 0; c->key_master |= master_key; rc = new_key; exit: spin_unlock_bh(&c->lock); return rc; } void tipc_crypto_key_flush(struct tipc_crypto *c) { struct tipc_crypto *tx, *rx; int k; spin_lock_bh(&c->lock); if (is_rx(c)) { /* Try to cancel pending work */ rx = c; tx = tipc_net(rx->net)->crypto_tx; if (cancel_delayed_work(&rx->work)) { kfree(rx->skey); rx->skey = NULL; atomic_xchg(&rx->key_distr, 0); tipc_node_put(rx->node); } /* RX stopping => decrease TX key users if any */ k = atomic_xchg(&rx->peer_rx_active, 0); if (k) { tipc_aead_users_dec(tx->aead[k], 0); /* Mark the point TX key users changed */ tx->timer1 = jiffies; } } c->flags = 0; tipc_crypto_key_set_state(c, 0, 0, 0); for (k = KEY_MIN; k <= KEY_MAX; k++) tipc_crypto_key_detach(c->aead[k], &c->lock); atomic64_set(&c->sndnxt, 0); spin_unlock_bh(&c->lock); } /** * tipc_crypto_key_try_align - Align RX keys if possible * @rx: RX crypto handle * @new_pending: new pending slot if aligned (= TX key from peer) * * Peer has used an unknown key slot, this only happens when peer has left and * rejoned, or we are newcomer. * That means, there must be no active key but a pending key at unaligned slot. * If so, we try to move the pending key to the new slot. * Note: A potential passive key can exist, it will be shifted correspondingly! * * Return: "true" if key is successfully aligned, otherwise "false" */ static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending) { struct tipc_aead *tmp1, *tmp2 = NULL; struct tipc_key key; bool aligned = false; u8 new_passive = 0; int x; spin_lock(&rx->lock); key = rx->key; if (key.pending == new_pending) { aligned = true; goto exit; } if (key.active) goto exit; if (!key.pending) goto exit; if (tipc_aead_users(rx->aead[key.pending]) > 0) goto exit; /* Try to "isolate" this pending key first */ tmp1 = tipc_aead_rcu_ptr(rx->aead[key.pending], &rx->lock); if (!refcount_dec_if_one(&tmp1->refcnt)) goto exit; rcu_assign_pointer(rx->aead[key.pending], NULL); /* Move passive key if any */ if (key.passive) { tmp2 = rcu_replace_pointer(rx->aead[key.passive], tmp2, lockdep_is_held(&rx->lock)); x = (key.passive - key.pending + new_pending) % KEY_MAX; new_passive = (x <= 0) ? x + KEY_MAX : x; } /* Re-allocate the key(s) */ tipc_crypto_key_set_state(rx, new_passive, 0, new_pending); rcu_assign_pointer(rx->aead[new_pending], tmp1); if (new_passive) rcu_assign_pointer(rx->aead[new_passive], tmp2); refcount_set(&tmp1->refcnt, 1); aligned = true; pr_info_ratelimited("%s: key[%d] -> key[%d]\n", rx->name, key.pending, new_pending); exit: spin_unlock(&rx->lock); return aligned; } /** * tipc_crypto_key_pick_tx - Pick one TX key for message decryption * @tx: TX crypto handle * @rx: RX crypto handle (can be NULL) * @skb: the message skb which will be decrypted later * @tx_key: peer TX key id * * This function looks up the existing TX keys and pick one which is suitable * for the message decryption, that must be a cluster key and not used before * on the same message (i.e. recursive). * * Return: the TX AEAD key handle in case of success, otherwise NULL */ static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx, struct tipc_crypto *rx, struct sk_buff *skb, u8 tx_key) { struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(skb); struct tipc_aead *aead = NULL; struct tipc_key key = tx->key; u8 k, i = 0; /* Initialize data if not yet */ if (!skb_cb->tx_clone_deferred) { skb_cb->tx_clone_deferred = 1; memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx)); } skb_cb->tx_clone_ctx.rx = rx; if (++skb_cb->tx_clone_ctx.recurs > 2) return NULL; /* Pick one TX key */ spin_lock(&tx->lock); if (tx_key == KEY_MASTER) { aead = tipc_aead_rcu_ptr(tx->aead[KEY_MASTER], &tx->lock); goto done; } do { k = (i == 0) ? key.pending : ((i == 1) ? key.active : key.passive); if (!k) continue; aead = tipc_aead_rcu_ptr(tx->aead[k], &tx->lock); if (!aead) continue; if (aead->mode != CLUSTER_KEY || aead == skb_cb->tx_clone_ctx.last) { aead = NULL; continue; } /* Ok, found one cluster key */ skb_cb->tx_clone_ctx.last = aead; WARN_ON(skb->next); skb->next = skb_clone(skb, GFP_ATOMIC); if (unlikely(!skb->next)) pr_warn("Failed to clone skb for next round if any\n"); break; } while (++i < 3); done: if (likely(aead)) WARN_ON(!refcount_inc_not_zero(&aead->refcnt)); spin_unlock(&tx->lock); return aead; } /** * tipc_crypto_key_synch: Synch own key data according to peer key status * @rx: RX crypto handle * @skb: TIPCv2 message buffer (incl. the ehdr from peer) * * This function updates the peer node related data as the peer RX active key * has changed, so the number of TX keys' users on this node are increased and * decreased correspondingly. * * It also considers if peer has no key, then we need to make own master key * (if any) taking over i.e. starting grace period and also trigger key * distributing process. * * The "per-peer" sndnxt is also reset when the peer key has switched. */ static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb) { struct tipc_ehdr *ehdr = (struct tipc_ehdr *)skb_network_header(skb); struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx; struct tipc_msg *hdr = buf_msg(skb); u32 self = tipc_own_addr(rx->net); u8 cur, new; unsigned long delay; /* Update RX 'key_master' flag according to peer, also mark "legacy" if * a peer has no master key. */ rx->key_master = ehdr->master_key; if (!rx->key_master) tx->legacy_user = 1; /* For later cases, apply only if message is destined to this node */ if (!ehdr->destined || msg_short(hdr) || msg_destnode(hdr) != self) return; /* Case 1: Peer has no keys, let's make master key take over */ if (ehdr->rx_nokey) { /* Set or extend grace period */ tx->timer2 = jiffies; /* Schedule key distributing for the peer if not yet */ if (tx->key.keys && !atomic_cmpxchg(&rx->key_distr, 0, KEY_DISTR_SCHED)) { get_random_bytes(&delay, 2); delay %= 5; delay = msecs_to_jiffies(500 * ++delay); if (queue_delayed_work(tx->wq, &rx->work, delay)) tipc_node_get(rx->node); } } else { /* Cancel a pending key distributing if any */ atomic_xchg(&rx->key_distr, 0); } /* Case 2: Peer RX active key has changed, let's update own TX users */ cur = atomic_read(&rx->peer_rx_active); new = ehdr->rx_key_active; if (tx->key.keys && cur != new && atomic_cmpxchg(&rx->peer_rx_active, cur, new) == cur) { if (new) tipc_aead_users_inc(tx->aead[new], INT_MAX); if (cur) tipc_aead_users_dec(tx->aead[cur], 0); atomic64_set(&rx->sndnxt, 0); /* Mark the point TX key users changed */ tx->timer1 = jiffies; pr_debug("%s: key users changed %d-- %d++, peer %s\n", tx->name, cur, new, rx->name); } } static int tipc_crypto_key_revoke(struct net *net, u8 tx_key) { struct tipc_crypto *tx = tipc_net(net)->crypto_tx; struct tipc_key key; spin_lock(&tx->lock); key = tx->key; WARN_ON(!key.active || tx_key != key.active); /* Free the active key */ tipc_crypto_key_set_state(tx, key.passive, 0, key.pending); tipc_crypto_key_detach(tx->aead[key.active], &tx->lock); spin_unlock(&tx->lock); pr_warn("%s: key is revoked\n", tx->name); return -EKEYREVOKED; } int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net, struct tipc_node *node) { struct tipc_crypto *c; if (*crypto) return -EEXIST; /* Allocate crypto */ c = kzalloc(sizeof(*c), GFP_ATOMIC); if (!c) return -ENOMEM; /* Allocate workqueue on TX */ if (!node) { c->wq = alloc_ordered_workqueue("tipc_crypto", 