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 * Copyright (c) 2016-2018 The strace developers.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. The name of the author may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "defs.h"
33 #include "msghdr.h"
34 #include "xstring.h"
35 #include <limits.h>
36
37 static bool
fetch_struct_mmsghdr_for_print(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,void * const mh)38 fetch_struct_mmsghdr_for_print(struct tcb *const tcp,
39 const kernel_ulong_t addr,
40 const unsigned int len, void *const mh)
41 {
42 return (entering(tcp) || !syserror(tcp)) &&
43 fetch_struct_mmsghdr(tcp, addr, mh);
44 }
45
46 struct print_struct_mmsghdr_config {
47 const int *p_user_msg_namelen;
48 unsigned int msg_len_vlen;
49 unsigned int count;
50 bool use_msg_len;
51 };
52
53 static bool
print_struct_mmsghdr(struct tcb * tcp,void * elem_buf,size_t elem_size,void * data)54 print_struct_mmsghdr(struct tcb *tcp, void *elem_buf,
55 size_t elem_size, void *data)
56 {
57 const struct mmsghdr *const mmsg = elem_buf;
58 struct print_struct_mmsghdr_config *const c = data;
59
60 if (!c->count) {
61 tprints("...");
62 return false;
63 }
64 --c->count;
65
66 tprints("{msg_hdr=");
67 print_struct_msghdr(tcp, &mmsg->msg_hdr, c->p_user_msg_namelen,
68 c->use_msg_len ? mmsg->msg_len : (kernel_ulong_t) -1);
69 if (c->msg_len_vlen) {
70 tprintf(", msg_len=%u", mmsg->msg_len);
71 --c->msg_len_vlen;
72 }
73 tprints("}");
74
75 if (c->p_user_msg_namelen)
76 ++c->p_user_msg_namelen;
77
78 return true;
79 }
80
81 static void
free_mmsgvec_data(void * ptr)82 free_mmsgvec_data(void *ptr)
83 {
84 char **pstr = ptr;
85 free(*pstr);
86 *pstr = 0;
87
88 free(ptr);
89 }
90
91 struct mmsgvec_data {
92 char *timeout;
93 unsigned int count;
94 int namelen[IOV_MAX];
95 };
96
97 static void
save_mmsgvec_namelen(struct tcb * const tcp,kernel_ulong_t addr,unsigned int len,const char * const timeout)98 save_mmsgvec_namelen(struct tcb *const tcp, kernel_ulong_t addr,
99 unsigned int len, const char *const timeout)
100 {
101 if (len > IOV_MAX)
102 len = IOV_MAX;
103
104 const size_t data_size = offsetof(struct mmsgvec_data, namelen)
105 + sizeof(int) * len;
106 struct mmsgvec_data *const data = xmalloc(data_size);
107 data->timeout = xstrdup(timeout);
108
109 unsigned int i, fetched;
110
111 for (i = 0; i < len; ++i, addr += fetched) {
112 struct mmsghdr mh;
113
114 fetched = fetch_struct_mmsghdr(tcp, addr, &mh);
115 if (!fetched)
116 break;
117 data->namelen[i] = mh.msg_hdr.msg_namelen;
118 }
119 data->count = i;
120
121 set_tcb_priv_data(tcp, data, free_mmsgvec_data);
122 }
123
124 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)125 decode_mmsgvec(struct tcb *const tcp, const kernel_ulong_t addr,
126 const unsigned int vlen, const unsigned int msg_len_vlen,
127 const bool use_msg_len)
128 {
129 struct mmsghdr mmsg;
130 struct print_struct_mmsghdr_config c = {
131 .msg_len_vlen = msg_len_vlen,
132 .count = IOV_MAX,
133 .use_msg_len = use_msg_len
134 };
