xref: /openbmc/qemu/net/dump.c (revision d901eff3)
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 "dump.h"
26 #include "qemu-common.h"
27 #include "qemu-error.h"
28 #include "qemu-log.h"
29 #include "qemu-timer.h"
30 
31 typedef struct DumpState {
32     VLANClientState nc;
33     int64_t start_ts;
34     int fd;
35     int pcap_caplen;
36 } DumpState;
37 
38 #define PCAP_MAGIC 0xa1b2c3d4
39 
40 struct pcap_file_hdr {
41     uint32_t magic;
42     uint16_t version_major;
43     uint16_t version_minor;
44     int32_t thiszone;
45     uint32_t sigfigs;
46     uint32_t snaplen;
47     uint32_t linktype;
48 };
49 
50 struct pcap_sf_pkthdr {
51     struct {
52         int32_t tv_sec;
53         int32_t tv_usec;
54     } ts;
55     uint32_t caplen;
56     uint32_t len;
57 };
58 
59 static ssize_t dump_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
60 {
61     DumpState *s = DO_UPCAST(DumpState, nc, nc);
62     struct pcap_sf_pkthdr hdr;
63     int64_t ts;
64     int caplen;
65 
66     /* Early return in case of previous error. */
67     if (s->fd < 0) {
68         return size;
69     }
70 
71     ts = muldiv64(qemu_get_clock_ns(vm_clock), 1000000, get_ticks_per_sec());
72     caplen = size > s->pcap_caplen ? s->pcap_caplen : size;
73 
74     hdr.ts.tv_sec = ts / 1000000 + s->start_ts;
75     hdr.ts.tv_usec = ts % 1000000;
76     hdr.caplen = caplen;
77     hdr.len = size;
78     if (write(s->fd, &hdr, sizeof(hdr)) != sizeof(hdr) ||
79         write(s->fd, buf, caplen) != caplen) {
80         qemu_log("-net dump write error - stop dump\n");
81         close(s->fd);
82         s->fd = -1;
83     }
84 
85     return size;
86 }
87 
88 static void dump_cleanup(VLANClientState *nc)
89 {
90     DumpState *s = DO_UPCAST(DumpState, nc, nc);
91 
92     close(s->fd);
93 }
94 
95 static NetClientInfo net_dump_info = {
96     .type = NET_CLIENT_OPTIONS_KIND_DUMP,
97     .size = sizeof(DumpState),
98     .receive = dump_receive,
99     .cleanup = dump_cleanup,
100 };
101 
102 static int net_dump_init(VLANState *vlan, const char *device,
103                          const char *name, const char *filename, int len)
104 {
105     struct pcap_file_hdr hdr;
106     VLANClientState *nc;
107     DumpState *s;
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_report("-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_report("-net dump write error: %s", strerror(errno));
127         close(fd);
128         return -1;
129     }
130 
131     nc = qemu_new_net_client(&net_dump_info, vlan, NULL, device, name);
132 
133     snprintf(nc->info_str, sizeof(nc->info_str),
134              "dump to %s (len=%d)", filename, len);
135 
136     s = DO_UPCAST(DumpState, nc, nc);
137 
138     s->fd = fd;
139     s->pcap_caplen = len;
140 
141     qemu_get_timedate(&tm, 0);
142     s->start_ts = mktime(&tm);
143 
144     return 0;
145 }
146 
147 int net_init_dump(const NetClientOptions *opts, const char *name,
148                   VLANState *vlan)
149 {
150     int len;
151     const char *file;
152     char def_file[128];
153     const NetdevDumpOptions *dump;
154 
155     assert(opts->kind == NET_CLIENT_OPTIONS_KIND_DUMP);
156     dump = opts->dump;
157 
158     assert(vlan);
159 
160     if (dump->has_file) {
161         file = dump->file;
162     } else {
163         snprintf(def_file, sizeof(def_file), "qemu-vlan%d.pcap", vlan->id);
164         file = def_file;
165     }
166 
167     if (dump->has_len) {
168         if (dump->len > INT_MAX) {
169             error_report("invalid length: %"PRIu64, dump->len);
170             return -1;
171         }
172         len = dump->len;
173     } else {
174         len = 65536;
175     }
176 
177     return net_dump_init(vlan, "dump", name, file, len);
178 }
179