Android pppd_gprs script Startup Process

The GPRS internet access process of Android:

1. Open the data service device corresponding to the module in the RIL layer, such as/dev/ttyusb3.

2. Send the at + cgdcont command to the data device to specify the corresponding APN and send dialing commands such as atdt * 98*1 #.

3. After the above at command returns OK, you can start the pppd_gprs script. Before starting, set the attributes of the APN, such as user, PWD, and device.

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1. Property_set ("net. GPRS. User", user );
2. Property_set ("net. GPRS. Password", PWD );
3. Property_set ("net. GPRS. device", device );
4. Property_set ("net. GPRS. PPP-Exit ","");
6. Property_set ("CTL. Start", "pppd_gprs ");

4, attribute setting process in my previous blog has a detailed description of http://blog.csdn.net/yinlijun2004/article/details/6981954

See the code of the void handle_property_set_fd (int fd) function in property_service.c.

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1. Switch (msg. cmd ){
2. Case prop_msg_setprop:
3. MSG. name [PROP_NAME_MAX-1] = 0;
4. MSG. value [PROP_VALUE_MAX-1] = 0;
6. If (memcmp (msg. Name, "CTL.", 4) = 0 ){
7. If (check_control_perms (msg. Value, Cr. uid, Cr. GID )){
8. Handle_control_message (char *) MSG. Name + 4, (char *) msg. value );
9. } Else {
10. Error ("sys_prop: Unable to % s service CTL [% s] uid: % d PID: % d \ n ",
11. MSG. Name + 4, MSG. Value, Cr. uid, Cr. PID );
12. }

Call the handle_control_message function of init. c Based on the attribute key value "CTL. Start ".

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1. Void handle_control_message (const char * MSG, const char * Arg)
2. {
3. If (! Strcmp (MSG, "Start ")){
4. Msg_start (ARG );
5. } Else if (! Strcmp (MSG, "stop ")){
6. Msg_stop (ARG );
7. } Else {
8. Error ("unknown control MSG '% s' \ n", MSG );
9. }
10. }

In msg_start, find the service named pppd_gprs. The service name is also the script name, and then start and modify the service, that is, run the pppd_gprs script.

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1. Static void msg_start (const char * name)
2. {
3. Struct Service * SVC;
4. Char * TMP = NULL;
5. Char * ARGs = NULL;
7. If (! Strchr (name ,':'))
8. SVC = service_find_by_name (name );
9. Else {
10. TMP = strdup (name );
11. ARGs = strchr (TMP ,':');
12. * ARGs = '\ 0 ';
13. ARGs ++;
15. SVC = service_find_by_name (TMP );
16. }
18. If (SVC ){
19. Service_start (SVC, argS );
20. } Else {
21. Error ("No such service '% s' \ n", name );
22. }
23. If (TMP)
24. Free (TMP );
25. }

5. The pppd_gprs service is defined in the initialization script init. XX. RC and parsed from parser. C to service_list.

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1. Service pppd_gprs/system/xbin/pppd_gprs
2. User Root
3. Group Root
4. Oneshot
5. Disabled

6. The pppd_gprs script reads the attributes of the configured APN and runs the pppd process.

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1. User = '/system/bin/getprop net. GPRS. user'
2. Password = '/system/bin/getprop net. GPRS. password'
3. Device = '/system/bin/getprop net. GPRS. devic'
4. /System/bin/setprop net. GPRS. PPP-Exit ""
5. /System/bin/pppd-Detach $ device 115200 noipdefault noauth debug novj usepeerdns noccp ipcp-no-addresses kdebug 4 defaultroute user $ User Password $ Password
6. /System/bin/setprop net. GPRS. PPP-exit $?
7. # Exit $?

7. After the pppd_gprs script is executed, the RIL layer reads/sys/class/NET/ppp0/operstate to monitor the status of data network data.

