Commit 0922cb68 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by Jakub Kicinski
Browse files

selftests/net: expand cmsg_ip with MSG_MORE 



UDP send with MSG_MORE takes a slightly different path than the
lockless fast path.

For completeness, add coverage to this case too.

Pass MSG_MORE on the initial sendmsg, then follow up with a zero byte
write to unplug the cork.

Unrelated: also add two missing endlines in usage().

Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250307033620.411611-4-willemdebruijn.kernel@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent a18dfa99

tools/testing/selftests/net/cmsg_ip.sh

+7 −4
Original line number Diff line number Diff line
@@ -50,8 +50,9 @@ check_result() { 
# IPV6_DONTFRAG

for ovr in setsock cmsg both diff; do

    for df in 0 1; do

	for p in u i r; do

	for p in u U i r; do

	    [ $p == "u" ] && prot=UDP

	    [ $p == "U" ] && prot=UDP

	    [ $p == "i" ] && prot=ICMP

	    [ $p == "r" ] && prot=RAW
@@ -81,8 +82,9 @@ test_dscp() { 
    ip $IPVER -netns $NS route add table 300 prohibit any



    for ovr in setsock cmsg both diff; do

	for p in u i r; do

	for p in u U i r; do

	    [ $p == "u" ] && prot=UDP

	    [ $p == "U" ] && prot=UDP

	    [ $p == "i" ] && prot=ICMP

	    [ $p == "r" ] && prot=RAW
@@ -134,8 +136,9 @@ test_ttl_hoplimit() { 
    local -r LIM=4



    for ovr in setsock cmsg both diff; do

	for p in u i r; do

	for p in u U i r; do

	    [ $p == "u" ] && prot=UDP

	    [ $p == "U" ] && prot=UDP

	    [ $p == "i" ] && prot=ICMP

	    [ $p == "r" ] && prot=RAW
@@ -166,7 +169,7 @@ test_ttl_hoplimit -4 $TGT4 ttl 
test_ttl_hoplimit -6 $TGT6 hlim



# IPV6 exthdr

for p in u i r; do

for p in u U i r; do

    # Very basic "does it crash" test

    for h in h d r; do

	$NSEXE ./cmsg_sender -p $p -6 -H $h $TGT6 1234

tools/testing/selftests/net/cmsg_sender.c

+19 −5
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ enum { 
	ERN_RECVERR,

	ERN_CMSG_RD,

	ERN_CMSG_RCV,

	ERN_SEND_MORE,

};



struct option_cmsg_u32 {
@@ -46,6 +47,7 @@ struct options { 
	const char *service;

	unsigned int size;

	unsigned int num_pkt;

	bool msg_more;

	struct {

		unsigned int mark;

		unsigned int dontfrag;
@@ -94,7 +96,8 @@ static void __attribute__((noreturn)) cs_usage(const char *bin) 
	       "\t\t-S      send() size\n"

	       "\t\t-4/-6   Force IPv4 / IPv6 only\n"

	       "\t\t-p prot Socket protocol\n"

	       "\t\t        (u = UDP (default); i = ICMP; r = RAW)\n"

	       "\t\t        (u = UDP (default); i = ICMP; r = RAW;\n"

	       "\t\t         U = UDP with MSG_MORE)\n"

	       "\n"

	       "\t\t-m val  Set SO_MARK with given value\n"

	       "\t\t-M val  Set SO_MARK via setsockopt\n"
@@ -109,8 +112,8 @@ static void __attribute__((noreturn)) cs_usage(const char *bin) 
	       "\t\t-l val  Set TTL/HOPLIMIT via cmsg\n"

	       "\t\t-L val  Set TTL/HOPLIMIT via setsockopt\n"

	       "\t\t-H type Add an IPv6 header option\n"

	       "\t\t        (h = HOP; d = DST; r = RTDST)"

	       "");

	       "\t\t        (h = HOP; d = DST; r = RTDST)\n"

	       "\n");

	exit(ERN_HELP);

}
@@ -133,8 +136,11 @@ static void cs_parse_args(int argc, char *argv[]) 
			opt.sock.family = AF_INET6;

			break;

		case 'p':

			if (*optarg == 'u' || *optarg == 'U') {

			if (*optarg == 'u') {

				opt.sock.proto = IPPROTO_UDP;

			} else if (*optarg == 'U') {

				opt.sock.proto = IPPROTO_UDP;

				opt.msg_more = true;

			} else if (*optarg == 'i' || *optarg == 'I') {

				opt.sock.proto = IPPROTO_ICMP;

			} else if (*optarg == 'r') {
@@ -531,7 +537,7 @@ int main(int argc, char *argv[]) 
	cs_write_cmsg(fd, &msg, cbuf, sizeof(cbuf));



	for (i = 0; i < opt.num_pkt; i++) {

		err = sendmsg(fd, &msg, 0);

		err = sendmsg(fd, &msg, opt.msg_more ? MSG_MORE : 0);

		if (err < 0) {

			if (!opt.silent_send)

				fprintf(stderr, "send failed: %s\n", strerror(errno));
@@ -542,6 +548,14 @@ int main(int argc, char *argv[]) 
			err = ERN_SEND_SHORT;

			goto err_out;

		}

		if (opt.msg_more) {

			err = write(fd, NULL, 0);

			if (err < 0) {

				fprintf(stderr, "send more: %s\n", strerror(errno));

				err = ERN_SEND_MORE;

				goto err_out;

			}

		}

	}

	err = ERN_SUCCESS;