Add support to inet v4 raw sockets for binding to nonlocal addresses through the IP_FREEBIND and IP_TRANSPARENT socket options, as well as the ipv4.ip_nonlocal_bind kernel parameter.
Add helper function to inet_sock.h to check for bind address validity on the base of the address type and whether nonlocal address are enabled for the socket via any of the sockopts/sysctl, deduplicating checks in ipv4/ping.c, ipv4/af_inet.c, ipv6/af_inet6.c (for mapped v4->v6 addresses), and ipv4/raw.c.
Add test cases with IP[V6]_FREEBIND verifying that both v4 and v6 raw sockets support binding to nonlocal addresses after the change. Add necessary support for the test cases to nettest.
Signed-off-by: Riccardo Paolo Bestetti pbl@bestov.io Reviewed-by: David Ahern dsahern@kernel.org --- 20211117: resending this, as Patchwork didn't pick it up last time
Responding to review by David Ahern (21 March 2021),
Thank you for your review.
Please add test cases to ipv4_addr_bind and ipv6_addr_bind in tools/testing/selftests/net/fcnal-test.sh. The latter will verify if IPv6 works the same or needs a change.
I have added the tests for both v4 and v6. IPv6 raw sockets already supported the functionality (under the IPV6_* sockopts), and the (new) related tests pass, confirming this.
I have not added negative tests (i.e. checking that the same addresses /fail/ to bind without the necessary flags) because I haven't seen such tests for other features. If you feel that's needed, I can look into it.
Also, this check duplicates the ones in __inet_bind and __inet6_bind; it would be good to use an inline helper to reduce the duplication.
Done. The same check was also duplicated in net/ipv4/ping.c, as detailed in the commit message. I have also deduplicated that, if it should have been left alone I'll quickly fire up a v3 and revert that.
Sorry for the delay with v2, had a busy year.
include/net/inet_sock.h | 12 +++++++ net/ipv4/af_inet.c | 7 ++-- net/ipv4/ping.c | 14 +++----- net/ipv4/raw.c | 13 ++++---- net/ipv6/af_inet6.c | 7 ++-- tools/testing/selftests/net/fcnal-test.sh | 40 +++++++++++++++++++++++ tools/testing/selftests/net/nettest.c | 33 ++++++++++++++++++- 7 files changed, 100 insertions(+), 26 deletions(-)
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 89163ef8cf4b..13b05d116f6b 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -373,4 +373,16 @@ static inline bool inet_can_nonlocal_bind(struct net *net, inet->freebind || inet->transparent; }
+static inline bool inet_addr_valid_or_nonlocal(struct net *net, + struct inet_sock *inet, + __be32 addr, + int addr_type) +{ + return inet_can_nonlocal_bind(net, inet) || + addr == htonl(INADDR_ANY) || + addr_type == RTN_LOCAL || + addr_type == RTN_MULTICAST || + addr_type == RTN_BROADCAST; +} + #endif /* _INET_SOCK_H */ diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 1d816a5fd3eb..fb5cf3623e03 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -492,11 +492,8 @@ int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, * is temporarily down) */ err = -EADDRNOTAVAIL; - if (!inet_can_nonlocal_bind(net, inet) && - addr->sin_addr.s_addr != htonl(INADDR_ANY) && - chk_addr_ret != RTN_LOCAL && - chk_addr_ret != RTN_MULTICAST && - chk_addr_ret != RTN_BROADCAST) + if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr, + chk_addr_ret)) goto out;
snum = ntohs(addr->sin_port); diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 1e44a43acfe2..e540b0dcf085 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -311,15 +311,11 @@ static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
