xref: /openbmc/qemu/net/dump.c (revision 64ed6f92) 
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qemu-common.h"
27 #include "clients.h"
28 #include "qapi/error.h"
29 #include "qemu/error-report.h"
30 #include "qemu/iov.h"
31 #include "qemu/log.h"
32 #include "qemu/module.h"
33 #include "qemu/timer.h"
34 #include "qapi/visitor.h"
35 #include "net/filter.h"
36 
37 typedef struct DumpState {
38     int64_t start_ts;
39     int fd;
40     int pcap_caplen;
41 } DumpState;
42 
43 #define PCAP_MAGIC 0xa1b2c3d4
44 
45 struct pcap_file_hdr {
46     uint32_t magic;
47     uint16_t version_major;
48     uint16_t version_minor;
49     int32_t thiszone;
50     uint32_t sigfigs;
51     uint32_t snaplen;
52     uint32_t linktype;
53 };
54 
55 struct pcap_sf_pkthdr {
56     struct {
57         int32_t tv_sec;
58         int32_t tv_usec;
59     } ts;
60     uint32_t caplen;
61     uint32_t len;
62 };
63 
64 static ssize_t dump_receive_iov(DumpState *s, const struct iovec *iov, int cnt)
65 {
66     struct pcap_sf_pkthdr hdr;
67     int64_t ts;
68     int caplen;
69     size_t size = iov_size(iov, cnt);
70     struct iovec dumpiov[cnt + 1];
71 
72     /* Early return in case of previous error. */
73     if (s->fd < 0) {
74         return size;
75     }
76 
77     ts = qemu_clock_get_us(QEMU_CLOCK_VIRTUAL);
78     caplen = size > s->pcap_caplen ? s->pcap_caplen : size;
79 
80     hdr.ts.tv_sec = ts / 1000000 + s->start_ts;
81     hdr.ts.tv_usec = ts % 1000000;
82     hdr.caplen = caplen;
83     hdr.len = size;
84 
85     dumpiov[0].iov_base = &hdr;
86     dumpiov[0].iov_len = sizeof(hdr);
87     cnt = iov_copy(&dumpiov[1], cnt, iov, cnt, 0, caplen);
88 
89     if (writev(s->fd, dumpiov, cnt + 1) != sizeof(hdr) + caplen) {
90         error_report("network dump write error - stopping dump");
91         close(s->fd);
92         s->fd = -1;
93     }
94 
95     return size;
96 }
97 
98 static void dump_cleanup(DumpState *s)
99 {
100     close(s->fd);
101     s->fd = -1;
102 }
103 
104 static int net_dump_state_init(DumpState *s, const char *filename,
105                                int len, Error **errp)
106 {
107     struct pcap_file_hdr hdr;
108     struct tm tm;
109     int fd;
110 
111     fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0644);
112     if (fd < 0) {
113         error_setg_errno(errp, errno, "net dump: can't open %s", filename);
114         return -1;
115     }
116 
117     hdr.magic = PCAP_MAGIC;
118     hdr.version_major = 2;
119     hdr.version_minor = 4;
120     hdr.thiszone = 0;
121     hdr.sigfigs = 0;
122     hdr.snaplen = len;
123     hdr.linktype = 1;
124 
125     if (write(fd, &hdr, sizeof(hdr)) < sizeof(hdr)) {
126         error_setg_errno(errp, errno, "net dump write error");
127         close(fd);
128         return -1;
129     }
130 
131     s->fd = fd;
132     s->pcap_caplen = len;
133 
134     qemu_get_timedate(&tm, 0);
135     s->start_ts = mktime(&tm);
136 
137     return 0;
138 }
139 
140 #define TYPE_FILTER_DUMP "filter-dump"
141 
142 #define FILTER_DUMP(obj) \
143     OBJECT_CHECK(NetFilterDumpState, (obj), TYPE_FILTER_DUMP)
144 
145 struct NetFilterDumpState {
146     NetFilterState nfs;
147     DumpState ds;
148     char *filename;
149     uint32_t maxlen;
150 };
151 typedef struct NetFilterDumpState NetFilterDumpState;
152 
153 static ssize_t filter_dump_receive_iov(NetFilterState *nf, NetClientState *sndr,
