{
struct timeval ptime; /*Timeout, secs and usecs*/
fd_set fd_read; /*Values for select function.*/
+ int ret; /*Store return value from select.*/
ptime.tv_sec = timeout;
ptime.tv_usec = utimeout;
FD_ZERO(&fd_read);
FD_SET(fd, &fd_read);
- return TEMP_FAILURE_RETRY(select(fd+1, &fd_read, NULL, NULL, &ptime));
+ ret = TEMP_FAILURE_RETRY(select(fd+1, &fd_read, NULL, NULL, &ptime));
+
+ if (ret == 0) {
+ syslog(LOG_INFO, "receiving timeout error");
+ return -1;
+ } else if (ret == -1) {
+ syslog(LOG_ERR, "receiving error: %m");
+ return -1;
+ }
+
+ return ret;
}
-int receive_from_socket (int socket, char *data, int len, long timeout, long utimeout)
+int readable (int socket, char *data, int len, int flags)
{
- int nData, iPos; /*Control variables.*/
- int ret; /*Store return value from select.*/
+ int received; /*Stores received data from socket*/
- nData = iPos = 0;
- do {
- ret = readable_timeout(socket, timeout, utimeout);
+ received = TEMP_FAILURE_RETRY(recv(socket, data, len, flags));
- if (ret == 0) {
- syslog(LOG_INFO, "receiving timeout error");
- return -1;
- } else if (ret == -1) {
- syslog(LOG_ERR, "receiving error: %m");
+ if (received < 0) {
+ if ((errno != EAGAIN) && (errno != EWOULDBLOCK)) {
+ syslog (LOG_ERR, "read TCP socket failed: %m");
return -1;
+ } else {
+ /*see spurious readiness man select(2) BUGS section*/
+ received = 0;
+ syslog (LOG_INFO, "read TCP socket spurious readiness");
}
+ } else if (received == 0) {
+ /*if nData is 0, client closed connection but we wanted to receive more data, this is an error */
+ syslog (LOG_ERR, "expected more data, closed connection from client");
+ return -1;
+ }
+
+ return received;
+}
- nData = TEMP_FAILURE_RETRY(recv(socket, &data[iPos], len, 0));
- if (nData < 0) {
- if ((errno != EAGAIN) && (errno != EWOULDBLOCK)) {
- syslog (LOG_ERR, "read TCP socket failed: %m");
- return -1;
- } else {
- /*see spurious readiness man select(2) BUGS section*/
- nData = 0;
- syslog (LOG_INFO, "read TCP socket spurious readiness");
- }
- } else if (nData == 0) {
- /*if nData is 0, client closed connection but we wanted to receive more data, this is an error */
- syslog (LOG_ERR, "expected more data from client");
+
+int receive_from_socket (int socket, char *data, int len, long timeout, long utimeout)
+{
+ int nData, iPos; /*Control variables.*/
+
+ nData = iPos = 0;
+ do {
+ if (readable_timeout(socket, timeout, utimeout) < 0)
+ return -1;
+
+ if ((nData = readable (socket, &data[iPos], len, 0)) < 0)
return -1;
- }
len -= nData;
iPos += nData;
/*Allocate shared memory because we can not use named semaphores*/
/*We are using this semaphore as a barrier, because we just want to start the child process when the parent process has sent*/
- /*the XML header (see: for_system function)*/
+ /*the XML header (see: fork_system function)*/
keysemaphore=ftok("/bin/ls", SHAREMEMSEM); /*the /bin/ls must exist otherwise this does not work... */
if (keysemaphore == -1) {
exit(-1);
}
+ /*TODO: I should use execve with setlocale instead of system.*/
+ /*During execution of the command, SIGCHLD will be blocked, and SIGINT and SIGQUIT*/
+ /* will be ignored. From man system(3)*/
*returnstatus=system(command);
if (WIFEXITED(returnstatus) == 1)
(*returnstatus) = WEXITSTATUS(*returnstatus);
/*It sends data to the Java client using a TCP connection.*/
polls[0].fd=out[0];
polls[1].fd=err[0];
- polls[0].events=POLLIN;
- polls[1].events=POLLIN;
+ polls[0].events = polls[1].events = POLLIN;
sprintf(string,"<?xml version=\"1.0\"?>");
send(socket,string,strlen(string),0);
sprintf(string,"<streams>");
/*Releasing barrier, the child process can keep running*/
if (sem_post(semaphore) < 0 ) {
syslog (LOG_ERR, "parent error releasing barrier: %m");
- /*TODO: May I kill a child process if it is already dead? I mean, */
- /* what could happen if the child process is dead? */
- /* Should I implement a SIGCHILD handler? */
- /*TODO: Should I have a SIGTERM handler in the child process? */
- kill(pid, SIGTERM);
- goto err;
+ /*TODO: SIGTERM and SIGCHLD by default are ignored (interactive bash) */
+ /*if the child process launched the system command the child process will die */
+ /*and the system process is going to be an orphan process... :( */
+ if (kill(pid, SIGKILL /*should I use SIGTERM and my own handler?*/) < 0) {
+ syslog (LOG_ERR, "error while killing child process: %m");
+ /*This is the worst that could happen, we are not sure if the child process is going to die */
+ /*in this case, probably the child process is going to be an orphan and its system process ass welll*/
+ /*goto err?*/
+ }
+ /*TODO: sigprocmask(SIG_BLOCK, SIGCHLD, NULL) at the beginning of this whole program */
+ /*from bash it makes a clone and this parent process inherits the bash signal handlers */
+ /*but not its signal masks. we want to block until child process is dead */
+ /*because of that we must block SIGCHLD.*/
+ waitpid(pid, NULL, 0);
+ /*goto err?*/;
}
while(1) {
if(poll(polls,2,100)) {
- if(polls[0].revents&&POLLIN) {
+ if(polls[0].revents && POLLIN) {
bzero(buf,2000);
n=read(out[0],buf,1990);
sprintf(string,"<out><![CDATA[");
send(socket,string,strlen(string),0);
}
- if(polls[1].revents&&POLLIN) {
+ if(polls[1].revents && POLLIN) {
bzero(buf,2000);
n=read(err[0],buf,1990);
sprintf(string,"<error><![CDATA[");
send(socket,string,strlen(string),0);
}
- if(!polls[0].revents&&POLLIN && !polls[1].revents&&POLLIN) {
+ if(!(polls[0].revents && POLLIN) && !(polls[1].revents && POLLIN)) {
syslog (LOG_ERR, "parent error polling pipes: %m");
- /*TODO: May I kill a child process if it is already dead? I mean, */
- /* what could happen if the child process is dead? */
- /* Should I implement a SIGCHILD handler? */
+ /*TODO: Should I implement a SIGCHILD handler? */
/*TODO: Should I have a SIGTERM handler in the child process? */
kill(pid, SIGTERM);
/*I want to send an error status to the remote calling process */
-/****************************************************************************************
-* This method is used by pthread_create *
-* *
-* INPUT PARAMETER: socket file descriptor *
-* RETURNS: void *
-****************************************************************************************/
+/****************************************************************************************/
+/* This method is used by pthread_create */
+/* */
+/* INPUT PARAMETER: socket file descriptor */
+/* RETURNS: void */
+/****************************************************************************************/
void *serverThread (void *arg);
-/****************************************************************************************
-* This method is used by pthread_create *
-* *
-* INPUT PARAMETER: socket file descriptor *
-* INPUT PARAMETER:
-* INPUT PARAMETER:
-* RETURNS: void *
-****************************************************************************************/
+/****************************************************************************************/
+/* This method is used by pthread_create */
+/* */
+/* INPUT PARAMETER: socket file descriptor */
+/* INPUT PARAMETER: */
+/* INPUT PARAMETER: */
+/* RETURNS: void */
+/****************************************************************************************/
int daemonize(const char *pname, int facility, int option);
-/****************************************************************************************
-* This method is used by pthread_create *
-* *
-* INPUT PARAMETER: socket file descriptor *
-* RETURNS: int *
-****************************************************************************************/
+/****************************************************************************************/
+/* This method is used by pthread_create */
+/* */
+/* INPUT PARAMETER: socket file descriptor */
+/* RETURNS: int */
+/****************************************************************************************/
int main_daemon (char *address, int port, int queue);
-/****************************************************************************************
-* This method is used by pthread_create *
-* *
-* INPUT PARAMETER: socket file descriptor *
-* RETURNS: void *
-****************************************************************************************/
+/****************************************************************************************/
+/* This method is used by pthread_create */
+/* */
+/* INPUT PARAMETER: socket file descriptor */
+/* RETURNS: void */
+/****************************************************************************************/
int fork_system(int socket, char *command, sem_t *semaphore, int *returnst);
-/****************************************************************************************
-* This method is used by pthread_create *
-* *
-* INPUT PARAMETER: socket file descriptor *
-* RETURNS: void *
-****************************************************************************************/
-int pre_fork_system(int socket, char *command);
-
+/****************************************************************************************/
+/* This method is used by pthread_create */
+/* */
+/* INPUT PARAMETER: socket file descriptor */
+/* RETURNS: void */
+/****************************************************************************************/
+int pre_fork_system(int socket, char *command);
-/****************************************************************************************
-* This method is used by pthread_create *
-* *
-* INPUT PARAMETER: socket file descriptor *
-* RETURNS: void *
-****************************************************************************************/
+/****************************************************************************************/
+/* This method is used by pthread_create */
+/* */
+/* INPUT PARAMETER: socket file descriptor */
+/* RETURNS: void */
+/****************************************************************************************/
void sigint_handler();
int required_sock_options (int socket);
+
+
+
int receive_from_socket (int socket, char *data, int len, long timeout, long utimeout);
+
+
+
int readable_timeout (int fd, long timeout, long utimeout);
+
+
+
+int readable (int socket, char *data, int len, int flags);
projects / JavaTCPFork / .git / commitdiff