- if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) - chk_addr_ret = RTN_LOCAL; - else - chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); - - if ((!inet_can_nonlocal_bind(net, isk) && - chk_addr_ret != RTN_LOCAL) || - chk_addr_ret == RTN_MULTICAST || - chk_addr_ret == RTN_BROADCAST) + chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); + + if (!inet_addr_valid_or_nonlocal(net, inet_sk(sk), + addr->sin_addr.s_addr, + chk_addr_ret)) return -EADDRNOTAVAIL;
#if IS_ENABLED(CONFIG_IPV6) diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c index bb446e60cf58..fa60517372b5 100644 --- a/net/ipv4/raw.c +++ b/net/ipv4/raw.c @@ -717,6 +717,7 @@ static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) { struct inet_sock *inet = inet_sk(sk); struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; + struct net *net = sock_net(sk); u32 tb_id = RT_TABLE_LOCAL; int ret = -EINVAL; int chk_addr_ret; @@ -725,16 +726,16 @@ static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) goto out;
if (sk->sk_bound_dev_if) - tb_id = l3mdev_fib_table_by_index(sock_net(sk), - sk->sk_bound_dev_if) ? : tb_id; + tb_id = l3mdev_fib_table_by_index(net, + sk->sk_bound_dev_if) ? : tb_id;
- chk_addr_ret = inet_addr_type_table(sock_net(sk), addr->sin_addr.s_addr, - tb_id); + chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
ret = -EADDRNOTAVAIL; - if (addr->sin_addr.s_addr && chk_addr_ret != RTN_LOCAL && - chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST) + if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr, + chk_addr_ret)) goto out; + inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr; if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) inet->inet_saddr = 0; /* Use device */ diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index b5878bb8e419..0c557edbbd20 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -337,11 +337,8 @@ static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, chk_addr_ret = inet_addr_type_dev_table(net, dev, v4addr); rcu_read_unlock();
- if (!inet_can_nonlocal_bind(net, inet) && - v4addr != htonl(INADDR_ANY) && - chk_addr_ret != RTN_LOCAL && - chk_addr_ret != RTN_MULTICAST && - chk_addr_ret != RTN_BROADCAST) { + if (!inet_addr_valid_or_nonlocal(net, inet, v4addr, + chk_addr_ret)) { err = -EADDRNOTAVAIL; goto out; } diff --git a/tools/testing/selftests/net/fcnal-test.sh b/tools/testing/selftests/net/fcnal-test.sh index 3313566ce906..7caa4f0e067d 100755 --- a/tools/testing/selftests/net/fcnal-test.sh +++ b/tools/testing/selftests/net/fcnal-test.sh @@ -66,6 +66,10 @@ NSB_LO_IP=172.16.2.2 NSA_LO_IP6=2001:db8:2::1 NSB_LO_IP6=2001:db8:2::2
+# non-local addresses for freebind tests +NL_IP=172.17.1.1 +NL_IP6=2001:db8:4::1 + MD5_PW=abc123 MD5_WRONG_PW=abc1234
@@ -316,6 +320,9 @@ addr2str() ${NSB_LO_IP6}) echo "ns-B loopback IPv6";; ${NSB_LINKIP6}|${NSB_LINKIP6}%*) echo "ns-B IPv6 LLA";;
+ ${NL_IP}) echo "nonlocal IP";; + ${NL_IP6}) echo "nonlocal IPv6";; + ${VRF_IP}) echo "VRF IP";; ${VRF_IP6}) echo "VRF IPv6";;
@@ -1767,6 +1774,14 @@ ipv4_addr_bind_novrf() log_test_addr ${a} $? 0 "Raw socket bind to local address after device bind" done
