Android AOSP SIOCADDRT ioctl 调用失败： 网络无法访问

Question

Android派（android-9.0.0_r16）

构建：PQ1A.181105.017. A1

设备：像素 2

我正在尝试使用 dhcp 工具（重命名为 dhcpdbg）将蜂窝调制解调器与 RNDIS 模式下的Android 9 派连接。相同的设置对于以前版本的机器人工作正常，但对于Pie，它在ioctl（3，SIOCADDRT，0x7ffb9b8030）上失败。它说“网络无法访问”。

我已经检查了ifconfig中的端口，即usb0，它枚举正确，但dhcpdbg调用失败，网络不可ping通。

设备上的分离处于允许模式。此外，dmesg 日志中没有权限或其他错误。注意：默认情况下，RNDIS 驱动程序未在Android派内核中配置，因此我们在内核中启用了 RNDIS 模式，并在 AOSP 源代码中集成了更改的内核。

以下是“strace dhcpdbg usb0”中的一些日志

ioctl(3, SIOCGIFFLAGS, {ifr_name="usb0", ifr_flags=IFF_UP|IFF_BROADCAST|IFF_RUNNING|IFF_MULTICAST}) = 0
ioctl(3, SIOCSIFFLAGS, {ifr_name="usb0", ifr_flags=IFF_UP|IFF_BROADCAST|IFF_RUNNING|IFF_MULTICAST}) = 0
ioctl(3, SIOCSIFADDR, {ifr_name="usb0", ifr_addr={sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("192.168.1.100")}}) = 0
ioctl(3, SIOCSIFNETMASK, {ifr_name="usb0", ifr_netmask={sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("255.255.255.0")}}) = 0
ioctl(3, SIOCADDRT, 0x7ffb9b8030)       = -1 ENETUNREACH (Network is unreachable)
close(3)                                = 0
getuid()                                = 0
writev(5, [{iov_base="\0\355\25o\6X\\=\267\254%", iov_len=11}, {iov_base="\3", iov_len=1}, {iov_base="DHCP\0", iov_len=5}, {iov_base="failed to set default         route 192."..., iov_len=65}], 4) = 82
getuid()                                = 0
writev(6, [{iov_base="lY\0\0\0\355\25", iov_len=7}, {iov_base="\0\355\25o\6X\\=\267\254%", iov_len=11}, {iov_base="\3", iov_len=1}, {iov_base="DHCP\0",     iov_len=5}, {iov_base="failed to set default route 192ioctl(3, SIOCADDRT, 0x7ffb9b8030)."..., iov_len=65}], 5) = 89
write(2, "dhcpdbg: ", 9dhcpdbg: )                = 9
write(2, "dhcptool usb0: do_dhcp failed", 29dhcptool usb0: do_dhcp failed) = 29
write(2, ": ", 2: )                       = 2
write(2, "Network is unreachable\n", 23Network is unreachable
) = 23
mprotect(0x6ffbc65000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x6ffbc65000, 4096, PROT_READ) = 0
mprotect(0x6ffbc65000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x6ffbc65000, 4096, PROT_READ) = 0
mprotect(0x6ffbc65000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x6ffbc65000, 4096, PROT_READ) = 0
munmap(0x6ffbc65000, 4096)              = 0
exit_group(101)                         = ?
+++ exited with 101 +++

以下是网络命令的一些输出：

ifconfig：

usb0      Link encap:Ethernet  HWaddr 02:06:06:15:00:0b  Driver rndis_host
      inet addr:192.168.1.100  Bcast:192.168.1.255  Mask:255.255.255.0 
      UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
      RX packets:4 errors:0 dropped:0 overruns:0 frame:0 
      TX packets:80 errors:0 dropped:0 overruns:0 carrier:0 
      collisions:0 txqueuelen:1000 
      RX bytes:1312 TX bytes:25155 

ip添加显示:

28: usb0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 02:06:06:15:00:0b brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.100/24 brd 192.168.1.255 scope global usb0
    valid_lft forever preferred_lft forever

