int pvalue = PORT; /*TCP port*/
int qvalue = QUEUE; /*TCP listen queue*/
struct sigaction sa; /*sig actions values*/
-
-
- /*This process is intended to be used as a daemon, it sould be launched by the INIT process, because of that*/
+
+ /*This process is intended to be used as a daemon, it sould be launched by the INIT process, because of that*/
/*we are not forking it (INIT needs it)*/
if (daemonize(argv[0], LOG_SYSLOG, LOG_PID) < 0)
return 1;
int socket = -1; /*Open socket by the Java client*/
long timeout, utimeout; /*Timeout for reading data from client: secs and usecs*/
/*respectively*/
+ uint32_t commandLength = 0; /*Store the command length*/
+ char *command = NULL; /*The command sent by the client, to be executed by this process*/
char buffer[sizeof(uint32_t)]; /*This buffer is intended to store the data received from the client*/
- char *command = NULL; /*The command sent by the client, to be executed by this process*/
- uint32_t commandLength = 0; /*Store the command length*/
socket = (int) arg;
/* COMMAND_LENGTH: Java integer 4 bytes, BIG-ENDIAN (the same as network order) */
/* COMMAND: locale character set encoding */
/* RESULTS: locale character set encoding */
- /* */
- /* JAVA CLIENT: ------------ COMMAND_LENGTH -------> :SERVER */
- /* JAVA CLIENT: -------------- COMMAND ------------> :SERVER */
- /* JAVA CLIENT: <-------------- RESULTS ------------ :SERVER */
- /* JAVA CLIENT: <---------- CLOSE CONNECTION ------- :SERVER */
+ /* */
+ /* JAVA CLIENT: ------------ COMMAND_LENGTH -------> :SERVER */
+ /* JAVA CLIENT: -------------- COMMAND ------------> :SERVER */
+ /* JAVA CLIENT: <-------------- RESULTS ------------ :SERVER */
+ /* JAVA CLIENT: <---------- CLOSE CONNECTION ------- :SERVER */
/* */
/****************************************************************************************/
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, */
+ /*if received 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;
/*Using shared memory between the child and parent process*/
int *returnstatus = NULL;
- /*Required variables in order to share the semaphore between processes*/
- key_t keysemaphore;
- int idsemaphore = -1;
- sem_t *semaphore = NULL; /*Used as a barrier: the child process just can start after */
- /*sending the XML init code*/
int returnValue = -1; /*Return value from this function can be caught by upper*/
/*layers, NOK by default*/
-
-
- /*
- * 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: fork_system function)
- */
-
- /*the /bin/ls must exist otherwise this does not work... */
- keysemaphore=ftok("/bin/ls", SHAREMEMSEM);
- if (keysemaphore == -1) {
- syslog (LOG_ERR, "ftok failed: %m");
- goto end;
- }
-
- /*Attach shared memory*/
- if ((idsemaphore = shmget(keysemaphore,sizeof(sem_t), 0660 | IPC_CREAT)) < 0) {
- syslog (LOG_ERR, "semaphore initialization failed: %m");
- goto end_release_sem;
- }
-
- if ((semaphore = (sem_t *)shmat(idsemaphore, (void *)0, 0)) < 0) {
- goto end_release_sem;
- }
-
- if (sem_init(semaphore, 1, 1) < 0) {
- syslog (LOG_ERR, "semaphore initialization failed: %m");
- goto end_destroy_sem;
- }
-
- if (TEMP_FAILURE_RETRY(sem_wait(semaphore)) < 0) {
- syslog (LOG_ERR, "semaphore wait failed: %m");
- goto end_destroy_sem;
- }
-
-
-
/*
* Allocate shared memory for the return status code from the process which is
* going to be launched by the system function. We want to share the returnstatus
keyvalue=ftok("/bin/ls", SHAREMEMKEY);
if (keyvalue == -1) {
syslog (LOG_ERR, "ftok failed: %m");
- goto end_destroy_sem;
+ goto end;
}
/*Attach shared memory*/
/*After allocating and attaching shared memory we reach this code if everything went OK.*/
- returnValue = fork_system(socket, command, semaphore, returnstatus);
+ returnValue = fork_system(socket, command, returnstatus);
end_release_mem:
/*Mark the segment to be destroyed.*/
if (shmctl (idreturnstatus, IPC_RMID, (struct shmid_ds *)NULL) < 0 )
syslog (LOG_ERR, "returnstatus shared variable shmctl failed: %m");
-end_destroy_sem:
- if (sem_destroy(semaphore) <0)
- syslog (LOG_ERR, "semaphore destroy failed: %m");
-end_release_sem:
- /*after sem_destroy-> input/output parameter NULL?*/
- if (semaphore != NULL) {
- /*detach memory*/
- if (shmdt ((sem_t *)semaphore) < 0)
- syslog (LOG_ERR, "semaphore shmdt failed: %m");
