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1 /*
2  * Copyright (c) 2010 Andreas Schwab <schwab@linux-m68k.org>
3  * Copyright (c) 2012-2013 Denys Vlasenko <vda.linux@googlemail.com>
4  * Copyright (c) 2014 Masatake YAMATO <yamato@redhat.com>
5  * Copyright (c) 2010-2016 Dmitry V. Levin <ldv@altlinux.org>
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 "defs.h"
32 #include "msghdr.h"
33 #include <limits.h>
34 
35 static int
fetch_struct_mmsghdr_or_printaddr(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,void * const mh)36 fetch_struct_mmsghdr_or_printaddr(struct tcb *const tcp,
37 				  const kernel_ulong_t addr,
38 				  const unsigned int len, void *const mh)
39 {
40 	if ((entering(tcp) || !syserror(tcp))
41 	    && fetch_struct_mmsghdr(tcp, addr, mh)) {
42 		return 0;
43 	} else {
44 		printaddr(addr);
45 		return -1;
46 	}
47 }
48 
49 struct print_struct_mmsghdr_config {
50 	const int *p_user_msg_namelen;
51 	unsigned int msg_len_vlen;
52 	unsigned int count;
53 	bool use_msg_len;
54 };
55 
56 static bool
print_struct_mmsghdr(struct tcb * tcp,void * elem_buf,size_t elem_size,void * data)57 print_struct_mmsghdr(struct tcb *tcp, void *elem_buf,
58 		     size_t elem_size, void *data)
59 {
60 	const struct mmsghdr *const mmsg = elem_buf;
61 	struct print_struct_mmsghdr_config *const c = data;
62 
63 	if (!c->count) {
64 		tprints("...");
65 		return false;
66 	}
67 	--c->count;
68 
69 	tprints("{msg_hdr=");
70 	print_struct_msghdr(tcp, &mmsg->msg_hdr, c->p_user_msg_namelen,
71 			    c->use_msg_len ? mmsg->msg_len : (kernel_ulong_t) -1);
72 	if (c->msg_len_vlen) {
73 		tprintf(", msg_len=%u", mmsg->msg_len);
74 		--c->msg_len_vlen;
75 	}
76 	tprints("}");
77 
78 	if (c->p_user_msg_namelen)
79 		++c->p_user_msg_namelen;
80 
81 	return true;
82 }
83 
84 static void
free_mmsgvec_data(void * ptr)85 free_mmsgvec_data(void *ptr)
86 {
87 	char **pstr = ptr;
88 	free(*pstr);
89 	*pstr = 0;
90 
91 	free(ptr);
92 }
93 
94 struct mmsgvec_data {
95 	char *timeout;
96 	unsigned int count;
97 	int namelen[IOV_MAX];
98 };
99 
100 static void
save_mmsgvec_namelen(struct tcb * const tcp,kernel_ulong_t addr,unsigned int len,const char * const timeout)101 save_mmsgvec_namelen(struct tcb *const tcp, kernel_ulong_t addr,
102 		     unsigned int len, const char *const timeout)
103 {
104 	if (len > IOV_MAX)
105 		len = IOV_MAX;
106 
107 	const size_t data_size = offsetof(struct mmsgvec_data, namelen)
108 				 + sizeof(int) * len;
109 	struct mmsgvec_data *const data = xmalloc(data_size);
110 	data->timeout = xstrdup(timeout);
111 
112 	unsigned int i, fetched;
113 
114 	for (i = 0; i < len; ++i, addr += fetched) {
115 		struct mmsghdr mh;
116 
117 		fetched = fetch_struct_mmsghdr(tcp, addr, &mh);
118 		if (!fetched)
119 			break;
120 		data->namelen[i] = mh.msg_hdr.msg_namelen;
121 	}
122 	data->count = i;
123 
124 	set_tcb_priv_data(tcp, data, free_mmsgvec_data);
125 }
126 
127 static void
decode_mmsgvec(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int vlen,const unsigned int msg_len_vlen,const bool use_msg_len)128 decode_mmsgvec(struct tcb *const tcp, const kernel_ulong_t addr,
129 	       const unsigned int vlen, const unsigned int msg_len_vlen,
130 	       const bool use_msg_len)
131 {
132 	struct mmsghdr mmsg;
133 	struct print_struct_mmsghdr_config c = {
134 		.msg_len_vlen = msg_len_vlen,
135 		.count = IOV_MAX,
