tests: check ioctl(SIOCGIFCONF) decoding

* tests/ioctl_sock_gifconf.c: New file.
* tests/ioctl_sock_gifconf.test: New test.
* tests/.gitignore: Add ioctl_sock_gifconf.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(DECODER_TESTS): Add ioctl_sock_gifconf.test.

tests/.gitignore

@@ -121,6 +121,7 @@ ioctl_evdev-v
 ioctl_mtd
 ioctl_rtc
 ioctl_rtc-v
+ioctl_sock_gifconf
 ioctl_uffdio
 ioctl_v4l2
 ioperm

tests/Makefile.am

@@ -182,6 +182,7 @@ check_PROGRAMS = \
 	ioctl_mtd \
 	ioctl_rtc \
 	ioctl_rtc-v \
+	ioctl_sock_gifconf \
 	ioctl_uffdio \
 	ioctl_v4l2 \
 	ioperm \
@@ -577,6 +578,7 @@ DECODER_TESTS = \
 	ioctl_mtd.test \
 	ioctl_rtc.test \
 	ioctl_rtc-v.test \
+	ioctl_sock_gifconf.test \
 	ioctl_uffdio.test \
 	ioctl_v4l2.test \
 	ioperm.test \

tests/ioctl_sock_gifconf.c

@@ -0,0 +1,182 @@
+/*
+ * Check decoding of SIOCGIFCONF command of ioctl syscall.
+ *
+ * Copyright (c) 2016 Eugene Syromyatnikov <evgsyr@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "tests.h"
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+
+#define MAX_STRLEN 1
+
+static void
+print_ifc_len(int val)
+{
+	if (val % (int) sizeof(struct ifreq))
+		printf("%d", val);
+	else
+		printf("%d * sizeof(struct ifreq)",
+		       val / (int) sizeof(struct ifreq));
+}
+
+static void
+print_ifconf(struct ifconf *ifc, int in_len, char *in_buf, long rc)
+{
+	if (in_buf) {
+		printf("{ifc_len=");
+		print_ifc_len(in_len);
+
+		if (in_len != ifc->ifc_len) {
+			printf(" => ");
+			print_ifc_len(ifc->ifc_len);
+		}
+	} else {
+		printf("{ifc_len=");
+		print_ifc_len(ifc->ifc_len);
+	}
+
+	printf(", ifc_buf=");
+
+	if ((rc < 0) || !in_buf) {
+		if (in_buf)
+			printf("%p", in_buf);
+		else
+			printf("NULL");
+	} else {
+		int i;
+
+		printf("[");
+		for (i = 0; i < (ifc->ifc_len) &&
+		    i < (int) (MAX_STRLEN * sizeof(struct ifreq));
+		    i += sizeof(struct ifreq)) {
+			struct ifreq *ifr = (struct ifreq *) (ifc->ifc_buf + i);
+			struct sockaddr_in *const sa_in =
+				(struct sockaddr_in *) &(ifr->ifr_addr);
+
+			if (i)
+				printf(", ");
+			printf("{ifr_name=\"%s\", ifr_addr={sa_family=AF_INET, "
+			       "sin_port=htons(%u), sin_addr=inet_addr(\"%s\")}"
+			       "}", ifr->ifr_name, ntohs(sa_in->sin_port),
+			       inet_ntoa(sa_in->sin_addr));
+		}
+
+		if ((size_t) (ifc->ifc_len - i) >= sizeof(struct ifreq))
+			printf(", ...");
+
+		printf("]");
+	}
+
+	printf("}");
+}
+
+static void
+gifconf_ioctl(int fd, struct ifconf *ifc, bool ifc_valid)
+{
+	const char * errstr;
+	int in_len;
+	char *in_buf;
+	long rc;
+
+	if (ifc_valid) {
+		in_len = ifc->ifc_len;
+		in_buf = ifc->ifc_buf;
+	}
+
+	rc = ioctl(fd, SIOCGIFCONF, ifc);
+	errstr = sprintrc(rc);
+
+	printf("ioctl(%d, SIOCGIFCONF, ", fd);
+	if (ifc_valid) {
+		print_ifconf(ifc, in_len, in_buf, rc);
+	} else {
+		if (ifc)
+			printf("%p", ifc);
+		else
+			printf("NULL");
+	}
+
+	printf(") = %s\n", errstr);
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct ifreq *ifr = tail_alloc(2 * sizeof(*ifr));
+	struct ifconf *ifc = tail_alloc(sizeof(*ifc));
+
+	struct sockaddr_in addr;
+	int fd;
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+	if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+		perror_msg_and_skip("socket AF_INET");
+
+	gifconf_ioctl(fd, NULL, false);
+	gifconf_ioctl(fd, ifc + 1, false);
+
+	ifc->ifc_len = 3141592653U;
+	ifc->ifc_buf = NULL;
+	gifconf_ioctl(fd, ifc, true);
+
+	ifc->ifc_len = 0;
+	ifc->ifc_buf = (char *) (ifr + 2);
+	gifconf_ioctl(fd, ifc, true);
+
+	ifc->ifc_len = 1;
+	ifc->ifc_buf = (char *) (ifr + 1);
+	gifconf_ioctl(fd, ifc, true);
+
+	ifc->ifc_len = 1 * sizeof(*ifr);
+	ifc->ifc_buf = (char *) (ifr + 1);
+	gifconf_ioctl(fd, ifc, true);
+
+	ifc->ifc_len = 2 * sizeof(*ifr);
+	ifc->ifc_buf = (char *) (ifr + 1);
+	gifconf_ioctl(fd, ifc, true);
+
+	ifc->ifc_len = 2 * sizeof(*ifr) + 2;
+	ifc->ifc_buf = (char *) ifr;
+	gifconf_ioctl(fd, ifc, true);
+
+	ifc->ifc_len = 3 * sizeof(*ifr) + 4;
+	ifc->ifc_buf = (char *) ifr;
+	gifconf_ioctl(fd, ifc, true);
+
+	puts("+++ exited with 0 +++");
+	return 0;
+}

tests/ioctl_sock_gifconf.test

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+# Check decoding of SIOCGIFCONF ioctl.
+
+. "${srcdir=.}/init.sh"
+
+run_prog > /dev/null
+run_strace -a28 -s1 -eioctl $args > "$EXP"
+check_prog grep
+grep -v '^ioctl([012],' < "$LOG" > "$OUT"
+match_diff "$OUT" "$EXP"
+rm -f "$EXP" "$OUT"