We have run into some xm-test network test failures in the tests that use 
hping2 that are caused by an IP id of 0:
- hping2 uses a packet socket, so must do its own fragmentation when 
sending messages >1500 bytes.
- When fragmenting, hping2 uses the low byte of the PID as the IP id in 
each of the fragmented IP headers.
- The kernel will assign an IP id if it sees the IP id == 0 in the header 
that hping2 passes down 
 (net/ipv4/raw.c:raw_send_hdrinc())
So if the low byte of the PID is 0, every fragment will get assigned a 
unique IP id by the kernel, and 
reassembly will fail at the destination.
Jim
----------------------------------
Use explicit (IP id==packet size) on hping2 tests to avoid problems with 
IP id==0
Signed-off-by: Jim Dykman <dykman@xxxxxxxxxx>
diff -r dc213d745642 
tools/xm-test/tests/network/03_network_local_tcp_pos.py
--- a/tools/xm-test/tests/network/03_network_local_tcp_pos.py Mon May 15 
15:32:09 2006
+++ b/tools/xm-test/tests/network/03_network_local_tcp_pos.py Thu May 18 
14:19:01 2006
@@ -44,7 +44,7 @@
 lofails=""
 for size in trysizes:
 out = console.runCmd("hping2 127.0.0.1 -E /dev/urandom -q -c 20 "
- + "--fast -d " + str(size))
+ + "--fast -d " + str(size) + " -N " + str(size))
 if out["return"]:
 lofails += " " + str(size)
@@ -54,7 +54,7 @@
 ip = netdev.getNetDevIP()
 for size in trysizes:
 out = console.runCmd("hping2 " + ip + " -E /dev/urandom -q -c 20 
"
- + "--fast -d "+ str(size))
+ + "--fast -d "+ str(size) + " -N " + str(size))
 if out["return"]:
 eth0fails += " " + str(size)
 except ConsoleError, e:
diff -r dc213d745642 
tools/xm-test/tests/network/04_network_local_udp_pos.py
--- a/tools/xm-test/tests/network/04_network_local_udp_pos.py Mon May 15 
15:32:09 2006
+++ b/tools/xm-test/tests/network/04_network_local_udp_pos.py Thu May 18 
14:19:01 2006
@@ -43,7 +43,7 @@
 lofails=""
 for size in trysizes:
 out = console.runCmd("hping2 127.0.0.1 -E /dev/urandom -2 -q -c 
20 "
- + "--fast -d " + str(size))
+ + "--fast -d " + str(size) + " -N " + str(size))
 if out["return"]:
 lofails += " " + str(size)
 print out["output"]
@@ -54,7 +54,7 @@
 ip = netdev.getNetDevIP()
 for size in trysizes:
 out = console.runCmd("hping2 " + ip + " -E /dev/urandom -2 -q -c 
20 "
- + "--fast -d " + str(size))
+ + "--fast -d " + str(size) + " -N " + str(size))
 if out["return"]:
 eth0fails += " " + str(size)
 print out["output"]
diff -r dc213d745642 
tools/xm-test/tests/network/06_network_dom0_tcp_pos.py 
--- a/tools/xm-test/tests/network/06_network_dom0_tcp_pos.py Mon May 15 
15:32:09 2006
+++ b/tools/xm-test/tests/network/06_network_dom0_tcp_pos.py Thu May 18 
14:19:01 2006
@@ -44,7 +44,7 @@
 dom0ip = netdev.getDom0AliasIP()
 for size in trysizes:
 out = console.runCmd("hping2 " + dom0ip + " -E /dev/urandom -q -c 
20 "
- + "--fast -d " + str(size))
+ + "--fast -d " + str(size) + " -N " + str(size))
 if out["return"]:
 fails += " " + str(size)
 print out["output"]
diff -r dc213d745642 
tools/xm-test/tests/network/07_network_dom0_udp_pos.py
--- a/tools/xm-test/tests/network/07_network_dom0_udp_pos.py Mon May 15 
15:32:09 2006
+++ b/tools/xm-test/tests/network/07_network_dom0_udp_pos.py Thu May 18 
14:19:01 2006
@@ -43,7 +43,7 @@
 dom0ip = netdev.getDom0AliasIP()
 for size in trysizes:
 out = console.runCmd("hping2 " + dom0ip + " -E /dev/urandom -2 -q 
-c 20"
- + " --fast -d " + str(size))
+ + " --fast -d " + str(size) + " -N " + str(size))
 if out["return"]:
 fails += " " + str(size)
 print out["output"]
diff -r dc213d745642 
tools/xm-test/tests/network/12_network_domU_tcp_pos.py
--- a/tools/xm-test/tests/network/12_network_domU_tcp_pos.py Mon May 15 
15:32:09 2006
+++ b/tools/xm-test/tests/network/12_network_domU_tcp_pos.py Thu May 18 
14:19:01 2006
@@ -50,7 +50,7 @@
 ip2 = dst_netdev.getNetDevIP()
 for size in pingsizes:
 out = src_console.runCmd("hping2 " + ip2 + " -E /dev/urandom -q 
-c 20 "
- + "--fast -d " + str(size))
+ + "--fast -d " + str(size) + " -N " + str(size))
 if out["return"]:
 fails += " " + str(size)
 print out["output"]
diff -r dc213d745642 
tools/xm-test/tests/network/13_network_domU_udp_pos.py
--- a/tools/xm-test/tests/network/13_network_domU_udp_pos.py Mon May 15 
15:32:09 2006
+++ b/tools/xm-test/tests/network/13_network_domU_udp_pos.py Thu May 18 
14:19:01 2006
@@ -50,7 +50,7 @@
 ip2 = dst_netdev.getNetDevIP()
 for size in pingsizes:
 out = src_console.runCmd("hping2 " + ip2 + " -E /dev/urandom -2 
-q "
- + "-c 20 --fast -d " + str(size))
+ + "-c 20 --fast -d " + str(size) + " -N " + str(size))
 if out["return"]:
 fails += " " + str(size)
 print out["output"]

Attachment: ipid.patch
Description: Binary data

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