Android——4.2 - 3G移植之路之 reference-ril .pppd 拨号上网

采得百花成蜜后，为谁辛苦为谁甜。这篇文章主要讲述Android——4.2 - 3G移植之路之 reference-ril .pppd 拨号上网相关的知识，希望能为你提供帮助。
android的RIL机制中的 reference-ril.c 即为厂商提供的驱动接口。这个驱动源代码各个厂商都是有提供的，网上也有下载。我如今用的就是huawei wcdma的。最后编译成libreference-ril.so。关于这个接口驱动在RIL中所扮演的角色可參考 Android——RIL 机制源代码分析

android 4.2自带pppd源代码在/external/ppp/pppd中.相同，kernel中也是须要打开对point-to-point 的支持，在network support里面.

撰写不易,转载请注明出处：http://blog.csdn.net/jscese/article/details/40340665

一.requestSetupDataCall: 这个就是在reference-ril.c 中的数据流量的request，上层的接口通过onRequest 的RIL_REQUEST_SETUP_DATA_CALL请求。这些在上面说到的源代码分析里有具体分析，这里就仅仅从拨号连接分析。

static void requestSetupDataCall(void *data, size_t datalen, RIL_Token t) { const char *apn; char *cmd; int err; ATResponse *p_response = NULL; char ppp_dnses[(PROPERTY_VALUE_MAX * 2) + 3] = {‘\0‘}; //初始化属性数组。用于暂时存储拨号的属性变量 char ppp_local_ip[PROPERTY_VALUE_MAX] = {‘\0‘}; char ril_pppd_tty[PROPERTY_VALUE_MAX] = {‘\0‘}; char ppp_dns1[PROPERTY_VALUE_MAX] = {‘\0‘}; char ppp_dns2[PROPERTY_VALUE_MAX] = {‘\0‘}; char ppp_gw[PROPERTY_VALUE_MAX] = {‘\0‘}; char exit_code[PROPERTY_VALUE_MAX] = {‘\0‘}; int n = 1; RIL_Data_Call_Response_v6 *responses = alloca(n * sizeof(RIL_Data_Call_Response_v6)); //使用的是ipv6apn = ((const char **)data)[2]; //取传进来的接入点 apn /*ALOGD("jscese display in referenceAPN == ‘%s‘ \n",apn); apn ="3gnet"; */ ALOGD("[%s] jscese display in referenceAPN ‘%s‘ ", __func__, apn); #ifdef USE_TI_COMMANDS // Config for multislot class 10 (probably default anyway eh?
) err = at_send_command("AT%CPRIM=\"GMM\",\"CONFIG MULTISLOT_CLASS=< 10> \"", NULL); err = at_send_command("AT%DATA=https://www.songbingjia.com/android/2,/"UART\",1,,\"SER\",\"UART\",0", NULL); #endif /* USE_TI_COMMANDS */int fd, qmistatus; size_t cur = 0; size_t len; ssize_t written, rlen; char status[32] = {0}; int retry = 10; const char *pdp_type; ALOGD("requesting data connection to APN ‘%s‘", apn); pdp_type = "IP"; // jscese add for dialasprintf(& cmd, "AT+CGDCONT=1,\"%s\",\"%s\",,0,0", pdp_type, apn); //FIXME check for error here err = at_send_command(cmd, NULL); //发送接入点的AT指令 free(cmd); #if 0 // Set required QoS params to default err = at_send_command("AT+CGQREQ=1", NULL); // Set minimum QoS params to default err = at_send_command("AT+CGQMIN=1", NULL); // packet-domain event reporting err = at_send_command("AT+CGEREP=1,0", NULL); // Hangup anything that‘s happening there now err = at_send_command("AT+CGACT=1,0", NULL); #endif // Start data on PDP context 1 if (strcmp(apn, "3gnet") == 0) { ALOGD("jscese display in referenceis 3gnet \n"); err = at_send_command("ATD*99***1#", & p_response); //这个就是联通3G上网须要拨的号码 ATD*99***1# 获取连接} else if (strcmp(apn, "ctnet") == 0) { ALOGD("jscese display in referenceis ctnet \n"); err = at_send_command("ATD#777", & p_response); }if (err < 0 || p_response-> success == 0) { goto error; } at_response_free(p_response); sleep(1); //Wait for the modem to finishproperty_set("net.ppp1.local-ip", ""); property_set("net.gprs.ppp-exit", ""); property_set("ctl.start", "pppd_gprs"); //假设上面的拨号AT指令成功返回，这里就启用之前定义好的一个pppd service 调用脚本去拨号获取IP 等网络參数// Dialup sleep(3); /*jscese add try 5 times to get ip*/ int iRetry = 5; while (iRetry > 0) { property_get("net.gprs.ppp-exit", exit_code, ""); if (strcmp(exit_code, "0") != 0) { ALOGE("PPPd exit with code %s", exit_code); iRetry = 0; break; }ALOGI("Waiting For Property"); if (wait_for_property("net.ppp1.local-ip", NULL, 10) < 0) //监測 ip 地址的属性值。这个值我放在 pppd拨号脚本里面来进行设置，假设成功这里就能监測到 { ALOGE("[%s]: wait for IP from ppp link at %d\n", __func__, iRetry); } else { ALOGI("[%s]: got IP from ppp link\r\n", __func__); break; } iRetry--; }if (iRetry < = 0) { ALOGE("[%s]: fail to get IP\r\n", __func__); goto error; }/*if (wait_for_property("net.ppp1.local-ip", NULL, 10) < 0) { ALOGE("Timeout waiting net.ppp1.local-ip - giving up!\n"); goto error; }*/property_get("net.ppp1.local-ip", ppp_local_ip, NULL); property_get("net.ppp1.dns1", ppp_dns1, NULL); property_get("net.ppp1.dns2", ppp_dns2, NULL); property_get("net.ppp1.gw", ppp_gw, NULL); sprintf(ppp_dnses, "%s %s", ppp_dns1, ppp_dns2); ALOGI("Got net.ppp1.local-ip: %s\n", ppp_local_ip); responses[0].status = 0; responses[0].suggestedRetryTime = -1; responses[0].cid = 1; responses[0].active = 2; responses[0].type = "PPP"; responses[0].ifname = PPP_TTY_PATH; responses[0].addresses = ppp_local_ip; responses[0].dnses = ppp_dnses; responses[0].gateways = ppp_gw; //通过获取到的网络属性设置这个responses 提供给上层RIL_onRequestComplete(t, RIL_E_SUCCESS, responses, n * sizeof(RIL_Data_Call_Response_v6)); return; error: RIL_onRequestComplete(t, RIL_E_GENERIC_FAILURE, NULL, 0); at_response_free(p_response); }

