net/dump.c

   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 "sysemu.h"
  28 #include "qemu-error.h"
  29 #include "qemu-log.h"
  30
  31 typedef struct DumpState {
  32     VLANClientState nc;
  33     int fd;
  34     int pcap_caplen;
  35 } DumpState;
  36
  37 #define PCAP_MAGIC 0xa1b2c3d4
  38
  39 struct pcap_file_hdr {
  40     uint32_t magic;
  41     uint16_t version_major;
  42     uint16_t version_minor;
  43     int32_t thiszone;
  44     uint32_t sigfigs;
  45     uint32_t snaplen;
  46     uint32_t linktype;
  47 };
  48
  49 struct pcap_sf_pkthdr {
  50     struct {
  51         int32_t tv_sec;
  52         int32_t tv_usec;
  53     } ts;
  54     uint32_t caplen;
  55     uint32_t len;
  56 };
  57
  58 static ssize_t dump_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
  59 {
  60     DumpState *s = DO_UPCAST(DumpState, nc, nc);
  61     struct pcap_sf_pkthdr hdr;
  62     int64_t ts;
  63     int caplen;
  64
  65     /* Early return in case of previous error. */
  66     if (s->fd < 0) {
  67         return size;
  68     }
  69
  70     ts = muldiv64(qemu_get_clock_ns(vm_clock), 1000000, get_ticks_per_sec());
  71     caplen = size > s->pcap_caplen ? s->pcap_caplen : size;
  72
  73     hdr.ts.tv_sec = ts / 1000000;
  74     hdr.ts.tv_usec = ts % 1000000;
  75     hdr.caplen = caplen;
  76     hdr.len = size;
  77     if (write(s->fd, &hdr, sizeof(hdr)) != sizeof(hdr) ||
  78         write(s->fd, buf, caplen) != caplen) {
  79         qemu_log("-net dump write error - stop dump\n");
  80         close(s->fd);
  81         s->fd = -1;
  82     }
  83
  84     return size;
  85 }
  86
  87 static void dump_cleanup(VLANClientState *nc)
  88 {
  89     DumpState *s = DO_UPCAST(DumpState, nc, nc);
  90
  91     close(s->fd);
  92 }
  93
  94 static NetClientInfo net_dump_info = {
  95     .type = NET_CLIENT_TYPE_DUMP,
  96     .size = sizeof(DumpState),
  97     .receive = dump_receive,
  98     .cleanup = dump_cleanup,
  99 };
 100
 101 static int net_dump_init(VLANState *vlan, const char *device,
 102                          const char *name, const char *filename, int len)
 103 {
 104     struct pcap_file_hdr hdr;
 105     VLANClientState *nc;
 106     DumpState *s;
 107     int fd;
 108
 109     fd = open(filename, O_CREAT | O_WRONLY | O_BINARY, 0644);
 110     if (fd < 0) {
 111         error_report("-net dump: can't open %s", filename);
 112         return -1;
 113     }
 114
 115     hdr.magic = PCAP_MAGIC;
 116     hdr.version_major = 2;
 117     hdr.version_minor = 4;
 118     hdr.thiszone = 0;
 119     hdr.sigfigs = 0;
 120     hdr.snaplen = len;
 121     hdr.linktype = 1;
 122
 123     if (write(fd, &hdr, sizeof(hdr)) < sizeof(hdr)) {
 124         error_report("-net dump write error: %s", strerror(errno));
 125         close(fd);
 126         return -1;
 127     }
 128
 129     nc = qemu_new_net_client(&net_dump_info, vlan, NULL, device, name);
 130
 131     snprintf(nc->info_str, sizeof(nc->info_str),
 132              "dump to %s (len=%d)", filename, len);
 133
 134     s = DO_UPCAST(DumpState, nc, nc);
 135
 136     s->fd = fd;
 137     s->pcap_caplen = len;
 138
 139     return 0;
 140 }
 141
 142 int net_init_dump(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan)
 143 {
 144     int len;
 145     const char *file;
 146     char def_file[128];
 147
 148     assert(vlan);
 149
 150     file = qemu_opt_get(opts, "file");
 151     if (!file) {
 152         snprintf(def_file, sizeof(def_file), "qemu-vlan%d.pcap", vlan->id);
 153         file = def_file;
 154     }
 155
 156     len = qemu_opt_get_size(opts, "len", 65536);
 157
 158     return net_dump_init(vlan, "dump", name, file, len);
 159 }