135 const struct mmsgvec_data *const data = get_tcb_priv_data(tcp);
136
137 if (data) {
138 if (data->count < c.count)
139 c.count = data->count;
140 c.p_user_msg_namelen = data->namelen;
141 }
142
143 print_array(tcp, addr, vlen, &mmsg, sizeof_struct_mmsghdr(),
144 fetch_struct_mmsghdr_for_print,
145 print_struct_mmsghdr, &c);
146 }
147
148 void
dumpiov_in_mmsghdr(struct tcb * const tcp,kernel_ulong_t addr)149 dumpiov_in_mmsghdr(struct tcb *const tcp, kernel_ulong_t addr)
150 {
151 unsigned int len = tcp->u_rval;
152 unsigned int i, fetched;
153 struct mmsghdr mmsg;
154
155 for (i = 0; i < len; ++i, addr += fetched) {
156 fetched = fetch_struct_mmsghdr(tcp, addr, &mmsg);
157 if (!fetched)
158 break;
159 tprintf(" = %" PRI_klu " buffers in vector %u\n",
160 (kernel_ulong_t) mmsg.msg_hdr.msg_iovlen, i);
161 dumpiov_upto(tcp, mmsg.msg_hdr.msg_iovlen,
162 ptr_to_kulong(mmsg.msg_hdr.msg_iov),
163 mmsg.msg_len);
164 }
165 }
166
SYS_FUNC(sendmmsg)167 SYS_FUNC(sendmmsg)
168 {
169 if (entering(tcp)) {
170 /* sockfd */
171 printfd(tcp, tcp->u_arg[0]);
172 tprints(", ");
173 if (!verbose(tcp)) {
174 /* msgvec */
175 printaddr(tcp->u_arg[1]);
176 /* vlen */
177 tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
178 /* flags */
179 printflags(msg_flags, tcp->u_arg[3], "MSG_???");
180 return RVAL_DECODED;
181 }
182 } else {
183 const unsigned int msg_len_vlen =
184 syserror(tcp) ? 0 : tcp->u_rval;
185 /* msgvec */
186 temporarily_clear_syserror(tcp);
187 decode_mmsgvec(tcp, tcp->u_arg[1], tcp->u_arg[2],
188 msg_len_vlen, false);
189 restore_cleared_syserror(tcp);
190 /* vlen */
191 tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
192 /* flags */
193 printflags(msg_flags, tcp->u_arg[3], "MSG_???");
194 }
195 return 0;
196 }
197
SYS_FUNC(recvmmsg)198 SYS_FUNC(recvmmsg)
199 {
200 if (entering(tcp)) {
201 printfd(tcp, tcp->u_arg[0]);
202 tprints(", ");
203 if (verbose(tcp)) {
204 save_mmsgvec_namelen(tcp, tcp->u_arg[1], tcp->u_arg[2],
205 sprint_timespec(tcp, tcp->u_arg[4]));
206 } else {
207 /* msgvec */
208 printaddr(tcp->u_arg[1]);
209 /* vlen */
210 tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
211 /* flags */
212 printflags(msg_flags, tcp->u_arg[3], "MSG_???");
213 tprints(", ");
214 print_timespec(tcp, tcp->u_arg[4]);
215 }
216 return 0;
217 } else {
218 if (verbose(tcp)) {
219 /* msgvec */
220 decode_mmsgvec(tcp, tcp->u_arg[1], tcp->u_rval,
221 tcp->u_rval, true);
222 /* vlen */
223 tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
224 /* flags */
225 printflags(msg_flags, tcp->u_arg[3], "MSG_???");
226 tprints(", ");
227 /* timeout on entrance */
228 tprints(*(const char **) get_tcb_priv_data(tcp));
229 }
230 if (syserror(tcp))
231 return 0;
232 if (tcp->u_rval == 0) {
233 tcp->auxstr = "Timeout";
234 return RVAL_STR;
235 }
236 if (!verbose(tcp) || !tcp->u_arg[4])
237 return 0;
238 /* timeout on exit */
239 static char str[sizeof("left") + TIMESPEC_TEXT_BUFSIZE];
240 xsprintf(str, "left %s", sprint_timespec(tcp, tcp->u_arg[4]));
241 tcp->auxstr = str;
242 return RVAL_STR;
243 }
244 }
245