strongswan sa
该系列文章的全部内容都是基于 strongswan 5.7.2版本
目录
资料
https://wiki.strongswan.org/projects/strongswan/wiki/IntroductionTostrongSwan
编译
略
启动
ipsec start
rpm安装的
[root@D129 ~]# systemctl start strongswan
[root@D129 ~]# swanctl --version
strongSwan swanctl 5.7.1
[root@D129 ~]#
注：通过rpm安装的已经没有ipsec命令了，只有swanctl命令。
进程信息
TODO
结构
- start daemon
- keying daemon
架构图与插件
TODO
查看插件
[root@T9 sbin]# ./swanctl --stats
uptime: 2 minutes, since Dec 14 16:04:11 2018
worker threads: 16 total, 11 idle, working: 4/0/1/0
job queues: 0/0/0/0
jobs scheduled: 0
IKE_SAs: 0 total, 0 half-open
mallinfo: sbrk 2297856, mmap 0, used 288560, free 2009296
loaded plugins: charon aes des rc2 sha2 sha1 md5 mgf1 random nonce x509 revocation constraints pubkey pkcs1 pkcs7 pkcs8 pkcs12 pgp dnskey sshkey pem fips-prf gmp curve25519 xcbc cmac hmac attr kernel-netlink resolve socket-default stroke vici updown xauth-generic counters
配置运行
传统配置方法
使用ipsec命令（ipsec stroke接口）和ipsec.conf and ipsec.secrets配置文件。
新的配置方法
使用swanctl命令（vici接口）swanctl命令和swanctl.conf配置文件。
strongswang.conf中是全局和插件配置。
其他配置方法
- 使用数据库插件，在数据库中进行配置。
- 使用其他插件，如networkmanager等。
详细的配置文档
- 看ipsec.conf和swanctl.conf的注释。
- man
man -M ../share/man/ strongswan.conf
man -M ../share/man/ swanctl.conf
man -M ../share/man/ ipsec.conf.5
配置示例
[root@T9 OUTPUT]# cat ./etc/swanctl/conf.d/test.conf
connections {
net-net {
remote_addrs = 192.168.7.129
ppk_id = mykey
ppk_required = yes
local {
auth = psk
}
remote {
auth = psk
}
children {
net-net {
local_ts = 10.129.0.0/16
remote_ts = 10.9.0.0/16
}
}
}
}
secrets {
ppk {
secret = 1234
id = mykey
}
}
重新加载
[root@D129 ~]# swanctl --load-all
loaded ppk secret 'ppk'
no authorities found, 0 unloaded
no pools found, 0 unloaded
loaded connection 'net-net'
successfully loaded 1 connections, 0 unloaded
[root@D129 ~]# swanctl --list-conn
net-net: IKEv1/2, no reauthentication, rekeying every 14400s
ppk: mykey, required
local: %any
remote: 192.168.7.9
local pre-shared key authentication:
remote pre-shared key authentication:
net-net: TUNNEL, rekeying every 3600s
local: 10.9.0.0/16
remote: 10.129.0.0/16
用法
ipsec up <name>
ipsec down <name>
ipsec reload
ipsec update
ipsec restart
ipsec list
ipsec status
ipsec statusall
logs
日志文件定义在strongswan.conf中。
使用ipsec start --nofork, 日志会输出在console，用来debug。
加密库
三个加密库任选其一：
libgmp
默认使用的，GNU的
libcrypto
openssl的库
libgcrypto
也是GNU的。www.gnupg.org
依赖的内核模块
ah4
ah6
esp4
esp6
xfrm4_tunnel
xfrm6_tunnel
xfrm_user
ip_tunnel
tunnel
tunnel6
xfrm4_mode_tunnel
xfrm6_mode_tunnel
祥见：http://wiki.strongswan.org/projects/strongswan/wiki/KernelModules
child sa
构成
A CHILD_SA consists of two components:
The actual __IPsec SAs__ (there are two, one in each direction) describing
the algorithms and keys used to encrypt and authenticate the traffic
The __policies__ (there are at least two) that define which network
traffic shall use such an SA.
