tests: fix potential unaligned access in netlink_sock_diag.test

Despite our efforts made to avoid unaligned access, gcc appears to be
generating instructions that might cause unaligned access when copying
structures to unaligned addresses.

Fix this issue by replacing copying of structures to unaligned addresses
with memcpy calls.

* tests/netlink_sock_diag.c (INIT_STRUCT): New macro.
(test_odd_family_req, test_odd_family_msg, test_unix_diag_req,
test_unix_diag_msg, test_netlink_diag_req, test_netlink_diag_msg,
test_packet_diag_req, test_packet_diag_msg, test_inet_diag_sockid,
test_inet_diag_req, test_inet_diag_req_v2, test_inet_diag_msg,
test_smc_diag_req, test_smc_diag_msg): Use it to initialize potentially
unaligned struct nlmsghdr.  Do not access nlh->nlmsg_len.

diff --git a/tests/netlink_sock_diag.c b/tests/netlink_sock_diag.c
index 26e43257b730ec6a90e7273c348e5c0b70dde2bb..f5f2784325ec4228d1ac4cdabd8a3019ff440fa2 100644 (file)
--- a/tests/netlink_sock_diag.c
+++ b/tests/netlink_sock_diag.c
@@ -52,6 +52,11 @@
 #  define NETLINK_SOCK_DIAG NETLINK_INET_DIAG
 # endif
 
+#define INIT_STRUCT(type, name, ...)                   \
+       do {                                            \
+               type tmp = { __VA_ARGS__ };             \
+               memcpy(name, &tmp, sizeof(tmp));        \
+       } while (0)
 static void
 test_nlmsg_type(const int fd)
 {
@@ -97,11 +102,11 @@ test_odd_family_req(const int fd)
        /* unspecified family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        family = NLMSG_DATA(nlh);
        *family = 0;
 
@@ -148,11 +153,11 @@ test_odd_family_req(const int fd)
        /* unspecified family and string */
        nlh = nlh0 - (sizeof(*family) + 4);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        family = NLMSG_DATA(nlh);
        *family = 0;
        memcpy(family + 1, "1234", 4);
@@ -194,11 +199,11 @@ test_odd_family_msg(const int fd)
        /* unspecified family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        family = NLMSG_DATA(nlh);
        *family = 0;
 
@@ -245,11 +250,11 @@ test_odd_family_msg(const int fd)
        /* unspecified family and string */
        nlh = nlh0 - (sizeof(*family) + 4);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        family = NLMSG_DATA(nlh);
        *family = 0;
        memcpy(family + 1, "1234", 4);
@@ -292,11 +297,11 @@ test_unix_diag_req(const int fd)
        /* family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_UNIX;
 
@@ -313,11 +318,11 @@ test_unix_diag_req(const int fd)
        /* family and string */
        nlh = nlh0 - (sizeof(*family) + 4);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_UNIX;
        memcpy(family + 1, "1234", 4);
@@ -335,11 +340,11 @@ test_unix_diag_req(const int fd)
 
        /* unix_diag_req */
        nlh = nlh0 - sizeof(*req);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*req),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        req = NLMSG_DATA(nlh);
        *req = (struct unix_diag_req) {
                .sdiag_family = AF_UNIX,
@@ -350,7 +355,8 @@ test_unix_diag_req(const int fd)
                .udiag_cookie = { 0xdeadbeef, 0xbadc0ded }
        };
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*req), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_REQUEST, seq=0, pid=0}"
@@ -358,9 +364,10 @@ test_unix_diag_req(const int fd)
               ", udiag_states=1<<TCP_ESTABLISHED|1<<TCP_LISTEN, udiag_ino=%u"
               ", udiag_show=UDIAG_SHOW_NAME, udiag_cookie=[%u, %u]}}"
               ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len,
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*req),
               253, 0xfacefeed, 0xdeadbeef, 0xbadc0ded,
-              nlh->nlmsg_len, sprintrc(rc));
+              NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              sprintrc(rc));
 
        /* short read of unix_diag_req */
        nlh = nlh0 - (sizeof(*req) - 1);
@@ -391,11 +398,11 @@ test_unix_diag_msg(const int fd)
        /* family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_UNIX;
 
