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authoraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2009-04-21 19:56:28 +0000
committeraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2009-04-21 19:56:28 +0000
commitbb9ea79e7a177acce6f8017eef794662ee219c97 (patch)
treedd78593ce2df52356b297dae8185a0cc5bd2e0e4
parent1030021681e385ec0299a5f0f685b263db81bbb5 (diff)
net: Add support for capturing VLANs (Jan Kiszka)
This patch is derived from Tristan Gingold's patch. It adds a new VLAN client type that writes all traffic on the VLAN it is attached to into a pcap file. Such a file can then be analyzed offline with Wireshark or tcpdump. Besides rebasing and some minor cleanups, the major differences to the original version are: - support for enabling/disabling via the monitor (host_net_add/remove) - no special ordering of VLAN client list, qemu_send_packet now takes care of properly ordered packets - 64k default capturing limit (I hate tcpdump's default) Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7200 c046a42c-6fe2-441c-8c8c-71466251a162
-rw-r--r--monitor.c2
-rw-r--r--net.c115
-rw-r--r--qemu-options.hx7
3 files changed, 121 insertions, 3 deletions
diff --git a/monitor.c b/monitor.c
index e7a4dc795d..b323af94ba 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1731,7 +1731,7 @@ static const mon_cmd_t mon_cmds[] = {
{ "pci_add", "sss", pci_device_hot_add, "pci_addr=auto|[[<domain>:]<bus>:]<slot> nic|storage [[vlan=n][,macaddr=addr][,model=type]] [file=file][,if=type][,bus=nr]...", "hot-add PCI device" },
{ "pci_del", "s", pci_device_hot_remove, "pci_addr=[[<domain>:]<bus>:]<slot>", "hot remove PCI device" },
{ "host_net_add", "ss", net_host_device_add,
- "[tap,user,socket,vde] options", "add host VLAN client" },
+ "[tap,user,socket,vde,dump] options", "add host VLAN client" },
{ "host_net_remove", "is", net_host_device_remove,
"vlan_id name", "remove host VLAN client" },
#endif
diff --git a/net.c b/net.c
index c6b196fb93..7139f4f898 100644
--- a/net.c
+++ b/net.c
@@ -118,6 +118,7 @@
#include "qemu-char.h"
#include "audio/audio.h"
#include "qemu_socket.h"
+#include "qemu-log.h"
#if defined(CONFIG_SLIRP)
#include "libslirp.h"
@@ -1558,6 +1559,106 @@ static int net_socket_mcast_init(VLANState *vlan,
}
+typedef struct DumpState {
+ VLANClientState *pcap_vc;
+ 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 void dump_receive(void *opaque, const uint8_t *buf, int size)
+{
+ DumpState *s = opaque;
+ struct pcap_sf_pkthdr hdr;
+ int64_t ts;
+ int caplen;
+
+ /* Early return in case of previous error. */
+ if (s->fd < 0) {
+ return;
+ }
+
+ ts = muldiv64 (qemu_get_clock(vm_clock),1000000, ticks_per_sec);
+ caplen = size > s->pcap_caplen ? s->pcap_caplen : size;
+
+ hdr.ts.tv_sec = ts / 1000000000LL;
+ 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;
+ }
+}
+
+static void net_dump_cleanup(VLANClientState *vc)
+{
+ DumpState *s = vc->opaque;
+
+ close(s->fd);
+ qemu_free(s);
+}
+
+static int net_dump_init(VLANState *vlan, const char *device,
+ const char *name, const char *filename, int len)
+{
+ struct pcap_file_hdr hdr;
+ DumpState *s;
+
+ s = qemu_malloc(sizeof(DumpState));
+
+ s->fd = open(filename, O_CREAT | O_WRONLY, 0644);
+ if (s->fd < 0) {
+ fprintf(stderr, "-net dump: can't open %s\n", filename);
+ return -1;
+ }
+
+ s->pcap_caplen = len;
+
+ hdr.magic = PCAP_MAGIC;
+ hdr.version_major = 2;
+ hdr.version_minor = 4;
+ hdr.thiszone = 0;
+ hdr.sigfigs = 0;
+ hdr.snaplen = s->pcap_caplen;
+ hdr.linktype = 1;
+
+ if (write(s->fd, &hdr, sizeof(hdr)) < sizeof(hdr)) {
+ perror("-net dump write error");
+ close(s->fd);
+ qemu_free(s);
+ return -1;
+ }
+
+ s->pcap_vc = qemu_new_vlan_client(vlan, device, name, dump_receive, NULL,
+ net_dump_cleanup, s);
+ snprintf(s->pcap_vc->info_str, sizeof(s->pcap_vc->info_str),
+ "dump to %s (len=%d)", filename, len);
+ return 0;
+}
+
/* find or alloc a new VLAN */
VLANState *qemu_find_vlan(int id)
{
@@ -1883,7 +1984,17 @@ int net_client_init(const char *device, const char *p)
ret = net_vde_init(vlan, device, name, vde_sock, vde_port, vde_group, vde_mode);
} else
#endif
- {
+ if (!strcmp(device, "dump")) {
+ int len = 65536;
+
+ if (get_param_value(buf, sizeof(buf), "len", p) > 0) {
+ len = strtol(buf, NULL, 0);
+ }
+ if (!get_param_value(buf, sizeof(buf), "file", p)) {
+ snprintf(buf, sizeof(buf), "qemu-vlan%d.pcap", vlan_id);
+ }
+ ret = net_dump_init(vlan, device, name, buf, len);
+ } else {
fprintf(stderr, "Unknown network device: %s\n", device);
ret = -1;
goto out;
@@ -1908,7 +2019,7 @@ void net_client_uninit(NICInfo *nd)
static int net_host_check_device(const char *device)
{
int i;
- const char *valid_param_list[] = { "tap", "socket"
+ const char *valid_param_list[] = { "tap", "socket", "dump"
#ifdef CONFIG_SLIRP
,"user"
#endif
diff --git a/qemu-options.hx b/qemu-options.hx
index 1d783e561c..718b10a919 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -745,6 +745,8 @@ DEF("net", HAS_ARG, QEMU_OPTION_net, \
" Use group 'groupname' and mode 'octalmode' to change default\n"
" ownership and permissions for communication port.\n"
#endif
+ "-net dump[,vlan=n][,file=f][,len=n]\n"
+ " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n"
"-net none use it alone to have zero network devices; if no -net option\n"
" is provided, the default is '-net nic -net user'\n")
STEXI
@@ -865,6 +867,11 @@ vde_switch -F -sock /tmp/myswitch
qemu linux.img -net nic -net vde,sock=/tmp/myswitch
@end example
+@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
+Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
+At most @var{len} bytes (64k by default) per packet are stored. The file format is
+libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
+
@item -net none
Indicate that no network devices should be configured. It is used to
override the default configuration (@option{-net nic -net user}) which