美好的一天，先生们。
我最近遇到一个问题，通过 StrongSwan 连接到 FreeBSD 服务器的设备无法路由到其子网之外。我来详细解释一下：
FreeBSD 10.0-RELEASE，内核编译（完整配置：http://pastebin.com/5PQFXqhx）：
options IPSEC
options IPSEC_NAT_T
device crypto
device cryptodev
转发开启于系统配置文件:
net.inet.ip.forwarding=1
net.inet6.ip6.forwarding=1
我们有两个接口。第一个是 192.168.1.100，路由器将端口 500 和 4500 从 Internet 转发到此 IP（因此我们可以从任何地方连接到“甜蜜之家”网络）。第二个是 10.0.0.1，用于 Samba 和其他服务。
/etc/rc.conf:
hostname="bsdserver"
ifconfig_igb0="inet 192.168.1.100 netmask 255.255.255.0"
ifconfig_igb1="inet 10.0.0.1 netmask 255.255.255.0"
defaultrouter="192.168.1.1"
gateway_enable="YES"
ipv6_gateway_enable="YES"
ipsec配置文件:
config setup
strictcrlpolicy = no
ca bsdserver
cacert = /usr/local/etc/ipsec.d/cacerts/bsdserver_CA.der
conn android
auto = add
dpdaction = clear
keyexchange = ikev2
esp=aes-aes256-sha-modp1024,aes256-sha512-modp4096
ike=aes-aes256-sha-modp1024,aes256-sha512-modp4096
mobike = yes
left = 192.168.1.100
leftsubnet = 0.0.0.0/0,::0/0
leftauth = pubkey
leftid = "111.111.111.111" # real "white" ip here
leftcert = /usr/local/etc/ipsec.d/certs/111.111.111.111_cert.der
leftfirewall = yes
leftsourceip = %config4,%config6
right = %any
rightsourceip = 10.0.0.3/32
rightauth = pubkey
rightid = "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]"
rightcert = /usr/local/etc/ipsec.d/certs/android_cert.der
这是以下的输出ipsec start --nofork：
Starting strongSwan 5.1.1 IPsec [starter]...
no netkey IPsec stack detected
no KLIPS IPsec stack detected
no known IPsec stack detected, ignoring!
00[DMN] Starting IKE charon daemon (strongSwan 5.1.1, FreeBSD 10.0-RELEASE, amd64)
00[KNL] unable to set UDP_ENCAP: Invalid argument
00[NET] enabling UDP decapsulation for IPv6 on port 4500 failed
00[CFG] loading ca certificates from '/usr/local/etc/ipsec.d/cacerts'
00[CFG] loaded ca certificate "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]" from '/usr/local/etc/ipsec.d/cacerts/UNIT_CA.der'
00[CFG] loading aa certificates from '/usr/local/etc/ipsec.d/aacerts'
00[CFG] loading ocsp signer certificates from '/usr/local/etc/ipsec.d/ocspcerts'
00[CFG] loading attribute certificates from '/usr/local/etc/ipsec.d/acerts'
00[CFG] loading crls from '/usr/local/etc/ipsec.d/crls'
00[CFG] loading secrets from '/usr/local/etc/ipsec.secrets'
00[CFG] loaded RSA private key from '/usr/local/etc/ipsec.d/private/111.111.111.111_key.der'
00[LIB] loaded plugins: charon test-vectors curl aes des blowfish rc2 sha1 sha2 md4 md5 random nonce x509 revocation constraints pubkey pkcs1 pkcs7 pkcs8 pkcs12 pgp dnskey sshkey pem openssl fips-prf gmp xcbc cmac hmac attr kernel-pfkey kernel-pfroute resolve socket-default stroke updown eap-identity eap-aka eap-aka-3gpp2 eap-md5 eap-mschapv2 eap-dynamic eap-tls eap-ttls eap-peap xauth-generic xauth-eap whitelist addrblock
00[LIB] unable to load 4 plugin features (4 due to unmet dependencies)
00[JOB] spawning 16 worker threads
charon (49667) started after 220 ms
16[CFG] received stroke: add connection 'android'
16[CFG] adding virtXXl IP address pool 10.0.0.3/32
