mirror of
https://github.com/weaveworks/scope.git
synced 2026-07-18 12:59:31 +00:00
6bb6d4dd5a
We'd like to benefit from the memory reduction from: https://github.com/google/gopacket/pull/377 I just ran: $ gvt update github.com/google/gopacket Fixes: https://github.com/weaveworks/scope/issues/2905
72 lines
1.6 KiB
Go
72 lines
1.6 KiB
Go
// Copyright 2012 Google, Inc. All rights reserved.
|
|
// Copyright 2009-2011 Andreas Krennmair. All rights reserved.
|
|
//
|
|
// Use of this source code is governed by a BSD-style license
|
|
// that can be found in the LICENSE file in the root of the source
|
|
// tree.
|
|
//
|
|
// +build !windows
|
|
|
|
package pcap
|
|
|
|
/*
|
|
#include <stdlib.h>
|
|
#include <pcap.h>
|
|
|
|
// pcap_wait returns when the next packet is available or the timeout expires.
|
|
// Since it uses pcap_get_selectable_fd, it will not work in Windows.
|
|
int pcap_wait(pcap_t *p, int usec) {
|
|
fd_set fds;
|
|
int fd;
|
|
struct timeval tv;
|
|
|
|
fd = pcap_get_selectable_fd(p);
|
|
if(fd < 0) {
|
|
return fd;
|
|
}
|
|
|
|
FD_ZERO(&fds);
|
|
FD_SET(fd, &fds);
|
|
|
|
tv.tv_sec = 0;
|
|
tv.tv_usec = usec;
|
|
|
|
if(usec != 0) {
|
|
return select(fd+1, &fds, NULL, NULL, &tv);
|
|
}
|
|
|
|
// block indefinitely if no timeout provided
|
|
return select(fd+1, &fds, NULL, NULL, NULL);
|
|
}
|
|
*/
|
|
import "C"
|
|
|
|
import (
|
|
"errors"
|
|
"unsafe"
|
|
)
|
|
|
|
func (p *Handle) openLive() error {
|
|
buf := (*C.char)(C.calloc(errorBufferSize, 1))
|
|
defer C.free(unsafe.Pointer(buf))
|
|
|
|
// Change the device to non-blocking, we'll use pcap_wait to wait until the
|
|
// handle is ready to read.
|
|
if v := C.pcap_setnonblock(p.cptr, 1, buf); v == -1 {
|
|
return errors.New(C.GoString(buf))
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// waitForPacket waits for a packet or for the timeout to expire.
|
|
func (p *Handle) waitForPacket() {
|
|
// need to wait less than the read timeout according to pcap documentation.
|
|
// timeoutMillis rounds up to at least one millisecond so we can safely
|
|
// subtract up to a millisecond.
|
|
usec := timeoutMillis(p.timeout) * 1000
|
|
usec -= 100
|
|
|
|
C.pcap_wait(p.cptr, usec)
|
|
}
|