@@ -412,11 +419,11 @@ test_unix_diag_msg(const int fd)
        /* family and string */
        nlh = nlh0 - (sizeof(*family) + 4);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_UNIX;
        memcpy(family + 1, "1234", 4);
@@ -434,11 +441,11 @@ test_unix_diag_msg(const int fd)
 
        /* unix_diag_msg */
        nlh = nlh0 - sizeof(*msg);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*msg),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        msg = NLMSG_DATA(nlh);
        *msg = (struct unix_diag_msg) {
                .udiag_family = AF_UNIX,
@@ -448,7 +455,8 @@ test_unix_diag_msg(const int fd)
                .udiag_cookie = { 0xdeadbeef, 0xbadc0ded }
        };
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*msg), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_DUMP, seq=0, pid=0}"
@@ -456,9 +464,10 @@ test_unix_diag_msg(const int fd)
               ", udiag_state=TCP_FIN_WAIT1"
               ", udiag_ino=%u, udiag_cookie=[%u, %u]}}"
               ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len,
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*msg),
               0xfacefeed, 0xdeadbeef, 0xbadc0ded,
-              nlh->nlmsg_len, sprintrc(rc));
+              NLMSG_HDRLEN + (unsigned int) sizeof(*msg),
+              sprintrc(rc));
 
        /* short read of unix_diag_msg */
        nlh = nlh0 - (sizeof(*msg) - 1);
@@ -489,11 +498,11 @@ test_netlink_diag_req(const int fd)
        /* family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_NETLINK;
 
@@ -510,11 +519,11 @@ test_netlink_diag_req(const int fd)
        /* family and string */
        nlh = nlh0 - (sizeof(*family) + 4);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_NETLINK;
        memcpy(family + 1, "1234", 4);
@@ -532,11 +541,11 @@ test_netlink_diag_req(const int fd)
 
        /* netlink_diag_req */
        nlh = nlh0 - sizeof(*req);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*req),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        req = NLMSG_DATA(nlh);
        *req = (struct netlink_diag_req) {
                .sdiag_family = AF_NETLINK,
@@ -547,27 +556,33 @@ test_netlink_diag_req(const int fd)
        };
 
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*req), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_REQUEST, seq=0, pid=0}"
               ", {sdiag_family=AF_NETLINK, sdiag_protocol=NDIAG_PROTO_ALL"
               ", ndiag_ino=%u, ndiag_show=NDIAG_SHOW_MEMINFO"
               ", ndiag_cookie=[%u, %u]}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, 0xfacefeed, 0xdeadbeef,
-              0xbadc0ded, nlh->nlmsg_len, sprintrc(rc));
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              0xfacefeed, 0xdeadbeef, 0xbadc0ded,
+              NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              sprintrc(rc));
 
        req->sdiag_protocol = NETLINK_ROUTE;
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*req), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_REQUEST, seq=0, pid=0}"
               ", {sdiag_family=AF_NETLINK, sdiag_protocol=NETLINK_ROUTE"
               ", ndiag_ino=%u, ndiag_show=NDIAG_SHOW_MEMINFO"
               ", ndiag_cookie=[%u, %u]}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, 0xfacefeed, 0xdeadbeef,
-              0xbadc0ded, nlh->nlmsg_len, sprintrc(rc));
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              0xfacefeed, 0xdeadbeef, 0xbadc0ded,
+              NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              sprintrc(rc));
 
        /* short read of netlink_diag_req */
        nlh = nlh0 - (sizeof(*req) - 1);
@@ -599,11 +614,11 @@ test_netlink_diag_msg(const int fd)
        /* family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_NETLINK;
 
@@ -620,11 +635,11 @@ test_netlink_diag_msg(const int fd)
        /* family and string */
        nlh = nlh0 - (sizeof(*family) + 4);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_NETLINK;
        memcpy(family + 1, "1234", 4);
@@ -642,11 +657,11 @@ test_netlink_diag_msg(const int fd)
 
