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/*
* modem.c
* (c) 2019, Jonas Gunz, jonasgunz.de
* <Description>
* <License>
*/
#include "modem.h"
int modem_accept_wait(int fd)
{
if(!fd)
return 1;
char buff[128];
int ret; //for retturn values
struct pollfd fds; //poll struct
int cnt = 0; //read byte counter
fds.fd = fd;
fds.events = POLLIN;
write(fd, _AT_ECHO_OFF, strlen(_AT_ECHO_OFF) );
int ok = 0;
while(1) {
ret = poll(&fds, 1, 1000);
if (ret)
cnt = read(fd, buff, 128); //Dummy read from _AT_ECHO_OFF, should say OK
else
break;
if( strstr(buff, "OK") )
ok = 1;
}
if(! ok )
return 3;
printf("Modem OK\n");
while ( 1 ) { //wait for RING
ret = poll(&fds, 1, 2000); //poll in 2s interval
if(ret) {
cnt = read ( fd, buff, 128 );
if(strstr(buff, "RING"))
break;
}
}
printf("Modem RINGING\n");
write (fd, _AT_ANSWER, strlen(_AT_ANSWER)); //Accept incoming call
ret = poll(&fds, 1, 30000);
if(ret) {
cnt = read (fd, buff, 128);
if(strstr(buff, "CONNECT"))
return 0;
else
return 4;
}
return 5;
}
int modem_hang(int fd)
{
}
int modem_run(int fd, int argc, char* argv[])
{
int in[2];
int out[2];
//1: write, 0: read
if(pipe(in) == -1)
return 1;
if(pipe(out) == -1)
return 1;
pid_t pid = fork();
if(pid == 0) {//child
close (in[1]);
close (out[0]);
dup2 (in[0], STDIN_FILENO);
dup2 (out[1], STDOUT_FILENO);
printf("EXEC ERROR\n\n");
exit(0);
}
else if (pid < 0) {//error
return 2;
}
else {//parent
int buffsize = 128;
char buff[ buffsize ];
close (in[0]);
close (out[1]);
//setup poll to listen for input
struct pollfd fds[2];
fds[0].fd = out[0];
fds[0].events = POLLIN;
fds[1].fd = fd;
fds[1].events = POLLIN;
while(1)
{
int ret = poll (fds, 2, 100);
if ( fds[0].revents & POLLIN ) {
int cnt = read (out[0], buff, buffsize);
if(cnt) {
while(1) { //replace +++ to not trigger modem command mode
char *str = strstr(buff, "+++");
if(str)
str[1] = '*';
}
write(fd, buff, cnt);
}
}
if ( fds[1].revents & POLLIN ) {
int cnt = read (fd, buff, buffsize);
if(cnt) {
while(1) { //search for modem error message
char *str = strstr(buff, "NO CARRIER");
if(str) { //Exit if message found
return 0;
}
}
write(in[1], buff, cnt);
}
}
if(kill(pid,0)) //Check if child is still alive, if not return.
return 0;
}
}
}
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