136 		.use_msg_len = use_msg_len
137 	};
138 	const struct mmsgvec_data *const data = get_tcb_priv_data(tcp);
139 
140 	if (data) {
141 		if (data->count < c.count)
142 			c.count = data->count;
143 		c.p_user_msg_namelen = data->namelen;
144 	}
145 
146 	print_array(tcp, addr, vlen, &mmsg, sizeof_struct_mmsghdr(),
147 		    fetch_struct_mmsghdr_or_printaddr,
148 		    print_struct_mmsghdr, &c);
149 }
150 
151 void
dumpiov_in_mmsghdr(struct tcb * const tcp,kernel_ulong_t addr)152 dumpiov_in_mmsghdr(struct tcb *const tcp, kernel_ulong_t addr)
153 {
154 	unsigned int len = tcp->u_rval;
155 	unsigned int i, fetched;
156 	struct mmsghdr mmsg;
157 
158 	for (i = 0; i < len; ++i, addr += fetched) {
159 		fetched = fetch_struct_mmsghdr(tcp, addr, &mmsg);
160 		if (!fetched)
161 			break;
162 		tprintf(" = %" PRI_klu " buffers in vector %u\n",
163 			(kernel_ulong_t) mmsg.msg_hdr.msg_iovlen, i);
164 		dumpiov_upto(tcp, mmsg.msg_hdr.msg_iovlen,
165 			     ptr_to_kulong(mmsg.msg_hdr.msg_iov),
166 			     mmsg.msg_len);
167 	}
168 }
169 
SYS_FUNC(sendmmsg)170 SYS_FUNC(sendmmsg)
171 {
172 	if (entering(tcp)) {
173 		/* sockfd */
174 		printfd(tcp, tcp->u_arg[0]);
175 		tprints(", ");
176 		if (!verbose(tcp)) {
177 			/* msgvec */
178 			printaddr(tcp->u_arg[1]);
179 			/* vlen */
180 			tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
181 			/* flags */
182 			printflags(msg_flags, tcp->u_arg[3], "MSG_???");
183 			return RVAL_DECODED;
184 		}
185 	} else {
186 		const unsigned int msg_len_vlen =
187 			syserror(tcp) ? 0 : tcp->u_rval;
188 		/* msgvec */
189 		temporarily_clear_syserror(tcp);
190 		decode_mmsgvec(tcp, tcp->u_arg[1], tcp->u_arg[2],
191 			       msg_len_vlen, false);
192 		restore_cleared_syserror(tcp);
193 		/* vlen */
194 		tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
195 		/* flags */
196 		printflags(msg_flags, tcp->u_arg[3], "MSG_???");
197 	}
198 	return 0;
199 }
200 
SYS_FUNC(recvmmsg)201 SYS_FUNC(recvmmsg)
202 {
203 	if (entering(tcp)) {
204 		printfd(tcp, tcp->u_arg[0]);
205 		tprints(", ");
206 		if (verbose(tcp)) {
207 			save_mmsgvec_namelen(tcp, tcp->u_arg[1], tcp->u_arg[2],
208 					     sprint_timespec(tcp, tcp->u_arg[4]));
209 		} else {
210 			/* msgvec */
211 			printaddr(tcp->u_arg[1]);
212 			/* vlen */
213 			tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
214 			/* flags */
215 			printflags(msg_flags, tcp->u_arg[3], "MSG_???");
216 			tprints(", ");
217 			print_timespec(tcp, tcp->u_arg[4]);
218 		}
219 		return 0;
220 	} else {
221 		if (verbose(tcp)) {
222 			/* msgvec */
223 			decode_mmsgvec(tcp, tcp->u_arg[1], tcp->u_rval,
224 				       tcp->u_rval, true);
225 			/* vlen */
226 			tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
227 			/* flags */
228 			printflags(msg_flags, tcp->u_arg[3], "MSG_???");
229 			tprints(", ");
230 			/* timeout on entrance */
231 			tprints(*(const char **) get_tcb_priv_data(tcp));
232 		}
233 		if (syserror(tcp))
234 			return 0;
235 		if (tcp->u_rval == 0) {
236 			tcp->auxstr = "Timeout";
237 			return RVAL_STR;
238 		}
239 		if (!verbose(tcp) || !tcp->u_arg[4])
240 			return 0;
241 		/* timeout on exit */
242 		static char str[sizeof("left") + TIMESPEC_TEXT_BUFSIZE];
243 		snprintf(str, sizeof(str), "left %s",
244 			 sprint_timespec(tcp, tcp->u_arg[4]));
245 		tcp->auxstr = str;
246 		return RVAL_STR;
247 	}
248 }
249