        /* netlink_diag_msg */
        nlh = nlh0 - sizeof(*msg);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*msg),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        msg = NLMSG_DATA(nlh);
        *msg = (struct netlink_diag_msg) {
                .ndiag_family = AF_NETLINK,
@@ -660,7 +675,8 @@ test_netlink_diag_msg(const int fd)
                .ndiag_cookie = { 0xbadc0ded, 0xdeadbeef }
        };
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*msg), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_DUMP, seq=0, pid=0}, {ndiag_family=AF_NETLINK"
@@ -668,9 +684,11 @@ test_netlink_diag_msg(const int fd)
               ", ndiag_state=NETLINK_CONNECTED, ndiag_portid=%u"
               ", ndiag_dst_portid=%u, ndiag_dst_group=%u, ndiag_ino=%u"
               ", ndiag_cookie=[%u, %u]}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, 0xbadc0ded, 0xdeadbeef, 0xfacefeed,
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*msg),
+              0xbadc0ded, 0xdeadbeef, 0xfacefeed,
               0xdaeefacd, 0xbadc0ded, 0xdeadbeef,
-              nlh->nlmsg_len, sprintrc(rc));
+              NLMSG_HDRLEN + (unsigned int) sizeof(*msg),
+              sprintrc(rc));
 
        /* short read of netlink_diag_msg */
        nlh = nlh0 - (sizeof(*msg) - 1);
@@ -701,11 +719,11 @@ test_packet_diag_req(const int fd)
 
        /* family only */
        nlh = nlh0 - sizeof(*family);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_PACKET;
 
@@ -721,11 +739,11 @@ test_packet_diag_req(const int fd)
 
        /* family and string */
        nlh = nlh0 - (sizeof(*family) + 4);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_PACKET;
        memcpy(family + 1, "1234", 4);
@@ -743,11 +761,11 @@ test_packet_diag_req(const int fd)
 
        /* packet_diag_req */
        nlh = nlh0 - sizeof(*req);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*req),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
        req = NLMSG_DATA(nlh);
        *req = (struct packet_diag_req) {
                .sdiag_family = AF_PACKET,
@@ -757,7 +775,8 @@ test_packet_diag_req(const int fd)
                .pdiag_cookie = { 0xdeadbeef, 0xbadc0ded }
        };
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*req), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_REQUEST, seq=0, pid=0}"
@@ -765,8 +784,10 @@ test_packet_diag_req(const int fd)
               ", pdiag_ino=%u, pdiag_show=PACKET_SHOW_INFO"
               ", pdiag_cookie=[%u, %u]}}, %u"
               ", MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, 0xfacefeed, 0xdeadbeef, 0xbadc0ded,
-              nlh->nlmsg_len, sprintrc(rc));
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              0xfacefeed, 0xdeadbeef, 0xbadc0ded,
+              NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              sprintrc(rc));
 
        /* short read of packet_diag_req */
        nlh = nlh0 - (sizeof(*req) - 1);
@@ -796,11 +817,11 @@ test_packet_diag_msg(const int fd)
 
        /* family only */
        nlh = nlh0 - sizeof(*family);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_PACKET;
 
@@ -816,11 +837,11 @@ test_packet_diag_msg(const int fd)
 
        /* family and string */
        nlh = nlh0 - (sizeof(*family) + 4);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        family = NLMSG_DATA(nlh);
        *family = AF_PACKET;
        memcpy(family + 1, "1234", 4);
@@ -838,11 +859,11 @@ test_packet_diag_msg(const int fd)
 
        /* packet_diag_msg */
        nlh = nlh0 - sizeof(*msg);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*msg),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
        msg = NLMSG_DATA(nlh);
        *msg = (struct packet_diag_msg) {
                .pdiag_family = AF_PACKET,
@@ -852,15 +873,18 @@ test_packet_diag_msg(const int fd)
                .pdiag_cookie = { 0xdeadbeef, 0xbadc0ded }
        };
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*msg), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_DUMP, seq=0, pid=0}"
               ", {pdiag_family=AF_PACKET, pdiag_type=SOCK_STREAM"
               ", pdiag_num=%u, pdiag_ino=%u, pdiag_cookie=[%u, %u]}}"
               ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, 0xbadc, 0xfacefeed,
-              0xdeadbeef, 0xbadc0ded, nlh->nlmsg_len, sprintrc(rc));
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*msg),
+              0xbadc, 0xfacefeed, 0xdeadbeef, 0xbadc0ded,
+              NLMSG_HDRLEN + (unsigned int) sizeof(*msg),
+              sprintrc(rc));
 