16[CFG] 'android' has both left- and rightsourceip, but IKE can negotiate one virtXXl IP only, ignoring local virtXXl IP
16[CFG] loaded certificate "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]" from '/usr/local/etc/ipsec.d/certs/111.111.111.111_cert.der'
16[CFG] loaded certificate "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]" from '/usr/local/etc/ipsec.d/certs/android_cert.der'
16[CFG] added configuration 'android'
16[NET] received packet: from 22.222.222.22[16483] to 192.168.1.100[500] (660 bytes)
16[ENC] parsed IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) ]
16[IKE] 22.222.222.22 is initiating an IKE_SA
16[IKE] IKE_SA (unnamed)[1] state change: CREATED => CONNECTING
16[IKE] local host is behind NAT, sending keep alives
16[IKE] remote host is behind NAT
16[IKE] sending cert request for "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]"
16[ENC] generating IKE_SA_INIT response 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) CERTREQ N(MULT_AUTH) ]
16[NET] sending packet: from 192.168.1.100[500] to 22.222.222.22[16483] (337 bytes)
16[NET] received packet: from 22.222.222.22[16549] to 192.168.1.100[4500] (1964 bytes)
16[ENC] parsed IKE_AUTH request 1 [ IDi CERT N(INIT_CONTACT) CERTREQ AUTH CPRQ(ADDR ADDR6 DNS DNS6) N(ESP_TFC_PAD_N) SA TSi TSr N(MOBIKE_SUP) N(NO_ADD_ADDR) N(MULT_AUTH) N(EAP_ONLY) ]
16[IKE] received cert request for "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]"
16[IKE] received end entity cert "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]"
16[CFG] looking for peer configs matching 192.168.1.100[%any]...22.222.222.22[C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]]
16[CFG] selected peer config 'android'
16[CFG] using trusted ca certificate "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]"
16[CFG] checking certificate status of "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]"
16[CFG] certificate status is not available
16[CFG] reached self-signed root ca with a path length of 0
16[CFG] using trusted certificate "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]"
16[IKE] authentication of 'C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]' with RSA signature successful
16[IKE] processing INTERNAL_IP4_ADDRESS attribute
16[IKE] processing INTERNAL_IP6_ADDRESS attribute
16[IKE] processing INTERNAL_IP4_DNS attribute
16[IKE] processing INTERNAL_IP6_DNS attribute
16[IKE] received ESP_TFC_PADDING_NOT_SUPPORTED, not using ESPv3 TFC padding
16[IKE] peer supports MOBIKE
16[IKE] authentication of '111.111.111.111' (myself) with RSA signature successful
16[IKE] IKE_SA android[1] established between 192.168.1.100[111.111.111.111]...22.222.222.22[C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]]
16[IKE] IKE_SA android[1] state change: CONNECTING => ESTABLISHED
16[IKE] scheduling reauthentication in 9802s
16[IKE] maximum IKE_SA lifetime 10342s
16[IKE] sending end entity cert "C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]"