定义
strongSwan installs the negotiated IPsec SAs and SPs into the kernel
by using a platform dependent kernel API.
The actual IPsec traffic is not handled by strongSwan but instead by
the network and IPsec stack of the operating system kernel.
sa信息查看与调试
ip xfrm status
ip xfrm policy
使用-s能查看更丰富的信息。
证书
- 使用ipsec kpi可以生成。
见：https://wiki.strongswan.org/projects/strongswan/wiki/SimpleCA - 使用openssl生成。
转发
隧道
路由
略
MSS/MTU
https://wiki.strongswan.org/projects/strongswan/wiki/ForwardingAndSplitTunneling#MTUMSS-issues
VICI interface
https://wiki.strongswan.org/projects/strongswan/wiki/Vici
编译DEBUG
./configure --prefix=/root/OUTPUT --exec-prefix=/root/OUTPUT CFLAGS="-g -O0"
gdb
只启动 charon一个daemon进程，功能也是正常的。
gdb /root/OUTPUT/libexec/ipsec/charon
./swanctl --load-all
./ipsec up net-net
代码
charon进程的入口
src/charon/charon.c:main()
接口
./src/libcharon/kernel/kernel_interface.c
架构流程图
传统方式启动并加载ipsec的流程图
通过plugin方式调用ipsec调用内核接口的原理
system的方式启动并加载ipsec的流程图
ipsec初始化
接口
sa的参数：
src/libcharon/kernel/kernel_ipsec.h
struct kernel_ipsec_add_sa_t
调用栈
#0 add_ipsec_interface (this=0x60de50, constructor=0x7ffff305ef82 <kernel_netlink_ipsec_create>)
at kernel/kernel_interface.c:738
#1 0x00007ffff78c66fc in kernel_ipsec_register (plugin=0x62e990, feature=0x7ffff326d298 <f.9409+24>, reg=true,
data=0x7ffff305ef82 <kernel_netlink_ipsec_create>) at kernel/kernel_ipsec.c:28
#2 0x00007ffff7b9d82a in plugin_feature_load (plugin=0x62e990, feature=0x7ffff326d298 <f.9409+24>,
reg=0x7ffff326d280 <f.9409>) at plugins/plugin_feature.c:451
#3 0x00007ffff7b9aec5 in load_feature (this=0x60a590, provided=0x62f420, level=4) at plugins/plugin_loader.c:786
#4 0x00007ffff7b9b12a in load_provided (this=0x60a590, provided=0x62f420, level=3)
at plugins/plugin_loader.c:861
#5 0x00007ffff7b9ab54 in load_registered (this=0x60a590, registered=0x62f300, level=3)
at plugins/plugin_loader.c:688
#6 0x00007ffff7b9ac8b in load_dependencies (this=0x60a590, provided=0x630810, level=3)
at plugins/plugin_loader.c:730
#7 0x00007ffff7b9ae98 in load_feature (this=0x60a590, provided=0x630810, level=3) at plugins/plugin_loader.c:784
#8 0x00007ffff7b9b12a in load_provided (this=0x60a590, provided=0x630810, level=2)
at plugins/plugin_loader.c:861
#9 0x00007ffff7b9ab54 in load_registered (this=0x60a590, registered=0x6306f0, level=2)
at plugins/plugin_loader.c:688
#10 0x00007ffff7b9ac8b in load_dependencies (this=0x60a590, provided=0x610550, level=2)
at plugins/plugin_loader.c:730
#11 0x00007ffff7b9ae98 in load_feature (this=0x60a590, provided=0x610550, level=2) at plugins/plugin_loader.c:784
#12 0x00007ffff7b9b12a in load_provided (this=0x60a590, provided=0x610550, level=1)
at plugins/plugin_loader.c:861
#13 0x00007ffff7b9ab54 in load_registered (this=0x60a590, registered=0x610460, level=1)
at plugins/plugin_loader.c:688
#14 0x00007ffff7b9ac8b in load_dependencies (this=0x60a590, provided=0x60f830, level=1)
at plugins/plugin_loader.c:730
#15 0x00007ffff7b9ae98 in load_feature (this=0x60a590, provided=0x60f830, level=1) at plugins/plugin_loader.c:784
#16 0x00007ffff7b9b12a in load_provided (this=0x60a590, provided=0x60f830, level=0)
at plugins/plugin_loader.c:861
#17 0x00007ffff7b9b196 in load_features (this=0x60a590) at plugins/plugin_loader.c:882
#18 0x00007ffff7b9c0e0 in load_plugins (this=0x60a590,
list=0x402d48 "aes des rc2 sha2 sha1 md5 mgf1 random nonce x509 revocation constraints pubkey pkcs1 pkcs7 pkcs8 pkcs12 pgp dnskey sshkey pem fips-prf gmp curve25519 xcbc cmac hmac attr kernel-netlink resolve socket-"...)
