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1 /*
2  * Check decoding of SIOCGIFCONF command of ioctl syscall.
3  *
4  * Copyright (c) 2016 Eugene Syromyatnikov <evgsyr@gmail.com>
5  * Copyright (c) 2016-2017 The strace developers.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include "tests.h"
32 
33 #include <stdbool.h>
34 #include <stdio.h>
35 #include <string.h>
36 
37 #include <arpa/inet.h>
38 #include <net/if.h>
39 #include <sys/ioctl.h>
40 #include <sys/socket.h>
41 
42 #define MAX_STRLEN 1
43 
44 static void
print_ifc_len(int val)45 print_ifc_len(int val)
46 {
47 	if (val % (int) sizeof(struct ifreq))
48 		printf("%d", val);
49 	else
50 		printf("%d * sizeof(struct ifreq)",
51 		       val / (int) sizeof(struct ifreq));
52 }
53 
54 static void
print_ifconf(struct ifconf * ifc,int in_len,char * in_buf,long rc)55 print_ifconf(struct ifconf *ifc, int in_len, char *in_buf, long rc)
56 {
57 	if (in_buf) {
58 		printf("{ifc_len=");
59 		print_ifc_len(in_len);
60 
61 		if (in_len != ifc->ifc_len) {
62 			printf(" => ");
63 			print_ifc_len(ifc->ifc_len);
64 		}
65 	} else {
66 		printf("{ifc_len=");
67 		print_ifc_len(ifc->ifc_len);
68 	}
69 
70 	printf(", ifc_buf=");
71 
72 	if ((rc < 0) || !in_buf) {
73 		if (in_buf)
74 			printf("%p", in_buf);
75 		else
76 			printf("NULL");
77 	} else {
78 		int i;
79 
80 		printf("[");
81 		for (i = 0; i < (ifc->ifc_len) &&
82 		    i < (int) (MAX_STRLEN * sizeof(struct ifreq));
83 		    i += sizeof(struct ifreq)) {
84 			struct ifreq *ifr = (struct ifreq *) (ifc->ifc_buf + i);
85 			struct sockaddr_in *const sa_in =
86 				(struct sockaddr_in *) &(ifr->ifr_addr);
87 
88 			if (i)
89 				printf(", ");
90 			printf("{ifr_name=\"%s\", ifr_addr={sa_family=AF_INET, "
91 			       "sin_port=htons(%u), sin_addr=inet_addr(\"%s\")}"
92 			       "}", ifr->ifr_name, ntohs(sa_in->sin_port),
93 			       inet_ntoa(sa_in->sin_addr));
94 		}
95 
96 		if ((size_t) (ifc->ifc_len - i) >= sizeof(struct ifreq))
97 			printf(", ...");
98 
99 		printf("]");
100 	}
101 
102 	printf("}");
103 }
104 
105 static void
gifconf_ioctl(int fd,struct ifconf * ifc,bool ifc_valid)106 gifconf_ioctl(int fd, struct ifconf *ifc, bool ifc_valid)
107 {
108 	const char *errstr;
109 	int in_len;
110 	char *in_buf;
111 	long rc;
112 
113 	if (ifc_valid) {
114 		in_len = ifc->ifc_len;
115 		in_buf = ifc->ifc_buf;
116 	}
117 
118 	rc = ioctl(fd, SIOCGIFCONF, ifc);
119 	errstr = sprintrc(rc);
120 
121 	printf("ioctl(%d, SIOCGIFCONF, ", fd);
122 	if (ifc_valid) {
123 		print_ifconf(ifc, in_len, in_buf, rc);
124 	} else {
125 		if (ifc)
126 			printf("%p", ifc);
127 		else
128 			printf("NULL");
129 	}
130 
131 	printf(") = %s\n", errstr);
132 }
133 
134 int
main(int argc,char * argv[])135 main(int argc, char *argv[])
136 {
137 	struct ifreq *ifr = tail_alloc(2 * sizeof(*ifr));
138 	TAIL_ALLOC_OBJECT_CONST_PTR(struct ifconf, ifc);
139 
140 	struct sockaddr_in addr;
141 	int fd;
142 
143 	memset(&addr, 0, sizeof(addr));
144 	addr.sin_family = AF_INET;
145 	addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
146 
147 	if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
148 		perror_msg_and_skip("socket AF_INET");
149 
150 	gifconf_ioctl(fd, NULL, false);
151 	gifconf_ioctl(fd, ifc + 1, false);
152 
153 	ifc->ifc_len = 3141592653U;
154 	ifc->ifc_buf = NULL;
155 	gifconf_ioctl(fd, ifc, true);
156 
157 	ifc->ifc_len = 0;
158 	ifc->ifc_buf = (char *) (ifr + 2);
159 	gifconf_ioctl(fd, ifc, true);
160 
161 	ifc->ifc_len = 1;
162 	ifc->ifc_buf = (char *) (ifr + 1);
163 	gifconf_ioctl(fd, ifc, true);
164 
165 	ifc->ifc_len = 1 * sizeof(*ifr);
166 	ifc->ifc_buf = (char *) (ifr + 1);
167 	gifconf_ioctl(fd, ifc, true);
168 
169 	ifc->ifc_len = 2 * sizeof(*ifr);
170 	ifc->ifc_buf = (char *) (ifr + 1);
171 	gifconf_ioctl(fd, ifc, true);
172 
173 	ifc->ifc_len = 2 * sizeof(*ifr) + 2;
174 	ifc->ifc_buf = (char *) ifr;
175 	gifconf_ioctl(fd, ifc, true);
176 
177 	ifc->ifc_len = 3 * sizeof(*ifr) + 4;
178 	ifc->ifc_buf = (char *) ifr;
179 	gifconf_ioctl(fd, ifc, true);
180 
181 	puts("+++ exited with 0 +++");
182 	return 0;
183 }
184