Android——4.2 - 3G移植之路之 reference-ril .pppd 拨号上网 (三)

       Android的RIL机制中的 reference-ril.c 即为厂商提供的驱动接口，这个驱动源码各个厂商都是有提供的，网上也有下载，我现在用的就是huawei wcdma的，最后编译成libreference-ril.so，关于这个接口驱动在RIL中所扮演的角色可参考 Android——RIL 机制源码分析

android 4.2自带pppd源码在/external/ppp/pppd中.同样，kernel中也是需要打开对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码分析里有详细分析，这里就只从拨号连接分析。

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，用于临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ipv6    apn = ((const char **)data)[2]; //取传进来的接入点 apn    /*    ALOGD("jscese display in reference  APN == '%s' \n",apn);     apn ="3gnet";*/    ALOGD("[%s] jscese display in reference  APN '%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=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 dial    asprintf(&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 reference  is 3gnet \n");        err = at_send_command("ATD*99***1#", &p_response);  //这个就是联通3G上网需要拨的号码 ATD*99***1# 获取连接    }    else if (strcmp(apn, "ctnet") == 0)    {        ALOGD("jscese display in reference  is 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 finish    property_set("net.ppp1.local-ip", "");    property_set("net.gprs.ppp-exit", "");    property_set("ctl.start", "pppd_gprs"); //如果上面的拨号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 等网络参数    // 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) //监测 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，如果成功这里就能监测到        {            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中添加：

 #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，加载libreference-ril动态库，

并且指定了通信端口为串口 -d /dev/ttyUSB2，另外还有 -s 代表是socket设备 -p 代表回环接口

下面的就是pppd拨号的脚本服务了，用来启动拨号脚本，并且指定数据端口.

这个pppd_gprs 服务需要设置权限，因为我是在reference-ril里面通过属性启动的 在/system/core/init/property_service.c中添加如下：

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 add  pppd for 3G*/    { "net.ppp1.",AID_RADIO,0 },/*end*/    { NULL, 0, 0 }};

设置用到的net.ppp1.* 的权限。

init.gprs-pppd 设置执行权限，/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目录下 /system/etc/ppp/ 需要设置和注销ip等参数的脚本，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/shcase $1 in    ppp1)        /android/bin/iptables --flush;        /android/bin/iptables --table nat --flush;        /android/bin/iptables --delete-chain;        /android/bin/iptables --table nat --append POSTROUTING --out-interface ppp0 -j MASQUERADE;        /android/bin/iptables --append FORWARD --in-interface ppp1 -j ACCEPT;        echo 0 > /proc/sys/net/ipv4/ip_forward;        echo 1 > /proc/sys/net/ipv4/ip_forward;        ;;    ppp0)    /system/bin/setprop "net.interfaces.defaultroute" "ppp1";    ;;esac /system/bin/setprop "net.ppp1.dns1" "$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/shcase $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：