at plugins/plugin_loader.c:1271
#19 0x00007ffff78ad2d8 in initialize (this=0x60aa90,
plugins=0x402d48 "aes des rc2 sha2 sha1 md5 mgf1 random nonce x509 revocation constraints pubkey pkcs1 pkcs7 pkcs8 pkcs12 pgp dnskey sshkey pem fips-prf gmp curve25519 xcbc cmac hmac attr kernel-netlink resolve socket-"...)
at daemon.c:900
#20 0x000000000040241b in main (argc=1, argv=0x7fffffffe4f8) at charon.c:422
add policy的调用栈
响应 swanctl --load-all命令。 调用了三次，添加了三个policy
#0 add_policy (this=0x634310, id=0x7ffff21f85c0, data=0x7ffff21f8590) at kernel_netlink_ipsec.c:2801
#1 0x00007ffff78c4b0b in add_policy (this=0x60de50, id=0x7ffff21f85c0, data=0x7ffff21f8590)
at kernel/kernel_interface.c:481
#2 0x00007ffff78cf652 in install_policies_inbound (this=0x7fffc0004510, my_addr=0x7fffc0004790,
other_addr=0x7fffc0004880, my_ts=0x7fffc0004b30, other_ts=0x7fffc0004f40, my_sa=0x7ffff21f86b0,
other_sa=0x7ffff21f86d0, type=POLICY_IPSEC, priority=POLICY_PRIORITY_ROUTED, manual_prio=0)
at sa/child_sa.c:1005
#3 0x00007ffff78cf866 in install_policies_internal (this=0x7fffc0004510, my_addr=0x7fffc0004790,
other_addr=0x7fffc0004880, my_ts=0x7fffc0004b30, other_ts=0x7fffc0004f40, my_sa=0x7ffff21f86b0,
other_sa=0x7ffff21f86d0, type=POLICY_IPSEC, priority=POLICY_PRIORITY_ROUTED, manual_prio=0, outbound=true)
at sa/child_sa.c:1077
#4 0x00007ffff78d0022 in install_policies (this=0x7fffc0004510) at sa/child_sa.c:1266
#5 0x00007ffff78e2c61 in install (this=0x60ec30, peer=0x7fffc0003c30, child=0x7fffc0002dc0)
at sa/trap_manager.c:317
#6 0x00007ffff281daa8 in run_start_action (this=0x63d760, peer_cfg=0x7fffc0003c30, child_cfg=0x7fffc0002dc0)
at vici_config.c:2072
#7 0x00007ffff281e0d8 in handle_start_actions (this=0x63d760, peer_cfg=0x7fffc0003c30, undo=false)
at vici_config.c:2233
#8 0x00007ffff281e50f in merge_config (this=0x63d760, peer_cfg=0x7fffc0003c30) at vici_config.c:2310
#9 0x00007ffff281ee8c in _cb_config_sn (request=0x7ffff21f8b90, message=0x7fffc00020e0, ctx=0x7ffff21f8b40,
name=0x7fffc0000f20 "net-net") at vici_config.c:2542
#10 0x00007ffff280d394 in parse (this=0x7fffc00020e0, ctx=0x7ffff21f8b40,
section=0x7ffff281e548 <_cb_config_sn>, kv=0x0, li=0x0, user=0x7ffff21f8b90) at vici_message.c:530
#11 0x00007ffff281eefe in _cb_load_conn (this=0x63d760, name=0x63d9f0 "load-conn", id=1, message=0x7fffc00020e0)
at vici_config.c:2554
#12 0x00007ffff280f0f6 in process_request (this=0x63ad10, name=0x7ffff21f8c30 "load-conn", id=1, data=...)