154                                        unsigned flags, const struct iovec *iov,
155                                        int iovcnt, NetPacketSent *sent_cb)
156 {
157     NetFilterDumpState *nfds = FILTER_DUMP(nf);
158 
159     dump_receive_iov(&nfds->ds, iov, iovcnt);
160     return 0;
161 }
162 
163 static void filter_dump_cleanup(NetFilterState *nf)
164 {
165     NetFilterDumpState *nfds = FILTER_DUMP(nf);
166 
167     dump_cleanup(&nfds->ds);
168 }
169 
170 static void filter_dump_setup(NetFilterState *nf, Error **errp)
171 {
172     NetFilterDumpState *nfds = FILTER_DUMP(nf);
173 
174     if (!nfds->filename) {
175         error_setg(errp, "dump filter needs 'file' property set!");
176         return;
177     }
178 
179     net_dump_state_init(&nfds->ds, nfds->filename, nfds->maxlen, errp);
180 }
181 
182 static void filter_dump_get_maxlen(Object *obj, Visitor *v, const char *name,
183                                    void *opaque, Error **errp)
184 {
185     NetFilterDumpState *nfds = FILTER_DUMP(obj);
186     uint32_t value = nfds->maxlen;
187 
188     visit_type_uint32(v, name, &value, errp);
189 }
190 
191 static void filter_dump_set_maxlen(Object *obj, Visitor *v, const char *name,
192                                    void *opaque, Error **errp)
193 {
194     NetFilterDumpState *nfds = FILTER_DUMP(obj);
195     uint32_t value;
196 
197     if (!visit_type_uint32(v, name, &value, errp)) {
198         return;
199     }
200     if (value == 0) {
201         error_setg(errp, "Property '%s.%s' doesn't take value '%u'",
202                    object_get_typename(obj), name, value);
203         return;
204     }
205     nfds->maxlen = value;
206 }
207 
208 static char *file_dump_get_filename(Object *obj, Error **errp)
209 {
210     NetFilterDumpState *nfds = FILTER_DUMP(obj);
211 
212     return g_strdup(nfds->filename);
213 }
214 
215 static void file_dump_set_filename(Object *obj, const char *value, Error **errp)
216 {
217    NetFilterDumpState *nfds = FILTER_DUMP(obj);
218 
219     g_free(nfds->filename);
220     nfds->filename = g_strdup(value);
221 }
222 
223 static void filter_dump_instance_init(Object *obj)
224 {
225     NetFilterDumpState *nfds = FILTER_DUMP(obj);
226 
227     nfds->maxlen = 65536;
228 
229     object_property_add(obj, "maxlen", "uint32", filter_dump_get_maxlen,
230                         filter_dump_set_maxlen, NULL, NULL);
231     object_property_add_str(obj, "file", file_dump_get_filename,
232                             file_dump_set_filename);
233 }
234 
235 static void filter_dump_instance_finalize(Object *obj)
236 {
237     NetFilterDumpState *nfds = FILTER_DUMP(obj);
238 
239     g_free(nfds->filename);
240 }
241 
242 static void filter_dump_class_init(ObjectClass *oc, void *data)
243 {
244     NetFilterClass *nfc = NETFILTER_CLASS(oc);
245 
246     nfc->setup = filter_dump_setup;
247     nfc->cleanup = filter_dump_cleanup;
248     nfc->receive_iov = filter_dump_receive_iov;
249 }
250 
251 static const TypeInfo filter_dump_info = {
252     .name = TYPE_FILTER_DUMP,
253     .parent = TYPE_NETFILTER,
254     .class_init = filter_dump_class_init,
255     .instance_init = filter_dump_instance_init,
256     .instance_finalize = filter_dump_instance_finalize,
257     .instance_size = sizeof(NetFilterDumpState),
258 };
259 
260 static void filter_dump_register_types(void)
261 {
262     type_register_static(&filter_dump_info);
263 }
264 
265 type_init(filter_dump_register_types);
266