0); if (!c->wq) { kfree(c); return -ENOMEM; } } /* Allocate statistic structure */ c->stats = alloc_percpu_gfp(struct tipc_crypto_stats, GFP_ATOMIC); if (!c->stats) { kfree_sensitive(c); return -ENOMEM; } c->flags = 0; c->net = net; c->node = node; get_random_bytes(&c->key_gen, 2); tipc_crypto_key_set_state(c, 0, 0, 0); atomic_set(&c->key_distr, 0); atomic_set(&c->peer_rx_active, 0); atomic64_set(&c->sndnxt, 0); c->timer1 = jiffies; c->timer2 = jiffies; spin_lock_init(&c->lock); scnprintf(c->name, 48, "%s(%s)", (is_rx(c)) ? "RX" : "TX", (is_rx(c)) ? tipc_node_get_id_str(c->node) : tipc_own_id_string(c->net)); if (is_rx(c)) INIT_DELAYED_WORK(&c->work, tipc_crypto_work_rx); *crypto = c; return 0; } void tipc_crypto_stop(struct tipc_crypto **crypto) { struct tipc_crypto *c = *crypto; u8 k; if (!c) return; /* Flush any queued works & destroy wq */ if (is_tx(c)) destroy_workqueue(c->wq); /* Release AEAD keys */ rcu_read_lock(); for (k = KEY_MIN; k <= KEY_MAX; k++) tipc_aead_put(rcu_dereference(c->aead[k])); rcu_read_unlock(); pr_debug("%s: has been stopped\n", c->name); /* Free this crypto statistics */ free_percpu(c->stats); *crypto = NULL; kfree_sensitive(c); } void tipc_crypto_timeout(struct tipc_crypto *rx) { struct tipc_net *tn = tipc_net(rx->net); struct tipc_crypto *tx = tn->crypto_tx; struct tipc_key key; int cmd; /* TX pending: taking all users & stable -> active */ spin_lock(&tx->lock); key = tx->key; if (key.active && tipc_aead_users(tx->aead[key.active]) > 0) goto s1; if (!key.pending || tipc_aead_users(tx->aead[key.pending]) <= 0) goto s1; if (time_before(jiffies, tx->timer1 + TIPC_TX_LASTING_TIME)) goto s1; tipc_crypto_key_set_state(tx, key.passive, key.pending, 0); if (key.active) tipc_crypto_key_detach(tx->aead[key.active], &tx->lock); this_cpu_inc(tx->stats->stat[STAT_SWITCHES]); pr_info("%s: key[%d] is activated\n", tx->name, key.pending); s1: spin_unlock(&tx->lock); /* RX pending: having user -> active */ spin_lock(&rx->lock); key = rx->key; if (!key.pending || tipc_aead_users(rx->aead[key.pending]) <= 0) goto s2; if (key.active) key.passive = key.active; key.active = key.pending; rx->timer2 = jiffies; tipc_crypto_key_set_state(rx, key.passive, key.active, 0); this_cpu_inc(rx->stats->stat[STAT_SWITCHES]); pr_info("%s: key[%d] is activated\n", rx->name, key.pending); goto s5; s2: /* RX pending: not working -> remove */ if (!key.pending || tipc_aead_users(rx->aead[key.pending]) > -10) goto s3; tipc_crypto_key_set_state(rx, key.passive, key.active, 0); tipc_crypto_key_detach(rx->aead[key.pending], &rx->lock); pr_debug("%s: key[%d] is removed\n", rx->name, key.pending); goto s5; s3: /* RX active: timed out or no user -> pending */ if (!key.active) goto s4; if (time_before(jiffies, rx->timer1 + TIPC_RX_ACTIVE_LIM) && tipc_aead_users(rx->aead[key.active]) > 0) goto s4; if (key.pending) key.passive = key.active; else key.pending = key.active; rx->timer2 = jiffies; tipc_crypto_key_set_state(rx, key.passive, 0, key.pending); tipc_aead_users_set(rx->aead[key.pending], 0); pr_debug("%s: key[%d] is deactivated\n", rx->name, key.active); goto s5; s4: /* RX passive: outdated or not working -> free */ if (!key.passive) goto s5; if (time_before(jiffies, rx->timer2 + TIPC_RX_PASSIVE_LIM) && tipc_aead_users(rx->aead[key.passive]) > -10) goto s5; tipc_crypto_key_set_state(rx, 0, key.active, key.pending); tipc_crypto_key_detach(rx->aead[key.passive], &rx->lock); pr_debug("%s: key[%d] is freed\n", rx->name, key.passive); s5: spin_unlock(&rx->lock); /* Relax it here, the flag will be set again if it really is, but only * when we are not in grace period for safety! */ if (time_after(jiffies, tx->timer2 + TIPC_TX_GRACE_PERIOD)) tx->legacy_user = 0; /* Limit max_tfms & do debug commands if needed */ if (likely(sysctl_tipc_max_tfms <= TIPC_MAX_TFMS_LIM)) return; cmd = sysctl_tipc_max_tfms; sysctl_tipc_max_tfms = TIPC_MAX_TFMS_DEF; tipc_crypto_do_cmd(rx->net, cmd); } static inline void tipc_crypto_clone_msg(struct net *net, struct sk_buff *_skb, struct tipc_bearer *b, struct tipc_media_addr *dst, struct tipc_node *__dnode, u8 type) { struct sk_buff *skb; skb = skb_clone(_skb, GFP_ATOMIC); if (skb) { TIPC_SKB_CB(skb)->xmit_type = type; tipc_crypto_xmit(net, &skb, b, dst, __dnode); if (skb) b->media->send_msg(net, skb, b, dst); } } /** * tipc_crypto_xmit - Build & encrypt TIPC message for xmit * @net: struct net * @skb: input/output message skb pointer * @b: bearer used for xmit later * @dst: destination media address * @__dnode: destination node for reference if any * * First, build an encryption message header on the top of the message, then * encrypt the original TIPC message by using the pending, master or active * key with this preference order. * If the encryption is successful, the encrypted skb is returned directly or * via the callback. * Otherwise, the skb is freed! * * Return: * 0 : the encryption has succeeded (or no encryption) * -EINPROGRESS/-EBUSY : the encryption is ongoing, a callback will be made * -ENOKEK : the encryption has failed due to no key * -EKEYREVOKED : the encryption has failed due to key revoked * -ENOMEM : the encryption has failed due to no memory * < 0 : the encryption has failed due to other reasons */ int tipc_crypto_xmit(struct net *net, struct sk_buff **skb, struct tipc_bearer *b, struct tipc_media_addr *dst, struct tipc_node *__dnode) { struct tipc_crypto *__rx = tipc_node_crypto_rx(__dnode); struct tipc_crypto *tx = tipc_net(net)->crypto_tx; struct tipc_crypto_stats __percpu *stats = tx->stats; struct tipc_msg *hdr = buf_msg(*skb); struct tipc_key key = tx->key; struct tipc_aead *aead = NULL; u32 user = msg_user(hdr); u32 type = msg_type(hdr); int rc = -ENOKEY; u8 tx_key = 0; /* No encryption? */ if (!tx->working) return 0; /* Pending key if peer has active on it or probing time */ if (unlikely(key.pending)) { tx_key = key.pending; if (!tx->key_master && !key.active) goto encrypt; if (__rx && atomic_read(&__rx->peer_rx_active) == tx_key) goto encrypt; if (TIPC_SKB_CB(*skb)->xmit_type == SKB_PROBING) { pr_debug("%s: probing for key[%d]\n", tx->name, key.pending); goto encrypt; } if (user == LINK_CONFIG || user == LINK_PROTOCOL) tipc_crypto_clone_msg(net, *skb, b, dst, __dnode, SKB_PROBING); } /* Master key if this is a *vital* message or in grace period */ if (tx->key_master) { tx_key = KEY_MASTER; if (!key.active) goto encrypt; if (TIPC_SKB_CB(*skb)->xmit_type == SKB_GRACING) { pr_debug("%s: gracing for msg (%d %d)\n", tx->name, user, type); goto encrypt; } if (user == LINK_CONFIG || (user == LINK_PROTOCOL && type == RESET_MSG) || (user == MSG_CRYPTO && type == KEY_DISTR_MSG) || time_before(jiffies, tx->timer2 + TIPC_TX_GRACE_PERIOD)) { if (__rx && __rx->key_master && !atomic_read(&__rx->peer_rx_active)) goto encrypt; if (!