at vici_dispatcher.c:289
#13 0x00007ffff280f3c2 in _cb_inbound (this=0x63ad10, id=1, data=...) at vici_dispatcher.c:346
#14 0x00007ffff280b92f in _cb_process_queue (sel=0x7fffc0000c40) at vici_socket.c:508
#15 0x00007ffff7b9e138 in execute (this=0x7fffc0001c70) at processing/jobs/callback_job.c:77
#16 0x00007ffff7b9e6a7 in process_job (this=0x609650, worker=0x6107c0) at processing/processor.c:235
#17 0x00007ffff7b9e9a9 in process_jobs (worker=0x6107c0) at processing/processor.c:321
#18 0x00007ffff7bb6df9 in thread_main (this=0x611ab0) at threading/thread.c:331
#19 0x00007ffff7373dd5 in start_thread () from /lib64/libpthread.so.0
#20 0x00007ffff6e98ead in clone () from /lib64/libc.so.6
add sa的调用栈
响应 ipsec up net-net命令。调用两次之后又调用三次add_policy
(gdb) bt
#0 add_sa (this=0x634310, id=0x7ffff09f5930, data=0x7ffff09f58b0) at kernel_netlink_ipsec.c:1548
#1 0x00007ffff78c4962 in add_sa (this=0x60de50, id=0x7ffff09f5930, data=0x7ffff09f58b0)
at kernel/kernel_interface.c:426
#2 0x00007ffff78cf2c2 in install_internal (this=0x7fffac005220, encr=..., integ=..., spi=1610579395, cpi=0,
initiator=true, inbound=true, tfcv3=true) at sa/child_sa.c:908
#3 0x00007ffff78cf3a4 in install (this=0x7fffac005220, encr=..., integ=..., spi=1610579395, cpi=0,
initiator=true, inbound=true, tfcv3=true) at sa/child_sa.c:921
#4 0x00007ffff78f3854 in select_and_install (this=0x7fffc4002250, no_dh=true, ike_auth=true)
at sa/ikev2/tasks/child_create.c:712
#5 0x00007ffff78f6980 in process_i (this=0x7fffc4002250, message=0x7fffe0001010)
at sa/ikev2/tasks/child_create.c:1645
#6 0x00007ffff78e8dac in process_response (this=0x7fffc4001380, message=0x7fffe0001010)
at sa/ikev2/task_manager_v2.c:745
#7 0x00007ffff78eb00c in process_message (this=0x7fffc4001380, msg=0x7fffe0001010)
at sa/ikev2/task_manager_v2.c:1613
#8 0x00007ffff78d545c in process_message (this=0x7fffc4000a40, message=0x7fffe0001010) at sa/ike_sa.c:1572
#9 0x00007ffff78cabe4 in execute (this=0x7fffe00011b0) at processing/jobs/process_message_job.c:74
#10 0x00007ffff7b9e6a7 in process_job (this=0x609650, worker=0x63f650) at processing/processor.c:235
#11 0x00007ffff7b9e9a9 in process_jobs (worker=0x63f650) at processing/processor.c:321
#12 0x00007ffff7bb6df9 in thread_main (this=0x63f680) at threading/thread.c:331
#13 0x00007ffff7373dd5 in start_thread () from /lib64/libpthread.so.0
#14 0x00007ffff6e98ead in clone () from /lib64/libc.so.6
(gdb)
https://en.wikipedia.org/wiki/Policy-based_routing
http://kernelspec.blogspot.com/2014/10/ipsec-implementation-in-linux-kernel.html