        /* short read of packet_diag_msg */
        nlh = nlh0 - (sizeof(*msg) - 1);
@@ -891,11 +915,11 @@ test_inet_diag_sockid(const int fd)
 
        nlh = nlh0 - sizeof(*req);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*req),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
 
        req = NLMSG_DATA(nlh);
        *req = (struct inet_diag_req_v2) {
@@ -916,7 +940,8 @@ test_inet_diag_sockid(const int fd)
        if (!inet_pton(AF_INET, address, &req->id.idiag_dst))
                perror_msg_and_skip("sendto");
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*req), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_REQUEST, seq=0, pid=0}"
@@ -926,9 +951,11 @@ test_inet_diag_sockid(const int fd)
               ", idiag_dport=htons(%u), inet_pton(AF_INET, \"%s\", &idiag_src)"
               ", inet_pton(AF_INET, \"%s\", &idiag_dst), idiag_if=%u"
               ", idiag_cookie=[%u, %u]}}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, ntohs(0xfacd), ntohs(0xdead),
-              address, address, 0xadcdfafc, 0xdeadbeef,
-              0xbadc0ded, nlh->nlmsg_len, sprintrc(rc));
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              ntohs(0xfacd), ntohs(0xdead), address, address,
+              0xadcdfafc, 0xdeadbeef, 0xbadc0ded,
+              NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              sprintrc(rc));
 
        req->sdiag_family = AF_INET6;
        if (!inet_pton(AF_INET6, address6, &req->id.idiag_src))
@@ -936,7 +963,8 @@ test_inet_diag_sockid(const int fd)
        if (!inet_pton(AF_INET6, address6, &req->id.idiag_dst))
                perror_msg_and_skip("sendto");
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*req), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_REQUEST, seq=0, pid=0}"
@@ -946,9 +974,11 @@ test_inet_diag_sockid(const int fd)
               ", idiag_dport=htons(%u), inet_pton(AF_INET6, \"%s\", &idiag_src)"
               ", inet_pton(AF_INET6, \"%s\", &idiag_dst), idiag_if=%u"
               ", idiag_cookie=[%u, %u]}}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, ntohs(0xfacd), ntohs(0xdead),
-              address6, address6, 0xadcdfafc, 0xdeadbeef,
-              0xbadc0ded, nlh->nlmsg_len, sprintrc(rc));
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              ntohs(0xfacd), ntohs(0xdead), address6, address6,
+              0xadcdfafc, 0xdeadbeef, 0xbadc0ded,
+              NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              sprintrc(rc));
 }
 
 static void
@@ -964,11 +994,11 @@ test_inet_diag_req(const int fd)
        /* family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = TCPDIAG_GETSOCK,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
 
        family = NLMSG_DATA(nlh);
        *family = AF_INET;
@@ -986,11 +1016,11 @@ test_inet_diag_req(const int fd)
        /* family and string */
        nlh = nlh0 - (sizeof(*family) + 4);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = TCPDIAG_GETSOCK,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
 
        family = NLMSG_DATA(nlh);
        *family = AF_INET;
@@ -1009,11 +1039,11 @@ test_inet_diag_req(const int fd)
 
        /* inet_diag_req */
        nlh = nlh0 - sizeof(*req);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*req),
                .nlmsg_type = TCPDIAG_GETSOCK,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
 
        req = NLMSG_DATA(nlh);
        *req = (struct inet_diag_req) {
@@ -1036,7 +1066,8 @@ test_inet_diag_req(const int fd)
        if (!inet_pton(AF_INET, address, &req->id.idiag_dst))
                perror_msg_and_skip("sendto");
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*req), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=TCPDIAG_GETSOCK"
               ", flags=NLM_F_REQUEST, seq=0, pid=0}"
@@ -1048,10 +1079,11 @@ test_inet_diag_req(const int fd)
               ", idiag_if=%u, idiag_cookie=[%u, %u]}"
               ", idiag_states=1<<TCP_LAST_ACK, idiag_dbs=%u}}"
               ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, 0xde, 0xba, ntohs(0xdead),
-              ntohs(0xadcd), address, address, 0xadcdfafc,
-              0xdeadbeef, 0xbadc0ded, 0xfacefeed,
-              nlh->nlmsg_len, sprintrc(rc));
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              0xde, 0xba, ntohs(0xdead), ntohs(0xadcd), address, address,
+              0xadcdfafc, 0xdeadbeef, 0xbadc0ded, 0xfacefeed,
+              NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              sprintrc(rc));
 