__rx) { if (likely(!tx->legacy_user)) goto encrypt; tipc_crypto_clone_msg(net, *skb, b, dst, __dnode, SKB_GRACING); } } } /* Else, use the active key if any */ if (likely(key.active)) { tx_key = key.active; goto encrypt; } goto exit; encrypt: aead = tipc_aead_get(tx->aead[tx_key]); if (unlikely(!aead)) goto exit; rc = tipc_ehdr_build(net, aead, tx_key, *skb, __rx); if (likely(rc > 0)) rc = tipc_aead_encrypt(aead, *skb, b, dst, __dnode); exit: switch (rc) { case 0: this_cpu_inc(stats->stat[STAT_OK]); break; case -EINPROGRESS: case -EBUSY: this_cpu_inc(stats->stat[STAT_ASYNC]); *skb = NULL; return rc; default: this_cpu_inc(stats->stat[STAT_NOK]); if (rc == -ENOKEY) this_cpu_inc(stats->stat[STAT_NOKEYS]); else if (rc == -EKEYREVOKED) this_cpu_inc(stats->stat[STAT_BADKEYS]); kfree_skb(*skb); *skb = NULL; break; } tipc_aead_put(aead); return rc; } /** * tipc_crypto_rcv - Decrypt an encrypted TIPC message from peer * @net: struct net * @rx: RX crypto handle * @skb: input/output message skb pointer * @b: bearer where the message has been received * * If the decryption is successful, the decrypted skb is returned directly or * as the callback, the encryption header and auth tag will be trimed out * before forwarding to tipc_rcv() via the tipc_crypto_rcv_complete(). * Otherwise, the skb will be freed! * Note: RX key(s) can be re-aligned, or in case of no key suitable, TX * cluster key(s) can be taken for decryption (- recursive). * * Return: * 0 : the decryption has successfully completed * -EINPROGRESS/-EBUSY : the decryption is ongoing, a callback will be made * -ENOKEY : the decryption has failed due to no key * -EBADMSG : the decryption has failed due to bad message * -ENOMEM : the decryption has failed due to no memory * < 0 : the decryption has failed due to other reasons */ int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx, struct sk_buff **skb, struct tipc_bearer *b) { struct tipc_crypto *tx = tipc_net(net)->crypto_tx; struct tipc_crypto_stats __percpu *stats; struct tipc_aead *aead = NULL; struct tipc_key key; int rc = -ENOKEY; u8 tx_key, n; tx_key = ((struct tipc_ehdr *)(*skb)->data)->tx_key; /* New peer? * Let's try with TX key (i.e. cluster mode) & verify the skb first! */ if (unlikely(!rx || tx_key == KEY_MASTER)) goto pick_tx; /* Pick RX key according to TX key if any */ key = rx->key; if (tx_key == key.active || tx_key == key.pending || tx_key == key.passive) goto decrypt; /* Unknown key, let's try to align RX key(s) */ if (tipc_crypto_key_try_align(rx, tx_key)) goto decrypt; pick_tx: /* No key suitable? Try to pick one from TX... */ aead = tipc_crypto_key_pick_tx(tx, rx, *skb, tx_key); if (aead) goto decrypt; goto exit; decrypt: rcu_read_lock(); if (!aead) aead = tipc_aead_get(rx->aead[tx_key]); rc = tipc_aead_decrypt(net, aead, *skb, b); rcu_read_unlock(); exit: stats = ((rx) ?: tx)->stats; switch (rc) { case 0: this_cpu_inc(stats->stat[STAT_OK]); break; case -EINPROGRESS: case -EBUSY: this_cpu_inc(stats->stat[STAT_ASYNC]); *skb = NULL; return rc; default: this_cpu_inc(stats->stat[STAT_NOK]); if (rc == -ENOKEY) { kfree_skb(*skb); *skb = NULL; if (rx) { /* Mark rx->nokey only if we dont have a * pending received session key, nor a newer * one i.e. in the next slot. */ n = key_next(tx_key); rx->nokey = !(rx->skey || rcu_access_pointer(rx->aead[n])); pr_debug_ratelimited("%s: nokey %d, key %d/%x\n", rx->name, rx->nokey, tx_key, rx->key.keys); tipc_node_put(rx->node); } this_cpu_inc(stats->stat[STAT_NOKEYS]); return rc; } else if (rc == -EBADMSG) { this_cpu_inc(stats->stat[STAT_BADMSGS]); } break; } tipc_crypto_rcv_complete(net, aead, b, skb, rc); return rc; } static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead, struct tipc_bearer *b, struct sk_buff **skb, int err) { struct tipc_skb_cb *skb_cb = TIPC_SKB_CB(*skb); struct tipc_crypto *rx = aead->crypto; struct tipc_aead *tmp = NULL; struct tipc_ehdr *ehdr; struct tipc_node *n; /* Is this completed by TX? */ if (unlikely(is_tx(aead->crypto))) { rx = skb_cb->tx_clone_ctx.rx; pr_debug("TX->RX(%s): err %d, aead %p, skb->next %p, flags %x\n", (rx) ? tipc_node_get_id_str(rx->node) : "-", err, aead, (*skb)->next, skb_cb->flags); pr_debug("skb_cb [recurs %d, last %p], tx->aead [%p %p %p]\n", skb_cb->tx_clone_ctx.recurs, skb_cb->tx_clone_ctx.last, aead->crypto->aead[1], aead->crypto->aead[2], aead->crypto->aead[3]); if (unlikely(err)) { if (err == -EBADMSG && (*skb)->next) tipc_rcv(net, (*skb)->next, b); goto free_skb; } if (likely((*skb)->next)) { kfree_skb((*skb)->next); (*skb)->next = NULL; } ehdr = (struct tipc_ehdr *)(*skb)->data; if (!rx) { WARN_ON(ehdr->user != LINK_CONFIG); n = tipc_node_create(net, 0, ehdr->id, 0xffffu, 0, true); rx = tipc_node_crypto_rx(n); if (unlikely(!rx)) goto free_skb; } /* Ignore cloning if it was TX master key */ if (ehdr->tx_key == KEY_MASTER) goto rcv; if (tipc_aead_clone(&tmp, aead) < 0) goto rcv; if (tipc_crypto_key_attach(rx, tmp, ehdr->tx_key, false) < 0) { tipc_aead_free(&tmp->rcu); goto rcv; } tipc_aead_put(aead); aead = tipc_aead_get(tmp); } if (unlikely(err)) { tipc_aead_users_dec(aead, INT_MIN); goto free_skb; } /* Set the RX key's user */ tipc_aead_users_set(aead, 1); /* Mark this point, RX works */ rx->timer1 = jiffies; rcv: /* Remove ehdr & auth. tag prior to tipc_rcv() */ ehdr = (struct tipc_ehdr *)(*skb)->data; /* Mark this point, RX passive still works */ if (rx->key.passive && ehdr->tx_key == rx->key.passive) rx->timer2 = jiffies; skb_reset_network_header(*skb); skb_pull(*skb, tipc_ehdr_size(ehdr)); pskb_trim(*skb, (*skb)->len - aead->authsize); /* Validate TIPCv2 message */ if (unlikely(!tipc_msg_validate(skb))) { pr_err_ratelimited("Packet dropped after decryption!\n"); goto free_skb; } /* Ok, everything's fine, try to synch own keys according to peers' */ tipc_crypto_key_synch(rx, *skb); /* Mark skb decrypted */ skb_cb->decrypted = 1; /* Clear clone cxt if any */ if (likely(!skb_cb->tx_clone_deferred)) goto exit; skb_cb->tx_clone_deferred = 0; memset(&skb_cb->tx_clone_ctx, 0, sizeof(skb_cb->tx_clone_ctx)); goto exit; free_skb: kfree_skb(*skb); *skb = NULL; exit: tipc_aead_put(aead); if (rx) tipc_node_put(rx->node); } static void tipc_crypto_do_cmd(struct net *net, int cmd) { struct tipc_net *tn = tipc_net(net); struct tipc_crypto *tx = tn->crypto_tx, *rx; struct list_head *p; unsigned int stat; int i, j, cpu; char buf[200]; /* Currently only one command is supported */ switch (cmd) { case 0xfff1: goto print_stats; default: return; } print_stats: /* Print a header */ pr_info("\n=============== TIPC Crypto Statistics ===============\n\n"); /* Print key status */ pr_info("Key status:\n"); pr_info("TX(%7.7s)\n%s", tipc_own_id_string(net), tipc_crypto_key_dump(tx, buf)); rcu_read_lock(); for (p = tn->node_list.next; p != &tn->node_list; p = p->next) { rx = tipc_node_crypto_rx_by_list(p); pr_info("RX(%7.7s)\n%s", tipc_node_get_id_str(rx->node), tipc_crypto_key_dump(rx, buf)); } rcu_read_unlock(); /* Print crypto statistics */ for (i = 0, j = 0; i < MAX_STATS; i++) j += scnprintf(buf + j, 200 - j, "|%11s ", hstats[i]); pr_info("Counter %s", buf); memset(buf, '-', 115); buf[115] = '\0'; pr_info("%s\n", buf); j = scnprintf(buf, 200, "TX(%7.7s) ", tipc_own_id_string(net)); for_each_possible_cpu(cpu) { for (i = 0; i < MAX_STATS; i++) { stat = per_cpu_ptr(tx->stats, cpu)->stat[i]; j += scnprintf(buf + j, 200 - j, "|%11d ", stat); } pr_info("%s", buf); j = scnprintf(buf, 200, "%12s", " "); } rcu_read_lock(); for (p = tn->node_list.next; p != &tn->node_list; p = p->next) { rx = tipc_node_crypto_rx_by_list(p); j = scnprintf(buf, 200, "RX(%7.7s) ", tipc_node_get_id_str(rx->node)); for_each_possible_cpu(cpu) { for (i = 0; i < MAX_STATS; i++) { stat = per_cpu_ptr(rx->stats, cpu)->stat[i]; j += scnprintf(buf + j, 200 - j, "|%11d ", stat); } pr_info("%s", buf); j = scnprintf(buf, 