16[IKE] peer requested virtXXl IP %any
16[CFG] assigning new lease to 'C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]'
16[IKE] assigning virtXXl IP 10.0.0.3 to peer 'C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]'
16[IKE] peer requested virtXXl IP %any6
16[IKE] no virtXXl IP found for %any6 requested by 'C=XX, ST=XX, L=XX, O=ORG, OU=UNIT, CN=111.111.111.111, [email protected]'
16[IKE] CHILD_SA android{1} established with SPIs c11f2b7e_i f7ac6573_o and TS 0.0.0.0/0 ::/0 === 10.0.0.3/32
16[CHD] updown: /usr/local/libexec/ipsec/_updown: iptables: not found
16[CHD] updown: /usr/local/libexec/ipsec/_updown: iptables: not found
16[ENC] generating IKE_AUTH response 1 [ IDr CERT AUTH CPRP(ADDR) N(ESP_TFC_PAD_N) SA TSi TSr N(AUTH_LFT) N(MOBIKE_SUP) N(ADD_4_ADDR) ]
16[NET] sending packet: from 192.168.1.100[4500] to 22.222.222.22[16549] (1596 bytes)
查看tcpdump输出：10.0.0.3 是 Android 客户端由 StrongSwan 分配的 IP。
域名系统：
22:21:43.971797 IP 10.0.0.3.55123 > ns1.kyivstar.net.domain: 41221+ A? www.cdn.viber.com. (35)
22:26:00.484696 IP 10.0.0.3.25462 > gi-dns1-kie3.kyivstar.net.domain: 436+ A? mtalk.google.com. (34)
22:25:59.225291 IP 10.0.0.3.53999 > ns1.kyivstar.net.domain: 56585+ A? graph.facebook.com. (36)
好的，ping “bsdserver” 有效：
22:26:06.460464 IP 22-222-222-22-gprs.kyivstar.net.16445 > bsdserver.local.sae-urn: UDP-encap: ESP(spi=0xc289c560,seq=0x96), length 132
22:26:06.460749 IP bsdserver.local.sae-urn > 46-211-183-74-gprs.kyivstar.net.16445: UDP-encap: ESP(spi=0xe77a2567,seq=0x1f), length 132
但 ping 8.8.8.8 却没有：
22:30:51.179070 IP 10.0.0.3 > google-public-dns-a.google.com: ICMP echo request, id 3, seq 6, length 64
22:30:52.098315 IP 22-222-222-22-gprs.kyivstar.net.16445 > bsdserver.local.sae-urn: UDP-encap: ESP(spi=0xc289c560,seq=0xce), length 132
22:30:52.098825 IP 10.0.0.3 > google-public-dns-a.google.com: ICMP echo request, id 3, seq 7, length 64
22:30:52.754209 STP 802.1d, Config, Flags [none], bridge-id 8000.b0:48:7a:c2:f2:92.8001, length 43
22:30:53.078436 IP 22-222-222-22-gprs.kyivstar.net.16445 > bsdserver.local.sae-urn: UDP-encap: ESP(spi=0xc289c560,seq=0xcf), length 132
22:30:53.079070 IP 10.0.0.3 > google-public-dns-a.google.com: ICMP echo request, id 3, seq 8, length 64
22:30:53.358693 IP 22-222-222-22-gprs.kyivstar.net.16445 > bsdserver.local.sae-urn: isakmp-nat-keep-alive
22:30:53.738572 IP 22-222-222-22-gprs.kyivstar.net.16445 > bsdserver.local.sae-urn: UDP-encap: ESP(spi=0xc289c560,seq=0xd0), length 116
22:30:53.739164 IP 10.0.0.3.25984 > gi-dns1-kie3.kyivstar.net.domain: 1638+ A? www.cdn.viber.com. (35)
22:30:54.098740 IP 22-222-222-22-gprs.kyivstar.net.16445 > bsdserver.local.sae-urn: UDP-encap: ESP(spi=0xc289c560,seq=0xd1), length 132
22:30:54.099248 IP 10.0.0.3 > google-public-dns-a.google.com: ICMP echo request, id 3, seq 9, length 64
22:30:54.754083 STP 802.1d, Config, Flags [none], bridge-id 8000.b0:48:7a:c2:f2:92.8001, length 43
Android 设备的路由表：
我觉得问题与 IPsec 不完全相关。关于可能的解决方案有什么好主意吗？
答案1
您可能与该错误有关：ipfw 与解封装 ipsec 的传入数据包不匹配