        /* short read of inet_diag_req */
        nlh = nlh0 - (sizeof(*req) - 1);
@@ -1084,11 +1116,11 @@ test_inet_diag_req_v2(const int fd)
        /* family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
 
        family = NLMSG_DATA(nlh);
        *family = AF_INET;
@@ -1105,11 +1137,11 @@ test_inet_diag_req_v2(const int fd)
 
        /* family and string */
        nlh = nlh0 - sizeof(*family) - 4;
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
 
        family = NLMSG_DATA(nlh);
        *family = AF_INET;
@@ -1129,11 +1161,11 @@ test_inet_diag_req_v2(const int fd)
        /* inet_diag_req_v2 */
        nlh = nlh0 - sizeof(*req);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*req),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
 
        req = NLMSG_DATA(nlh);
        *req = (struct inet_diag_req_v2) {
@@ -1154,7 +1186,8 @@ test_inet_diag_req_v2(const int fd)
        if (!inet_pton(AF_INET, address, &req->id.idiag_dst))
                perror_msg_and_skip("sendto");
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*req), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_REQUEST, seq=0, pid=0}"
@@ -1164,9 +1197,11 @@ test_inet_diag_req_v2(const int fd)
               ", idiag_dport=htons(%u), inet_pton(AF_INET, \"%s\", &idiag_src)"
               ", inet_pton(AF_INET, \"%s\", &idiag_dst), idiag_if=%u"
               ", idiag_cookie=[%u, %u]}}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, ntohs(0xfacd), ntohs(0xdead),
-              address, address, 0xadcdfafc, 0xdeadbeef,
-              0xbadc0ded, nlh->nlmsg_len, sprintrc(rc));
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              ntohs(0xfacd), ntohs(0xdead), address, address,
+              0xadcdfafc, 0xdeadbeef, 0xbadc0ded,
+              NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              sprintrc(rc));
 
        /* short read of inet_diag_req_v2 */
        nlh = nlh0 - (sizeof(*req) - 1);
@@ -1198,11 +1233,11 @@ test_inet_diag_msg(const int fd)
        /* family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
 
        family = NLMSG_DATA(nlh);
        *family = AF_INET;
@@ -1220,11 +1255,11 @@ test_inet_diag_msg(const int fd)
        /* family and string */
        nlh = nlh0 - sizeof(*family) - 4;
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
 
        family = NLMSG_DATA(nlh);
        *family = AF_INET;
@@ -1243,11 +1278,11 @@ test_inet_diag_msg(const int fd)
 
        /* inet_diag_msg */
        nlh = nlh0 - sizeof(*msg);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*msg),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
 
        msg = NLMSG_DATA(nlh);
        *msg = (struct inet_diag_msg) {
@@ -1273,7 +1308,8 @@ test_inet_diag_msg(const int fd)
        if (!inet_pton(AF_INET, address, &msg->id.idiag_dst))
                perror_msg_and_skip("sendto");
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*msg), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_DUMP, seq=0, pid=0}"
@@ -1286,10 +1322,12 @@ test_inet_diag_msg(const int fd)
               ", idiag_expires=%u, idiag_rqueue=%u, idiag_wqueue=%u"
               ", idiag_uid=%u, idiag_inode=%u}}"
               ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, 0xfa, 0xde, ntohs(0xfacf), ntohs(0xdead),
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*msg),
+              0xfa, 0xde, ntohs(0xfacf), ntohs(0xdead),
               address, address, 0xadcdfafc, 0xdeadbeef, 0xbadc0ded,
               0xfacefeed, 0xdeadbeef, 0xadcdfafc, 0xdecefaeb, 0xbadc0ded,
-              nlh->nlmsg_len, sprintrc(rc));
+              NLMSG_HDRLEN + (unsigned int) sizeof(*msg),
+              sprintrc(rc));
 
        /* short read of inet_diag_msg */
        nlh = nlh0 - (sizeof(*msg) - 1);
@@ -1322,11 +1360,11 @@ test_smc_diag_req(const int fd)
        /* family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
 
        family = NLMSG_DATA(nlh);
        *family = AF_SMC;
@@ -1344,11 +1382,11 @@ test_smc_diag_req(const int fd)
        /* family and string */
        nlh = nlh0 - sizeof(*family) - 4;
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
 
        family = NLMSG_DATA(nlh);
        *family = AF_SMC;
@@ -1367,11 +1405,11 @@ test_smc_diag_req(const int fd)
 
