问题描述
Scapy具有sendpfast函数，该函数使用tcpreplay发送数据包.但是，此函数首先创建一个临时的pcap文件，然后在该文件上调用tcpreplay.这增加了太多的延迟.无论如何，有没有绕过它，并直接将数据发送到tcpreplay.我知道tcpreplay可以从STDIN读取数据.
Scapy has a sendpfast function that sends packets using tcpreplay. However, this function first creates a temporary pcap file and then calls tcpreplay on that. This adds too much delay. Is there anyway to bypass it and directly send data to tcpreplay. I know that tcpreplay can read data from STDIN.
上下文:我想每秒产生大量流量(具有不同的srcIP)并通过网络发送.一种选择是将带有时间戳的所有流量保存在一个巨大的pcap文件中，然后运行tcpreplay.另一种选择是每秒发送一次数据.
Context: I want to generate large traffic (with different srcIP) every second and send it through network. One option is to save all traffic with timestamps in a giant pcap file and run tcpreplay. Another option is to send data every second.
推荐答案
不知道是否避免使用临时文件就足够了，但是仍然可以采用以下方法:
Not sure whether or not avoiding temporary file will be enough, but still, here is a way:
#! /usr/bin/env python
from scapy.all import *
def pkt2pcap(p):
sec = int(p.time)
usec = int(round((p.time-sec)*1000000))
s = str(p)
caplen = len(s)
return struct.pack("IIII", sec, usec, caplen, caplen) + s
# adapted from Scapy's sendpfast
def mysendpfast(x, pps=None, mbps=None, realtime=None, loop=0, file_cache=False, iface=None):
"""Send packets at layer 2 using tcpreplay for performance
pps: packets per second
mpbs: MBits per second
realtime: use packet's timestamp, bending time with realtime value
loop: number of times to process the packet list
file_cache: cache packets in RAM instead of reading from disk at each iteration
iface: output interface """
if iface is None:
iface = conf.iface
argv = [conf.prog.tcpreplay, "--intf1=%s" % iface ]
if pps is not None:
argv.append("--pps=%i" % pps)
elif mbps is not None:
argv.append("--mbps=%i" % mbps)
elif realtime is not None:
argv.append("--multiplier=%i" % realtime)
else:
argv.append("--topspeed")
if loop:
argv.append("--loop=%i" % loop)
if file_cache:
argv.append("--enable-file-cache")
argv.append("-")
try:
f = subprocess.Popen(argv, stdin=subprocess.PIPE)
# PCAP header
p = x.next()
f.stdin.write(struct.pack("IHHIIII", 0xa1b2c3d4L,
2, 4, 0, 0, MTU,
conf.l2types[p.__class__]))
# Let's send
f.stdin.write(pkt2pcap(p))
for p in x:
f.stdin.write(pkt2pcap(p))
f.stdin.close()
f.communicate()
except KeyboardInterrupt:
log_interactive.info("Interrupted by user")
except Exception,e:
log_interactive.error("while trying to exec [%s]: %s" % (argv[0],e))
这篇关于Scapy和tcpreplay:绕过临时文件以提高性能的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！