qemu/net/dump.c
Markus Armbruster 3791f83ca9 net/dump: Improve -net/host_net_add dump error reporting
When -net dump fails, it first reports a specific error, then a
generic one, like this:

    $ qemu-system-x86_64 -net dump,id=foo,file=/eperm
    qemu-system-x86_64: -net dump,id=foo,file=/eperm: -net dump: can't open /eperm
    qemu-system-x86_64: -net dump,id=foo,file=/eperm: Device 'dump' could not be initialized

Convert net_init_tap() to Error.  This suppresses the unwanted second
message.

Improve the error messages to include strerror(errno) where
appropriate.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1431691143-1015-5-git-send-email-armbru@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-05-27 09:51:05 +01:00

187 lines
4.8 KiB
C

/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "clients.h"
#include "qemu-common.h"
#include "qemu/error-report.h"
#include "qemu/log.h"
#include "qemu/timer.h"
#include "hub.h"
typedef struct DumpState {
NetClientState nc;
int64_t start_ts;
int fd;
int pcap_caplen;
} DumpState;
#define PCAP_MAGIC 0xa1b2c3d4
struct pcap_file_hdr {
uint32_t magic;
uint16_t version_major;
uint16_t version_minor;
int32_t thiszone;
uint32_t sigfigs;
uint32_t snaplen;
uint32_t linktype;
};
struct pcap_sf_pkthdr {
struct {
int32_t tv_sec;
int32_t tv_usec;
} ts;
uint32_t caplen;
uint32_t len;
};
static ssize_t dump_receive(NetClientState *nc, const uint8_t *buf, size_t size)
{
DumpState *s = DO_UPCAST(DumpState, nc, nc);
struct pcap_sf_pkthdr hdr;
int64_t ts;
int caplen;
/* Early return in case of previous error. */
if (s->fd < 0) {
return size;
}
ts = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), 1000000, get_ticks_per_sec());
caplen = size > s->pcap_caplen ? s->pcap_caplen : size;
hdr.ts.tv_sec = ts / 1000000 + s->start_ts;
hdr.ts.tv_usec = ts % 1000000;
hdr.caplen = caplen;
hdr.len = size;
if (write(s->fd, &hdr, sizeof(hdr)) != sizeof(hdr) ||
write(s->fd, buf, caplen) != caplen) {
qemu_log("-net dump write error - stop dump\n");
close(s->fd);
s->fd = -1;
}
return size;
}
static void dump_cleanup(NetClientState *nc)
{
DumpState *s = DO_UPCAST(DumpState, nc, nc);
close(s->fd);
}
static NetClientInfo net_dump_info = {
.type = NET_CLIENT_OPTIONS_KIND_DUMP,
.size = sizeof(DumpState),
.receive = dump_receive,
.cleanup = dump_cleanup,
};
static int net_dump_init(NetClientState *peer, const char *device,
const char *name, const char *filename, int len,
Error **errp)
{
struct pcap_file_hdr hdr;
NetClientState *nc;
DumpState *s;
struct tm tm;
int fd;
fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0644);
if (fd < 0) {
error_setg_errno(errp, errno, "-net dump: can't open %s", filename);
return -1;
}
hdr.magic = PCAP_MAGIC;
hdr.version_major = 2;
hdr.version_minor = 4;
hdr.thiszone = 0;
hdr.sigfigs = 0;
hdr.snaplen = len;
hdr.linktype = 1;
if (write(fd, &hdr, sizeof(hdr)) < sizeof(hdr)) {
error_setg_errno(errp, errno, "-net dump write error");
close(fd);
return -1;
}
nc = qemu_new_net_client(&net_dump_info, peer, device, name);
snprintf(nc->info_str, sizeof(nc->info_str),
"dump to %s (len=%d)", filename, len);
s = DO_UPCAST(DumpState, nc, nc);
s->fd = fd;
s->pcap_caplen = len;
qemu_get_timedate(&tm, 0);
s->start_ts = mktime(&tm);
return 0;
}
int net_init_dump(const NetClientOptions *opts, const char *name,
NetClientState *peer, Error **errp)
{
int len;
const char *file;
char def_file[128];
const NetdevDumpOptions *dump;
assert(opts->kind == NET_CLIENT_OPTIONS_KIND_DUMP);
dump = opts->dump;
assert(peer);
if (dump->has_file) {
file = dump->file;
} else {
int id;
int ret;
ret = net_hub_id_for_client(peer, &id);
assert(ret == 0); /* peer must be on a hub */
snprintf(def_file, sizeof(def_file), "qemu-vlan%d.pcap", id);
file = def_file;
}
if (dump->has_len) {
if (dump->len > INT_MAX) {
error_setg(errp, "invalid length: %"PRIu64, dump->len);
return -1;
}
len = dump->len;
} else {
len = 65536;
}
return net_dump_init(peer, "dump", name, file, len, errp);
}