        /* smc_diag_req */
        nlh = nlh0 - sizeof(*req);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*req),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_REQUEST,
-       };
+               .nlmsg_flags = NLM_F_REQUEST
+       );
 
        req = NLMSG_DATA(nlh);
        *req = (struct smc_diag_req) {
@@ -1390,7 +1428,8 @@ test_smc_diag_req(const int fd)
        if (!inet_pton(AF_INET, address, &req->id.idiag_dst))
                perror_msg_and_skip("sendto");
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*req), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_REQUEST, seq=0, pid=0}, {diag_family=AF_SMC"
@@ -1400,9 +1439,11 @@ test_smc_diag_req(const int fd)
               ", inet_pton(AF_INET, \"%s\", &idiag_dst)"
               ", idiag_if=%u, idiag_cookie=[%u, %u]}}}"
               ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, htons(0xdead), htons(0xadcd),
-              address, address, 0xadcdfafc, 0xdeadbeef, 0xbadc0ded,
-              nlh->nlmsg_len, sprintrc(rc));
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              htons(0xdead), htons(0xadcd), address, address,
+              0xadcdfafc, 0xdeadbeef, 0xbadc0ded,
+              NLMSG_HDRLEN + (unsigned int) sizeof(*req),
+              sprintrc(rc));
 
        /* short read of smc_diag_req */
        nlh = nlh0 - (sizeof(*req) - 1);
@@ -1434,11 +1475,11 @@ test_smc_diag_msg(const int fd)
        /* family only */
        nlh = nlh0 - sizeof(*family);
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
 
        family = NLMSG_DATA(nlh);
        *family = AF_SMC;
@@ -1456,11 +1497,11 @@ test_smc_diag_msg(const int fd)
        /* family and string */
        nlh = nlh0 - sizeof(*family) - 4;
        /* beware of unaligned access to nlh members */
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*family) + 4,
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
 
        family = NLMSG_DATA(nlh);
        *family = AF_SMC;
@@ -1479,11 +1520,11 @@ test_smc_diag_msg(const int fd)
 
        /* smc_diag_msg */
        nlh = nlh0 - sizeof(*msg);
-       *nlh = (struct nlmsghdr) {
+       INIT_STRUCT(struct nlmsghdr, nlh,
                .nlmsg_len = NLMSG_HDRLEN + sizeof(*msg),
                .nlmsg_type = SOCK_DIAG_BY_FAMILY,
-               .nlmsg_flags = NLM_F_DUMP,
-       };
+               .nlmsg_flags = NLM_F_DUMP
+       );
 
        msg = NLMSG_DATA(nlh);
        *msg = (struct smc_diag_msg) {
@@ -1506,7 +1547,8 @@ test_smc_diag_msg(const int fd)
        if (!inet_pton(AF_INET, address, &msg->id.idiag_dst))
                perror_msg_and_skip("sendto");
 
-       rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
+       rc = sendto(fd, nlh, NLMSG_HDRLEN + sizeof(*msg), MSG_DONTWAIT,
+                   NULL, 0);
 
        printf("sendto(%d, {{len=%u, type=SOCK_DIAG_BY_FAMILY"
               ", flags=NLM_F_DUMP, seq=0, pid=0}, {diag_family=AF_SMC"
@@ -1517,10 +1559,11 @@ test_smc_diag_msg(const int fd)
               ", idiag_if=%u, idiag_cookie=[%u, %u]}"
               ", diag_uid=%u, diag_inode=%u}}, %u"
               ", MSG_DONTWAIT, NULL, 0) = %s\n",
-              fd, nlh->nlmsg_len, 0xde, 0xba,
-              htons(0xdead), htons(0xadcd), address, address,
+              fd, NLMSG_HDRLEN + (unsigned int) sizeof(*msg),
+              0xde, 0xba, htons(0xdead), htons(0xadcd), address, address,
               0xadcdfafc, 0xdeadbeef, 0xbadc0ded, 0xadcdfafc, 0xbadc0ded,
-              nlh->nlmsg_len, sprintrc(rc));
+              NLMSG_HDRLEN + (unsigned int) sizeof(*msg),
+              sprintrc(rc));
 
        /* short read of smc_diag_msg */
        nlh = nlh0 - (sizeof(*msg) - 1);