+ # + # raw socket with nonlocal bind + # + a=${NL_IP} + log_start + run_cmd nettest -s -R -P icmp -f -l ${a} -I ${NSA_DEV} -b + log_test_addr ${a} $? 0 "Raw socket bind to nonlocal address after device bind" + # # tcp sockets # @@ -1815,6 +1830,14 @@ ipv4_addr_bind_vrf() run_cmd nettest -s -R -P icmp -l ${a} -I ${VRF} -b log_test_addr ${a} $? 1 "Raw socket bind to out of scope address after VRF bind"
+ # + # raw socket with nonlocal bind + # + a=${NL_IP} + log_start + run_cmd nettest -s -R -P icmp -f -l ${a} -I ${VRF} -b + log_test_addr ${a} $? 0 "Raw socket bind to nonlocal address after VRF bind" + # # tcp sockets # @@ -1965,6 +1988,7 @@ ipv4_rt()
a=${NSA_IP} log_start + run_cmd nettest ${varg} -s & sleep 1 run_cmd nettest ${varg} -d ${NSA_DEV} -r ${a} & @@ -3402,6 +3426,14 @@ ipv6_addr_bind_novrf() log_test_addr ${a} $? 0 "Raw socket bind to local address after device bind" done
+ # + # raw socket with nonlocal bind + # + a=${NL_IP6} + log_start + run_cmd nettest -6 -s -R -P icmp -f -l ${a} -I ${NSA_DEV} -b + log_test_addr ${a} $? 0 "Raw socket bind to nonlocal address" + # # tcp sockets # @@ -3443,6 +3475,14 @@ ipv6_addr_bind_vrf() run_cmd nettest -6 -s -R -P ipv6-icmp -l ${a} -I ${VRF} -b log_test_addr ${a} $? 1 "Raw socket bind to invalid local address after vrf bind"
+ # + # raw socket with nonlocal bind + # + a=${NL_IP6} + log_start + run_cmd nettest -6 -s -R -P icmp -f -l ${a} -I ${VRF} -b + log_test_addr ${a} $? 0 "Raw socket bind to nonlocal address after VRF bind" + # # tcp sockets # diff --git a/tools/testing/selftests/net/nettest.c b/tools/testing/selftests/net/nettest.c index b599003eb5ba..d9a6fd2cd9d3 100644 --- a/tools/testing/selftests/net/nettest.c +++ b/tools/testing/selftests/net/nettest.c @@ -85,6 +85,7 @@ struct sock_args { int version; /* AF_INET/AF_INET6 */
int use_setsockopt; + int use_freebind; int use_cmsg; const char *dev; const char *server_dev; @@ -514,6 +515,29 @@ static int set_membership(int sd, uint32_t grp, uint32_t addr, int ifindex) return 0; }
+static int set_freebind(int sd, int version) +{ + unsigned int one = 1; + int rc = 0; + + switch (version) { + case AF_INET: + if (setsockopt(sd, SOL_IP, IP_FREEBIND, &one, sizeof(one))) { + log_err_errno("setsockopt(IP_FREEBIND)"); + rc = -1; + } + break; + case AF_INET6: + if (setsockopt(sd, SOL_IPV6, IPV6_FREEBIND, &one, sizeof(one))) { + log_err_errno("setsockopt(IPV6_FREEBIND"); + rc = -1; + } + break; + } + + return rc; +} + static int set_broadcast(int sd) { unsigned int one = 1; @@ -1419,6 +1443,9 @@ static int lsock_init(struct sock_args *args) set_unicast_if(sd, args->ifindex, args->version)) goto err;
+ if (args->use_freebind && set_freebind(sd, args->version)) + goto err; + if (bind_socket(sd, args)) goto err;
@@ -1827,7 +1854,7 @@ static int ipc_parent(int cpid, int fd, struct sock_args *args) return client_status; }
-#define GETOPT_STR "sr:l:c:p:t:g:P:DRn:M:X:m:d:I:BN:O:SCi6xL:0:1:2:3:Fbq" +#define GETOPT_STR "sr:l:c:p:t:g:P:DRn:M:X:m:d:I:BN:O:SCi6xL:0:1:2:3:Fbqf" #define OPT_FORCE_BIND_KEY_IFINDEX 1001 #define OPT_NO_BIND_KEY_IFINDEX 1002
@@ -1864,6 +1891,7 @@ static void print_usage(char *prog) " -I dev bind socket to given device name - server mode\n" " -S use setsockopt (IP_UNICAST_IF or IP_MULTICAST_IF)\n" " to set device binding\n" + " -f bind socket with the IP[V6]_FREEBIND option\n" " -C use cmsg and IP_PKTINFO to specify device binding\n" "\n" " -L len send random message of given length\n" @@ -1999,6 +2027,9 @@ int main(int argc, char *argv[]) case 'S': args.use_setsockopt = 1; break; + case 'f': + args.use_freebind = 1; + break; case 'C': args.use_cmsg = 1; break;