二.pppd
在上面 requestSetupDataCall 中启动一个服务来调用pppd拨号，先在init.rc中加入：

#jscese add for usb_switch service when 3G dongle add for serialservice ril-daemon /system/bin/rild -l /system/lib/libreference-ril.so -- -d /dev/ttyUSB2 class main socket rild stream 660 root radio socket rild-debug stream 660 radio system user root group radio cache inet misc audio logservice pppd_gprs /system/etc/ppp/init.gprs-pppd /dev/ttyUSB0 user root group radio cache inet misc disabled oneshot ## end

上面的服务是用来开机启动rild的，载入libreference-ril动态库，
而且指定了通信port为串口 -d /dev/ttyUSB2，另外还有 -s 代表是socket设备 -p 代表回环接口

以下的就是pppd拨号的脚本服务了，用来启动拨号脚本，而且指定数据port.

这个pppd_gprs 服务须要设置权限。由于我是在reference-ril里面通过属性启动的在/system/core/init/property_service.c中加入例如以下：

struct { const char *service; unsigned int uid; unsigned int gid; } control_perms[] = { { "dumpstate",AID_SHELL, AID_LOG }, { "ril-daemon",AID_RADIO, AID_RADIO }, /*jscese add for pppd 3G*/ { "pppd_gprs",AID_RADIO, AID_LOG }, /*end*/ {NULL, 0, 0 } };

struct { const char *prefix; unsigned int uid; unsigned int gid; } property_perms[] = {.../*jscese addpppd for 3G*/ { "net.ppp1.",AID_RADIO,0 }, /*end*/{ NULL, 0, 0 } };

设置用到的net.ppp1.* 的权限。

【Android——4.2 - 3G移植之路之 reference-ril .pppd 拨号上网】init.gprs-pppd 设置运行权限，/system/core/include/private/android_filesystem_config.h中：

static struct fs_path_config android_files[] = {.../*jscese add for pppd */ { 00777, AID_ROOT,AID_SHELL,"system/etc/init.gprs-pppd" }, /*end*/...}

init.gprs-pppd：
贴出拨号脚本

#!/system/bin/sh PPPD_PID= USER=`/system/bin/getprop net.gprs.user` PASSWORD=`/system/bin/getprop net.gprs.password` /system/bin/setprop "net.gprs.ppp-exit" "" /system/bin/pppd $1 115200 linkname datakey unit 1 crtscts usepeerdns noauth defaultroute noipdefault ipcp-accept-local ipcp-accept-remote ipcp-max-failure 30 lcp-echo-interval 5 lcp-echo-failure 30 modem dump debug kdebug 8PPPD_EXIT=$? PPPD_PID=$! /system/bin/log -t pppd "pppd exited with $PPPD_EXIT" /system/bin/setprop "net.gprs.ppp-exit" "$PPPD_EXIT"

另外在这个拨号脚本同文件夹下 /system/etc/ppp/ 须要设置和注销ip等參数的脚本。一个在拨号成功时调用。一个在断开网络时调用：
ip-up-datakey：

#!/system/bin/sh case $1 in ppp1) /android/bin/iptables --flush; /android/bin/iptables --table nat --flush; /android/bin/iptables --delete-chain; /android/bin/iptables --table nat --append POSTROUTING --out-interface ppp0 -j MASQUERADE; /android/bin/iptables --append FORWARD --in-interface ppp1 -j ACCEPT; echo 0 > /proc/sys/net/ipv4/ip_forward; echo 1 > /proc/sys/net/ipv4/ip_forward; ; ; ppp0) /system/bin/setprop "net.interfaces.defaultroute" "ppp1"; ; ; esac /system/bin/setprop "net.ppp1.dns1" "$DNS1" /system/bin/setprop "net.ppp1.dns2" "$DNS2" /system/bin/setprop "net.ppp1.local-ip" "$IPLOCAL" /system/bin/setprop "net.ppp1.remote-ip" "$IPREMOTE" /system/bin/setprop "net.ppp1.gw" "$IPREMOTE" /system/bin/setprop "net.ppp1.if" "$IFNAME"

ip-down-datakey：

#!/system/bin/sh case $1 in ppp1) echo 0 > /proc/sys/net/ipv4/ip_forward; ; ; esac /system/bin/setprop "net.ppp1.dns1" "" /system/bin/setprop "net.ppp1.dns2" "" /system/bin/setprop "net.ppp1.local-ip" "" /system/bin/setprop "net.ppp1.remote-ip" "" /system/bin/setprop "net.ppp1.gw" "" /system/bin/setprop "net.ppp1.if" ""

贴张联通apn为 3gnet 的拨号log：