Re: [PATCH v6 07/21] net/tcp: Add tcp_parse_auth_options()

[kernel test robot]

Hi Dmitry,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 47a2ee5d4a0bda05decdda7be0a77e792cdb09a3]

url:    https://github.com/intel-lab-lkp/linux/commits/Dmitry-Safonov/net-tcp-Prepare-tcp_md5sig_pool-for-TCP-AO/20230513-042734
base:   47a2ee5d4a0bda05decdda7be0a77e792cdb09a3
patch link:    https://lore.kernel.org/r/20230512202311.2845526-8-dima%40arista.com
patch subject: [PATCH v6 07/21] net/tcp: Add tcp_parse_auth_options()
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230513/202305130600.uZymcUzw-lkp@xxxxxxxxx/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/16d692b101c65ae6a5a60530a3461c512f3bc312
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Dmitry-Safonov/net-tcp-Prepare-tcp_md5sig_pool-for-TCP-AO/20230513-042734
        git checkout 16d692b101c65ae6a5a60530a3461c512f3bc312
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash net/ipv4/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202305130600.uZymcUzw-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

   net/ipv4/tcp.c: In function 'tcp_inbound_md5_hash':
>> net/ipv4/tcp.c:4506:24: warning: implicit conversion from 'enum <anonymous>' to 'enum skb_drop_reason' [-Wenum-conversion]
    4506 |                 return true;
         |                        ^~~~


vim +4506 net/ipv4/tcp.c

  4477	
  4478	/* Called with rcu_read_lock() */
  4479	enum skb_drop_reason
  4480	tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
  4481			     const void *saddr, const void *daddr,
  4482			     int family, int dif, int sdif)
  4483	{
  4484		/*
  4485		 * This gets called for each TCP segment that arrives
  4486		 * so we want to be efficient.
  4487		 * We have 3 drop cases:
  4488		 * o No MD5 hash and one expected.
  4489		 * o MD5 hash and we're not expecting one.
  4490		 * o MD5 hash and its wrong.
  4491		 */
  4492		const __u8 *hash_location = NULL;
  4493		struct tcp_md5sig_key *hash_expected;
  4494		const struct tcphdr *th = tcp_hdr(skb);
  4495		const struct tcp_sock *tp = tcp_sk(sk);
  4496		int genhash, l3index;
  4497		u8 newhash[16];
  4498	
  4499		/* sdif set, means packet ingressed via a device
  4500		 * in an L3 domain and dif is set to the l3mdev
  4501		 */
  4502		l3index = sdif ? dif : 0;
  4503	
  4504		hash_expected = tcp_md5_do_lookup(sk, l3index, saddr, family);
  4505		if (tcp_parse_auth_options(th, &hash_location, NULL))
> 4506			return true;
  4507	
  4508		/* We've parsed the options - do we have a hash? */
  4509		if (!hash_expected && !hash_location)
  4510			return SKB_NOT_DROPPED_YET;
  4511	
  4512		if (hash_expected && !hash_location) {
  4513			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
  4514			return SKB_DROP_REASON_TCP_MD5NOTFOUND;
  4515		}
  4516	
  4517		if (!hash_expected && hash_location) {
  4518			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
  4519			return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
  4520		}
  4521	
  4522		/* Check the signature.
  4523		 * To support dual stack listeners, we need to handle
  4524		 * IPv4-mapped case.
  4525		 */
  4526		if (family == AF_INET)
  4527			genhash = tcp_v4_md5_hash_skb(newhash,
  4528						      hash_expected,
  4529						      NULL, skb);
  4530		else
  4531			genhash = tp->af_specific->calc_md5_hash(newhash,
  4532								 hash_expected,
  4533								 NULL, skb);
  4534	
  4535		if (genhash || memcmp(hash_location, newhash, 16) != 0) {
  4536			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
  4537			if (family == AF_INET) {
  4538				net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s L3 index %d\n",
  4539						saddr, ntohs(th->source),
  4540						daddr, ntohs(th->dest),
  4541						genhash ? " tcp_v4_calc_md5_hash failed"
  4542						: "", l3index);
  4543			} else {
  4544				net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n",
  4545						genhash ? "failed" : "mismatch",
  4546						saddr, ntohs(th->source),
  4547						daddr, ntohs(th->dest), l3index);
  4548			}
  4549			return SKB_DROP_REASON_TCP_MD5FAILURE;
  4550		}
  4551		return SKB_NOT_DROPPED_YET;
  4552	}
  4553	EXPORT_SYMBOL(tcp_inbound_md5_hash);
  4554	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests