Some refactoring

6 files changed, 214 insertions, 77 deletions

diff --git a/src/main.c b/src/main.c
index 5831c1a..26bd354 100644
--- a/src/main.c
+++ b/src/main.c
@@ -76,42 +76,92 @@ struct prog_params parse_args(int argc, char* argv[])
 void handle_connection(int _socket, struct sockaddr_in _addr, int argc, char* argv[])
 {
 	pid_t pid = fork();
-	if( pid > 0 )
-	{
+	if( pid != 0 ) {
 		close(_socket);
 		return;
 	}
-	else if ( pid < 0 )
+
+	int in[2];
+	int out[2];
+
+	//1: write, 0: read
+	if(pipe(in) == -1)
+		return;
+	
+	if(pipe(out) == -1)
+		return;
+	
+	pid = fork_run(in[0], out[1], out[1], argc, argv);
+	if (pid < 0)
 		return;
 
-	//This is here for later
-	//This should handle a premature closed socket from client to not create unused processes
-	pid = fork();
-	if(pid > 0)
-	{
-		close(_socket);
-		//Instead of waiting for pid, check if process is running AND socket is still open
-		wait(0);
-		exit(0);
-	}
-	else if(pid < 0)
-		exit(1);
+	/*pid = fork();
 	
-	//Redirect STDIO to socket
-	dup2(_socket, STDIN_FILENO);
-	dup2(_socket, STDOUT_FILENO);
-	dup2(_socket, STDERR_FILENO);
+	if(pid == 0) {//child
+		close (in[1]);
+		close (out[0]);
+
+		dup2 (in[0],  STDIN_FILENO);
+		dup2 (out[1], STDOUT_FILENO);
+		dup2 (out[1], STDERR_FILENO);
 
-	char* arv[argc + 1];
+		char* arv[argc + 1];
 
-	for(int i = 0; i < argc; i++)
-		arv[i] = argv[i];
+		for(int i = 0; i < argc; i++)
+			arv[i] = argv[i];
 
-	arv[argc] = NULL;
+		arv[argc] = NULL;
 
-	execv(argv[0], arv);
+		execv(argv[0], arv);
+
+		printf("EXEC ERROR %i: %s\r\n", errno, strerror(errno));
+		exit(1);
+	}
+	else if (pid < 0) {
+		return;
+	}*/
+
+	const int buffsize = 128;
+	char buff[ buffsize ];
+
+	//close unused pipes
+	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 = _socket;
+	fds[1].events = POLLIN;
+
+	printf("Forked with PID %i\n", pid);
+
+	while(1)
+	{
+		int ret = poll (fds, 2, 100);
+		if ( fds[0].revents & POLLIN ) {
+			const int cnt = read (out[0], buff, buffsize);
+			if(try_write(_socket, buff, cnt, 100)) {
+				printf("Consecutive write errors while writing to socket.\n");
+				break;
+			}
+		}
+		if ( fds[1].revents & POLLIN ) {
+			const int cnt = read (_socket, buff, buffsize);
+			if(try_write(in[1], buff, cnt, 100)) {
+				printf("Consecutive write errors while writing to STDIN.\n");
+				break;
+			}
+		}
+
+		//TODO check socket active check. though somewhat handled by try_write()
+
+		if(kill(pid,0)) //Check if child is still alive, if not return.
+			break;
+	}
 
-	PRINT_ERROR("EXEC failed");
+	printf("Connection closed.\n");
 
 	close(_socket);
 	exit(1);
diff --git a/src/main.h b/src/main.h
index a599ae2..7a6153e 100644
--- a/src/main.h
+++ b/src/main.h
@@ -5,6 +5,8 @@
  * License: MIT
 */
 
+#pragma once
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -18,6 +20,8 @@
 #include <signal.h>
 #include <arpa/inet.h>
 
+#include "misc.h"
+
 #define _DEF_MAX_BACKLOG 	20
 #define _DEF_PORT 		23
 #define _DEF_IP			0
diff --git a/src/misc.c b/src/misc.c
new file mode 100644
index 0000000..c2803a6
--- /dev/null
+++ b/src/misc.c
@@ -0,0 +1,57 @@
+/*
+ * misc.c
+ * (c) 2019, Jonas Gunz, jonasgunz.de
+ * <Description>
+ * <License>
+*/
+
+#include "misc.h"
+
+pid_t fork_run(int _stdin, int _stdout, int _stderr, int argc, char* argv[])
+{
+	pid_t pid = fork();
+	
+	if(pid == 0) {//child
+		dup2 (_stdin,  STDIN_FILENO);
+		dup2 (_stdout, STDOUT_FILENO);
+		dup2 (_stderr, STDERR_FILENO);
+
+		char* arv[argc + 1];
+
+		for(int i = 0; i < argc; i++)
+			arv[i] = argv[i];
+
+		arv[argc] = NULL;
+
+		execv(argv[0], arv);
+
+		printf("EXEC ERROR %i: %s\r\n", errno, strerror(errno));
+		exit(1);
+	}
+	else {
+		return pid;
+	}
+}
+
+
+int try_write(int _fd, char *_buff, int _size, int _retry)
+{
+	if( _size <= 0)
+		return 0;
+
+	int written = 0;
+	int cntr = 0;
+
+	while (written != _size) {
+		int ret = write ( _fd, _buff + written, _size - written);
+		
+		if(ret < 0)
+			return 1;
+		else
+			written += ret; 
+
+		if(++cntr > _retry)
+			return 1;
+	}
+	return 0;
+}
diff --git a/src/misc.h b/src/misc.h
new file mode 100644
index 0000000..49a3384
--- /dev/null
+++ b/src/misc.h
@@ -0,0 +1,18 @@
+/*
+ * misc.h
+ * (c) 2019, Jonas Gunz, jonasgunz.de
+ * <Description>
+ * <License>
+*/
+
+#pragma once
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+int try_write(int _fd, char *_buff, int _size, int _retry);
+
+pid_t fork_run(int _stdin, int _stdout, int _stderr, int argc, char* argv[]);
diff --git a/src/modem.c b/src/modem.c
index a5644a7..0776bed 100644
--- a/src/modem.c
+++ b/src/modem.c
@@ -24,7 +24,7 @@ int modem_accept_wait(int fd)
 	modem_command(fd, _AT_MUTE, 1000);
 	modem_command(fd, _AT_RESET_ON_DTR, 1000);
 
-#ifdef _MODEM_WAIT_RING //DONT wait for ring
+#ifdef _MODEM_WAIT_RING
 	while ( 1 ) { //wait for RING
 		ret = poll(&fds, 1, 2000); //poll in 2s interval
 		usleep(5000);
@@ -44,7 +44,7 @@ int modem_accept_wait(int fd)
 	cnt = 0;
 	while(1)
 	{
-		ret = poll(&fds, 1, 60000); //Connection timeout 1 minute
+		ret = poll(&fds, 1, timeout); //Connection timeout 1 minute
 		usleep(5000); //Wait for data
 		if(!ret)
 			break;
@@ -121,9 +121,9 @@ int modem_run(int fd, int argc, char* argv[])
 	if(pipe(out) == -1)
 		return 1;
 	
-	pid_t pid = fork();
+	pid_t pid = fork_run(in[0], out[1], out[1], argc, argv);//fork();
 	
-	if(pid == 0) {//child
+/*	if(pid == 0) {//child
 		close (in[1]);
 		close (out[0]);
 
@@ -142,60 +142,66 @@ int modem_run(int fd, int argc, char* argv[])
 
 		printf("EXEC ERROR %i: %s\r\n", errno, strerror(errno));
 		exit(1);
-	}
-	else if (pid < 0) {//error
+	}*/
+	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;
-
-		printf("Forked with PID %i\n", pid);
-
-		while(1)
-		{
-			int ret = poll (fds, 2, 100);
-			usleep(5000); //Wait for data to fully come in, helps prevent truncation of status returns which helps with parsing
-			if ( fds[0].revents & POLLIN ) {
-				int cnt = read (out[0], buff, buffsize);
-				if(cnt) {
-					//replace +++ to not trigger modem command mode
-					char *str = strstr(buff, "+++");
-					if(str)
-						str[1] = '*';
-
-					write(fd, buff, cnt);
+
+	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;
+
+	printf("Forked with PID %i\n", pid);
+
+	while(1)
+	{
+		int ret = poll (fds, 2, 100);
+		usleep(5000); //Wait for data to fully come in, helps prevent truncation of status returns which helps with parsing
+		if ( fds[0].revents & POLLIN ) {
+			int cnt = read (out[0], buff, buffsize);
+			if(cnt) {
+				//replace +++ to not trigger modem command mode
+				char *str = strstr(buff, "+++");
+				if(str)
+					str[1] = '*';
+
+				if(try_write(fd, buff, cnt, 100)) {
+					printf("Consecutive write errors while writing to serial device.\n");
+					break;
 				}
 			}
-			if ( fds[1].revents & POLLIN ) {
-				int cnt = read (fd, buff, buffsize);
-				if(cnt) {
-					//search for modem error message
-					char *str = strstr(buff, "NO CARRIER");
-					if(str){ //Exit if message found
-						kill(pid,SIGTERM);
-						break;
-					}
-					write(in[1], buff, cnt);
+		}
+		if ( fds[1].revents & POLLIN ) {
+			int cnt = read (fd, buff, buffsize);
+			if(cnt) {
+				//search for modem error message
+				char *str = strstr(buff, "NO CARRIER");
+				if(str){ //Exit if message found
+					kill(pid,SIGTERM);
+					break;
 				}
-			}
 
-			if(kill(pid,0)) //Check if child is still alive, if not return.
-				break;
+				if(try_write(in[1], buff, cnt, 100)) {
+					printf("Consecutive write errors while writing to STDIN.\n");
+					break;
+				}
+			}
 		}
 
-		printf("Connection closed.\n");
-		close(fd); //Auto closes connection
-		return 0;
+		if(kill(pid,0)) //Check if child is still alive, if not return.
+			break;
 	}
+
+	printf("Connection closed.\n");
+	close(fd); //Auto closes connection
+	return 0;
 }
diff --git a/src/modem.h b/src/modem.h
index 246018d..e5aea4e 100644
--- a/src/modem.h
+++ b/src/modem.h
@@ -11,10 +11,12 @@
 #include <signal.h>
 #include <errno.h>
 
+#include "misc.h"
+
 #define _AT "AT\r\n"
 #define _AT_ANSWER "ATA\r\n"
 #define _AT_ECHO_OFF "ATE0\r\n"
-#define _AT_ECHO_ON "ATE1\r\n\”"
+#define _AT_ECHO_ON "ATE1\r\n"
 #define _AT_HANGUP "ATH\r\n"
 #define _AT_CMD_MODE "+++\r\n"
 #define _AT_MUTE "ATM0\r\n"