qemu/net/dump.c
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   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/module.h"
  32#include "qemu/timer.h"
  33#include "qapi/visitor.h"
  34#include "net/filter.h"
  35#include "qom/object.h"
  36
  37typedef struct DumpState {
  38    int64_t start_ts;
  39    int fd;
  40    int pcap_caplen;
  41} DumpState;
  42
  43#define PCAP_MAGIC 0xa1b2c3d4
  44
  45struct 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
  55struct 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
  64static 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
  98static void dump_cleanup(DumpState *s)
  99{
 100    close(s->fd);
 101    s->fd = -1;
 102}
 103
 104static 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
 142OBJECT_DECLARE_SIMPLE_TYPE(NetFilterDumpState, FILTER_DUMP)
 143
 144struct NetFilterDumpState {
 145    NetFilterState nfs;
 146    DumpState ds;
 147    char *filename;
 148    uint32_t maxlen;
 149};
 150
 151static ssize_t filter_dump_receive_iov(NetFilterState *nf, NetClientState *sndr,
 152                                       unsigned flags, const struct iovec *iov,
 153                                       int iovcnt, NetPacketSent *sent_cb)
 154{
 155    NetFilterDumpState *nfds = FILTER_DUMP(nf);
 156
 157    dump_receive_iov(&nfds->ds, iov, iovcnt);
 158    return 0;
 159}
 160
 161static void filter_dump_cleanup(NetFilterState *nf)
 162{
 163    NetFilterDumpState *nfds = FILTER_DUMP(nf);
 164
 165    dump_cleanup(&nfds->ds);
 166}
 167
 168static void filter_dump_setup(NetFilterState *nf, Error **errp)
 169{
 170    NetFilterDumpState *nfds = FILTER_DUMP(nf);
 171
 172    if (!nfds->filename) {
 173        error_setg(errp, "dump filter needs 'file' property set!");
 174        return;
 175    }
 176
 177    net_dump_state_init(&nfds->ds, nfds->filename, nfds->maxlen, errp);
 178}
 179
 180static void filter_dump_get_maxlen(Object *obj, Visitor *v, const char *name,
 181                                   void *opaque, Error **errp)
 182{
 183    NetFilterDumpState *nfds = FILTER_DUMP(obj);
 184    uint32_t value = nfds->maxlen;
 185
 186    visit_type_uint32(v, name, &value, errp);
 187}
 188
 189static void filter_dump_set_maxlen(Object *obj, Visitor *v, const char *name,
 190                                   void *opaque, Error **errp)
 191{
 192    NetFilterDumpState *nfds = FILTER_DUMP(obj);
 193    uint32_t value;
 194
 195    if (!visit_type_uint32(v, name, &value, errp)) {
 196        return;
 197    }
 198    if (value == 0) {
 199        error_setg(errp, "Property '%s.%s' doesn't take value '%u'",
 200                   object_get_typename(obj), name, value);
 201        return;
 202    }
 203    nfds->maxlen = value;
 204}
 205
 206static char *file_dump_get_filename(Object *obj, Error **errp)
 207{
 208    NetFilterDumpState *nfds = FILTER_DUMP(obj);
 209
 210    return g_strdup(nfds->filename);
 211}
 212
 213static void file_dump_set_filename(Object *obj, const char *value, Error **errp)
 214{
 215   NetFilterDumpState *nfds = FILTER_DUMP(obj);
 216
 217    g_free(nfds->filename);
 218    nfds->filename = g_strdup(value);
 219}
 220
 221static void filter_dump_instance_init(Object *obj)
 222{
 223    NetFilterDumpState *nfds = FILTER_DUMP(obj);
 224
 225    nfds->maxlen = 65536;
 226}
 227
 228static void filter_dump_instance_finalize(Object *obj)
 229{
 230    NetFilterDumpState *nfds = FILTER_DUMP(obj);
 231
 232    g_free(nfds->filename);
 233}
 234
 235static void filter_dump_class_init(ObjectClass *oc, void *data)
 236{
 237    NetFilterClass *nfc = NETFILTER_CLASS(oc);
 238
 239    object_class_property_add(oc, "maxlen", "uint32", filter_dump_get_maxlen,
 240                              filter_dump_set_maxlen, NULL, NULL);
 241    object_class_property_add_str(oc, "file", file_dump_get_filename,
 242                                  file_dump_set_filename);
 243
 244    nfc->setup = filter_dump_setup;
 245    nfc->cleanup = filter_dump_cleanup;
 246    nfc->receive_iov = filter_dump_receive_iov;
 247}
 248
 249static const TypeInfo filter_dump_info = {
 250    .name = TYPE_FILTER_DUMP,
 251    .parent = TYPE_NETFILTER,
 252    .class_init = filter_dump_class_init,
 253    .instance_init = filter_dump_instance_init,
 254    .instance_finalize = filter_dump_instance_finalize,
 255    .instance_size = sizeof(NetFilterDumpState),
 256};
 257
 258static void filter_dump_register_types(void)
 259{
 260    type_register_static(&filter_dump_info);
 261}
 262
 263type_init(filter_dump_register_types);
 264