From: http://blog.csdn.net/yinlijun2004/article/details/7007046

The GPRS internet access process of Android:

1. Open the data service device corresponding to the module in the RIL layer, such as/dev/ttyusb3.

2. Send the at + cgdcont command to the data device to specify the corresponding APN and send dialing commands such as atdt * 98*1 #.

3. After the above at command returns OK, you can start the pppd_gprs script. Before starting, set the attributes of the APN, such as user, PWD, and device.

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1. Property_set ("net. GPRS. User", user );
2. Property_set ("net. GPRS. Password", PWD );
3. Property_set ("net. GPRS. device", device );
4. Property_set ("net. GPRS. PPP-Exit ","");
6. Property_set ("CTL. Start", "pppd_gprs ");

4, attribute setting process in my previous blog has a detailed description of http://blog.csdn.net/yinlijun2004/article/details/6981954

See the code of the void handle_property_set_fd (int fd) function in property_service.c.

View plain

1. Switch (msg. cmd ){
2. Case prop_msg_setprop:
3. MSG. name [PROP_NAME_MAX-1] = 0;
4. MSG. value [PROP_VALUE_MAX-1] = 0;
6. If (memcmp (msg. Name, "CTL.", 4) = 0 ){
7. If (check_control_perms (msg. Value, Cr. uid, Cr. GID )){
8. Handle_control_message (char *) MSG. Name + 4, (char *) msg. value );
9. } Else {
10. Error ("sys_prop: Unable to % s service CTL [% s] uid: % d PID: % d \ n ",
11. MSG. Name + 4, MSG. Value, Cr. uid, Cr. PID );
12. }

Call the handle_control_message function of init. c Based on the attribute key value "CTL. Start ".

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1. Void handle_control_message (const char * MSG, const char * Arg)
2. {
3. If (! Strcmp (MSG, "Start ")){
4. Msg_start (ARG );
5. } Else if (! Strcmp (MSG, "stop ")){
6. Msg_stop (ARG );
7. } Else {
8. Error ("unknown control MSG '% s' \ n", MSG );
9. }
10. }

In msg_start, find the service named pppd_gprs. The service name is also the script name, and then start and modify the service, that is, run the pppd_gprs script.

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1. Static void msg_start (const char * name)
2. {
3. Struct Service * SVC;
4. Char * TMP = NULL;
5. Char * ARGs = NULL;
7. If (! Strchr (name ,':'))
8. SVC = service_find_by_name (name );
9. Else {
10. TMP = strdup (name );
11. ARGs = strchr (TMP ,':');
12. * ARGs = '\ 0 ';
13. ARGs ++;
15. SVC = service_find_by_name (TMP );
16. }
18. If (SVC ){
19. Service_start (SVC, argS );
20. } Else {
21. Error ("No such service '% s' \ n", name );
22. }
23. If (TMP)
24. Free (TMP );
25. }

5. The pppd_gprs service is defined in the initialization script init. XX. RC and parsed from parser. C to service_list.

View plain

1. Service pppd_gprs/system/xbin/pppd_gprs
2. User Root
3. Group Root
4. Oneshot
5. Disabled

6. The pppd_gprs script reads the attributes of the configured APN and runs the pppd process.

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1. User = '/system/bin/getprop net. GPRS. user'
2. Password = '/system/bin/getprop net. GPRS. password'
3. Device = '/system/bin/getprop net. GPRS. devic'
4. /System/bin/setprop net. GPRS. PPP-Exit ""
5. /System/bin/pppd-Detach $ device 115200 noipdefault noauth debug novj usepeerdns noccp ipcp-no-addresses kdebug 4 defaultroute user $ User Password $ Password
6. /System/bin/setprop net. GPRS. PPP-exit $?
7. # Exit $?

7. After the pppd_gprs script is executed, the RIL layer reads/sys/class/NET/ppp0/operstate to monitor the status of data network data.

From: http://blog.csdn.net/yinlijun2004/article/details/7007046