200, "%12s", " "); } } rcu_read_unlock(); pr_info("\n======================== Done ========================\n"); } static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf) { struct tipc_key key = c->key; struct tipc_aead *aead; int k, i = 0; char *s; for (k = KEY_MIN; k <= KEY_MAX; k++) { if (k == KEY_MASTER) { if (is_rx(c)) continue; if (time_before(jiffies, c->timer2 + TIPC_TX_GRACE_PERIOD)) s = "ACT"; else s = "PAS"; } else { if (k == key.passive) s = "PAS"; else if (k == key.active) s = "ACT"; else if (k == key.pending) s = "PEN"; else s = "-"; } i += scnprintf(buf + i, 200 - i, "\tKey%d: %s", k, s); rcu_read_lock(); aead = rcu_dereference(c->aead[k]); if (aead) i += scnprintf(buf + i, 200 - i, "{\"0x...%s\", \"%s\"}/%d:%d", aead->hint, (aead->mode == CLUSTER_KEY) ? "c" : "p", atomic_read(&aead->users), refcount_read(&aead->refcnt)); rcu_read_unlock(); i += scnprintf(buf + i, 200 - i, "\n"); } if (is_rx(c)) i += scnprintf(buf + i, 200 - i, "\tPeer RX active: %d\n", atomic_read(&c->peer_rx_active)); return buf; } static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new, char *buf) { struct tipc_key *key = &old; int k, i = 0; char *s; /* Output format: "[%s %s %s] -> [%s %s %s]", max len = 32 */ again: i += scnprintf(buf + i, 32 - i, "["); for (k = KEY_1; k <= KEY_3; k++) { if (k == key->passive) s = "pas"; else if (k == key->active) s = "act"; else if (k == key->pending) s = "pen"; else s = "-"; i += scnprintf(buf + i, 32 - i, (k != KEY_3) ? "%s " : "%s", s); } if (key != &new) { i += scnprintf(buf + i, 32 - i, "] -> "); key = &new; goto again; } i += scnprintf(buf + i, 32 - i, "]"); return buf; } /** * tipc_crypto_msg_rcv - Common 'MSG_CRYPTO' processing point * @net: the struct net * @skb: the receiving message buffer */ void tipc_crypto_msg_rcv(struct net *net, struct sk_buff *skb) { struct tipc_crypto *rx; struct tipc_msg *hdr; if (unlikely(skb_linearize(skb))) goto exit; hdr = buf_msg(skb); rx = tipc_node_crypto_rx_by_addr(net, msg_prevnode(hdr)); if (unlikely(!rx)) goto exit; switch (msg_type(hdr)) { case KEY_DISTR_MSG: if (tipc_crypto_key_rcv(rx, hdr)) goto exit; break; default: break; } tipc_node_put(rx->node); exit: kfree_skb(skb); } /** * tipc_crypto_key_distr - Distribute a TX key * @tx: the TX crypto * @key: the key's index * @dest: the destination tipc node, = NULL if distributing to all nodes * * Return: 0 in case of success, otherwise < 0 */ int tipc_crypto_key_distr(struct tipc_crypto *tx, u8 key, struct tipc_node *dest) { struct tipc_aead *aead; u32 dnode = tipc_node_get_addr(dest); int rc = -ENOKEY; if (!sysctl_tipc_key_exchange_enabled) return 0; if (key) { rcu_read_lock(); aead = tipc_aead_get(tx->aead[key]); if (likely(aead)) { rc = tipc_crypto_key_xmit(tx->net, aead->key, aead->gen, aead->mode, dnode); tipc_aead_put(aead); } rcu_read_unlock(); } return rc; } /** * tipc_crypto_key_xmit - Send a session key * @net: the struct net * @skey: the session key to be sent * @gen: the key's generation * @mode: the key's mode * @dnode: the destination node address, = 0 if broadcasting to all nodes * * The session key 'skey' is packed in a TIPC v2 'MSG_CRYPTO/KEY_DISTR_MSG' * as its data section, then xmit-ed through the uc/bc link. * * Return: 0 in case of success, otherwise < 0 */ static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey, u16 gen, u8 mode, u32 dnode) { struct sk_buff_head pkts; struct tipc_msg *hdr; struct sk_buff *skb; u16 size, cong_link_cnt; u8 *data; int rc; size = tipc_aead_key_size(skey); skb = tipc_buf_acquire(INT_H_SIZE + size, GFP_ATOMIC); if (!skb) return -ENOMEM; hdr = buf_msg(skb); tipc_msg_init(tipc_own_addr(net), hdr, MSG_CRYPTO, KEY_DISTR_MSG, INT_H_SIZE, dnode); msg_set_size(hdr, INT_H_SIZE + size); msg_set_key_gen(hdr, gen); msg_set_key_mode(hdr, mode); data = msg_data(hdr); *((__be32 *)(data + TIPC_AEAD_ALG_NAME)) = htonl(skey->keylen); memcpy(data, skey->alg_name, TIPC_AEAD_ALG_NAME); memcpy(data + TIPC_AEAD_ALG_NAME + sizeof(__be32), skey->key, skey->keylen); __skb_queue_head_init(&pkts); __skb_queue_tail(&pkts, skb); if (dnode) rc = tipc_node_xmit(net, &pkts, dnode, 0); else rc = tipc_bcast_xmit(net, &pkts, &cong_link_cnt); return rc; } /** * tipc_crypto_key_rcv - Receive a session key * @rx: the RX crypto * @hdr: the TIPC v2 message incl. the receiving session key in its data * * This function retrieves the session key in the message from peer, then * schedules a RX work to attach the key to the corresponding RX crypto. * * Return: "true" if the key has been scheduled for attaching, otherwise * "false". */ static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr) { struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx; struct tipc_aead_key *skey = NULL; u16 key_gen = msg_key_gen(hdr); u16 size = msg_data_sz(hdr); u8 *data = msg_data(hdr); spin_lock(&rx->lock); if (unlikely(rx->skey || (key_gen == rx->key_gen && rx->key.keys))) { pr_err("%s: key existed <%p>, gen %d vs %d\n", rx->name, rx->skey, key_gen, rx->key_gen); goto exit; } /* Allocate memory for the key */ skey = kmalloc(size, GFP_ATOMIC); if (unlikely(!skey)) { pr_err("%s: unable to allocate memory for skey\n", rx->name); goto exit; } /* Copy key from msg data */ skey->keylen = ntohl(*((__be32 *)(data + TIPC_AEAD_ALG_NAME))); memcpy(skey->alg_name, data, TIPC_AEAD_ALG_NAME); memcpy(skey->key, data + TIPC_AEAD_ALG_NAME + sizeof(__be32), skey->keylen); /* Sanity check */ if (unlikely(size != tipc_aead_key_size(skey))) { kfree(skey); skey = NULL; goto exit; } rx->key_gen = key_gen; rx->skey_mode = msg_key_mode(hdr); rx->skey = skey; rx->nokey = 0; mb(); /* for nokey flag */ exit: spin_unlock(&rx->lock); /* Schedule the key attaching on this crypto */ if (likely(skey && queue_delayed_work(tx->wq, &rx->work, 0))) return true; return false; } /** * tipc_crypto_work_rx - Scheduled RX works handler * @work: the struct RX work * * The function processes the previous scheduled works i.e. distributing TX key * or attaching a received session key on RX crypto. */ static void tipc_crypto_work_rx(struct work_struct *work) { struct delayed_work *dwork = to_delayed_work(work); struct tipc_crypto *rx = container_of(dwork, struct tipc_crypto, work); struct tipc_crypto *tx = tipc_net(rx->net)->crypto_tx; unsigned long delay = msecs_to_jiffies(5000); bool resched = false; u8 key; int rc; /* Case 1: Distribute TX key to peer if scheduled */ if (atomic_cmpxchg(&rx->key_distr, KEY_DISTR_SCHED, KEY_DISTR_COMPL) == KEY_DISTR_SCHED) { /* Always pick the newest one for distributing */ key = tx->key.pending ?: tx->key.active; rc = tipc_crypto_key_distr(tx, key, rx->node); if (unlikely(rc)) pr_warn("%s: unable to distr key[%d] to %s, err %d\n", tx->name, key, tipc_node_get_id_str(rx->node), rc); /* Sched for key_distr releasing */ resched = true; } else { atomic_cmpxchg(&rx->key_distr, KEY_DISTR_COMPL, 0); } /* Case 2: Attach a pending received session key from peer if any */ if (rx->skey) { rc = tipc_crypto_key_init(rx, rx->skey, rx->skey_mode, false); if (unlikely(rc < 0)) pr_warn("%s: unable to attach received skey, err %d\n", rx->name, rc); switch (rc) { case -EBUSY: case -ENOMEM: /* Resched the key attaching */ resched = true; break; default: synchronize_rcu(); kfree(rx->skey); rx->skey = NULL; break; } } if (resched && queue_delayed_work(tx->wq, &rx->work, delay)) return; tipc_node_put(rx->node); }