IP路由显示：

192.168.1.0/24 dev usb0 proto kernel scope link src 192.168.1.100 
192.168.43.0/24 dev wlan0 proto kernel scope link src 192.168.43.222 

内核 IP 路由表：

Destination Gateway     Genmask     Flags   MSS Window  irtt Iface
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 usb0
192.168.43.0    0.0.0.0         255.255.255.0   U         0 0          0 wlan0

ping 8.8.8:

connect: Network is unreachable

这个dhcp工具工具在所有早期的Android版本上运行良好，直到Android8。以下是在同一usb0端口上运行的Android 8 dhcp工具的工作记录。

ioctl(3, SIOCGIFFLAGS, {ifr_name="usb0", ifr_flags=IFF_UP|IFF_BROADCAST|IFF_RUNNING|IFF_MULTICAST}) = 0
ioctl(3, SIOCSIFFLAGS, {ifr_name="usb0", ifr_flags=IFF_UP|IFF_BROADCAST|IFF_RUNNING|IFF_MULTICAST}) = 0
ioctl(3, SIOCSIFADDR, {ifr_name="usb0", ifr_addr={sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("192.168.1.100")}}) = 0
ioctl(3, SIOCSIFNETMASK, {ifr_name="usb0", ifr_netmask={sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("255.255.255.0")}}) = 0
ioctl(3, SIOCADDRT, 0x7fd2bb6cd0)       = 0
close(3)                                = 0
socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0) = 3
connect(3, {sa_family=AF_UNIX, sun_path="/dev/socket/property_service"}, 31) = 0
writev(3, [{iov_base="\1\0\2\0", iov_len=4}, {iov_base="\r\0\0\0", iov_len=4}, {iov_base="net.usb0.dns1", iov_len=13}, {iov_base="\v\0\0\0", iov_len=4}, {iov_base="192.168.1.1", iov_len=11}], 5) = 36
recvfrom(3, "\0\0\0\0", 4, MSG_WAITALL, NULL, NULL) = 4
close(3)                                = 0
socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0) = 3
connect(3, {sa_family=AF_UNIX, sun_path="/dev/socket/property_service"}, 31) = 0
writev(3, [{iov_base="\1\0\2\0", iov_len=4}, {iov_base="\r\0\0\0", iov_len=4}, {iov_base="net.usb0.dns2", iov_len=13}, {iov_base="\0\0\0\0", iov_len=4}], 4) = 25
recvfrom(3, "\0\0\0\0", 4, MSG_WAITALL, NULL, NULL) = 4
close(3)                                = 0
write(2, "dhcptool: ", 10dhcptool: )              = 10
write(2, "IP assignment is for debug purpo"..., 40IP assignment is for debug purposes ONLY) = 40
write(2, ": ", 2: )                       = 2
write(2, "Success\n", 8Success
)                = 8
mprotect(0x7729153000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x7729153000, 4096, PROT_READ) = 0
mprotect(0x7729153000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x7729153000, 4096, PROT_READ) = 0
munmap(0x7729153000, 4096)              = 0
exit_group(0)                           = ?
+++ exited with 0 +++
bullhead:/ # ping 8.8.8.8                                                                                                                                                                                   
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=114 time=131 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=114 time=58.4 ms
^C
--- 8.8.8.8 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 58.496/95.044/131.592/36.548 ms
bullhead:/ # 

Answer 1

请参阅 https://elinux.org/Android_Networking#Setting_up_networking_on_bootup。命令

netcfg eth0 dhcp
setprop net.dns1 8.8.8.8

应该足够了。

Answer 2

从上面共享的信息中，似乎缺少默认路由。您可以使用下面的命令添加默认路由：

ip route add default dev usb0

添加上面的路由后，我建议您使用跟踪路由工具或ping（如果跟踪路由不可用，则修改TTL）来跟踪更远的数据包。

Answer 3

似乎您缺少一条到8.8.8的路线（可能是默认路线）。比较工作和非工作设置之间的路线。