From fc1b6d6de2208774efd2a20bf0daddb02d18b1e0 Mon Sep 17 00:00:00 2001 From: Tuong Lien Date: Fri, 8 Nov 2019 12:05:11 +0700 Subject: tipc: introduce TIPC encryption & authentication This commit offers an option to encrypt and authenticate all messaging, including the neighbor discovery messages. The currently most advanced algorithm supported is the AEAD AES-GCM (like IPSec or TLS). All encryption/decryption is done at the bearer layer, just before leaving or after entering TIPC. Supported features: - Encryption & authentication of all TIPC messages (header + data); - Two symmetric-key modes: Cluster and Per-node; - Automatic key switching; - Key-expired revoking (sequence number wrapped); - Lock-free encryption/decryption (RCU); - Asynchronous crypto, Intel AES-NI supported; - Multiple cipher transforms; - Logs & statistics; Two key modes: - Cluster key mode: One single key is used for both TX & RX in all nodes in the cluster. - Per-node key mode: Each nodes in the cluster has one specific TX key. For RX, a node requires its peers' TX key to be able to decrypt the messages from those peers. Key setting from user-space is performed via netlink by a user program (e.g. the iproute2 'tipc' tool). Internal key state machine: Attach Align(RX) +-+ +-+ | V | V +---------+ Attach +---------+ | IDLE |---------------->| PENDING |(user = 0) +---------+ +---------+ A A Switch| A | | | | | | Free(switch/revoked) | | (Free)| +----------------------+ | |Timeout | (TX) | | |(RX) | | | | | | v | +---------+ Switch +---------+ | PASSIVE |<----------------| ACTIVE | +---------+ (RX) +---------+ (user = 1) (user >= 1) The number of TFMs is 10 by default and can be changed via the procfs 'net/tipc/max_tfms'. At this moment, as for simplicity, this file is also used to print the crypto statistics at runtime: echo 0xfff1 > /proc/sys/net/tipc/max_tfms The patch defines a new TIPC version (v7) for the encryption message (- backward compatibility as well). The message is basically encapsulated as follows: +----------------------------------------------------------+ | TIPCv7 encryption | Original TIPCv2 | Authentication | | header | packet (encrypted) | Tag | +----------------------------------------------------------+ The throughput is about ~40% for small messages (compared with non- encryption) and ~9% for large messages. With the support from hardware crypto i.e. the Intel AES-NI CPU instructions, the throughput increases upto ~85% for small messages and ~55% for large messages. By default, the new feature is inactive (i.e. no encryption) until user sets a key for TIPC. There is however also a new option - "TIPC_CRYPTO" in the kernel configuration to enable/disable the new code when needed. MAINTAINERS | add two new files 'crypto.h' & 'crypto.c' in tipc Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller --- net/tipc/link.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) (limited to 'net/tipc/link.c') diff --git a/net/tipc/link.c b/net/tipc/link.c index e7bb4cbb7716..fb72031228c9 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -44,6 +44,7 @@ #include "netlink.h" #include "monitor.h" #include "trace.h" +#include "crypto.h" #include @@ -397,6 +398,15 @@ int tipc_link_mtu(struct tipc_link *l) return l->mtu; } +int tipc_link_mss(struct tipc_link *l) +{ +#ifdef CONFIG_TIPC_CRYPTO + return l->mtu - INT_H_SIZE - EMSG_OVERHEAD; +#else + return l->mtu - INT_H_SIZE; +#endif +} + u16 tipc_link_rcv_nxt(struct tipc_link *l) { return l->rcv_nxt; @@ -948,6 +958,7 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list, u16 seqno = l->snd_nxt; int pkt_cnt = skb_queue_len(list); int imp = msg_importance(hdr); + unsigned int mss = tipc_link_mss(l); unsigned int maxwin = l->window; unsigned int mtu = l->mtu; bool new_bundle; @@ -1000,8 +1011,7 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list, continue; } if (tipc_msg_try_bundle(l->backlog[imp].target_bskb, &skb, - mtu - INT_H_SIZE, l->addr, - &new_bundle)) { + mss, l->addr, &new_bundle)) { if (skb) { /* Keep a ref. to the skb for next try */ l->backlog[imp].target_bskb = skb; @@ -1154,7 +1164,7 @@ static int tipc_link_bc_retrans(struct tipc_link *l, struct tipc_link *r, if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr)) continue; TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM; - _skb = __pskb_copy(skb, LL_MAX_HEADER + MIN_H_SIZE, GFP_ATOMIC); + _skb = pskb_copy(skb, GFP_ATOMIC); if (!_skb) return 0; hdr = buf_msg(_skb); @@ -1430,8 +1440,7 @@ next_gap_ack: if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr)) continue; TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME; - _skb = __pskb_copy(skb, LL_MAX_HEADER + MIN_H_SIZE, - GFP_ATOMIC); + _skb = pskb_copy(skb, GFP_ATOMIC); if (!_skb) continue; hdr = buf_msg(_skb); -- cgit v1.2.3