- }
-
- /*Mark the segment to be destroyed.*/
- if (shmctl (idsemaphore, IPC_RMID, (struct shmid_ds *)NULL) < 0 )
- syslog (LOG_ERR, "semaphore shmctl failed: %m");
end:
return returnValue;
}
-int fork_system(int socket, char *command, sem_t *semaphore, int *returnstatus)
+int fork_system(int socket, char *command, int *returnstatus)
{
int pid; /*Child or parent PID.*/
int out[2], err[2]; /*Store pipes file descriptors. Write ends attached to the stdout*/
/*and stderr streams.*/
- char buf[2000]; /*Read data buffer.*/
+ char buf[2000]; /*Read data buffer. allignment(int) * 500.*/
char string[3000];
struct pollfd polls[2]; /*pipes attached to the stdout and stderr streams.*/
int n; /*characters number from stdout and stderr*/
+ struct tcpforkhdr header;
int childreturnstatus;
int returnValue = 0; /*return value from this function can be caught by upper layers,*/
/*OK by default*/
if (pid == 0) {
/*Child process*/
/*It has to launch another one using system or execve*/
- if ((TEMP_FAILURE_RETRY(dup2(out[1],1)) < 0) || (TEMP_FAILURE_RETRY(dup2(err[1],2)) < 0)) {
+ if ((TEMP_FAILURE_RETRY(dup2(out[1], 1)) < 0) || (TEMP_FAILURE_RETRY(dup2(err[1], 2)) < 0)) {
syslog (LOG_ERR, "child dup2 failed: %m");
/*Going to zombie state, hopefully waitpid will catch it*/
exit(-1);
}
- if (TEMP_FAILURE_RETRY(sem_wait(semaphore)) < 0) {
- syslog (LOG_ERR, "child semaphore wait failed: %m");
- /*Going to zombie state, hopefully waitpid will catch it*/
- exit(-1);
- }
/*TODO: I should use execve with setlocale and the environment instead of system.*/
/*During execution of the command, SIGCHLD will be blocked, and SIGINT and SIGQUIT*/
/*TODO: stop using XML. Next improvements: my own client/server protocol*/
sprintf(string,"<?xml version=\"1.0\"?><streams>");
- if (TEMP_FAILURE_RETRY(send(socket,string,strlen(string),0)) < 0) {
+ if (TEMP_FAILURE_RETRY(send(socket,string,strlen(string),0)) < 0)
syslog (LOG_INFO, "error while sending xml header: %m");
-
- if (kill(pid, SIGKILL /*should I use SIGTERM and my own handler?*/) < 0) {
- /*We are not sure if the child process will die. In this case, probably the child */
- /*process is going to be an orphan and its system process (if there is one) as well*/
- syslog (LOG_ERR, "error while killing child process: %m");
- goto err;
- }
-
- if (TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0)) < 0) {
- /*We are not sure if the child process is dead. In this case, probably the child */
- /*process is going to be an orphan and its system process (if there is one) as well*/
- syslog (LOG_ERR, "error while waiting for killed child process: %m");
- }
-
- /*In Java the client will get a XMLParser Exception.*/
- goto err;
- }
- /*Releasing barrier, the child process can keep running*/
- if (sem_post(semaphore) < 0 ) {
- /*if the child process launched the system command the child process will die */
- /*and the system process is going to be an orphan process... :( */
- syslog (LOG_ERR, "parent error releasing barrier: %m");
-
- if (kill(pid, SIGKILL /*should I use SIGTERM and my own handler?*/) < 0) {
- /*We are not sure if the child process will die. In this case, probably the child */
- /*process is going to be an orphan and its system process (if there is one) as well*/
- syslog (LOG_ERR, "error while killing child process: %m");
- goto err;
- }
-
- if (TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0)) < 0) {
- /*We are not sure if the child process is dead. In this case, probably the child */
- /*process is going to be an orphan and its system process (if there is one) as well*/
- syslog (LOG_ERR, "error while waiting for killed child process: %m");
- }
-
- /*In Java the client will get a XMLParser Exception.*/
- goto err;
- }
for (;;) {
- if(poll(polls,2,100)) {
+ if(poll(polls, 2, 100)) {
if(polls[0].revents && POLLIN) {
bzero(buf,2000);
bzero(string, sizeof(string));
- n=TEMP_FAILURE_RETRY(read(out[0],buf,1990));
+ n=TEMP_FAILURE_RETRY(read(out[0], &buf[1], 1999));
+ bzero(&header, sizeof(header));
+ //To network order, indeed it is the order used by Java (BIG ENDIAN). Anyway I am
+ //swapping the bytes because it is required if you want to write portable code and
+ //ENDIANNESS indepedent.
+ header.type = htonl(1);
+ header.type = htonl(n);
+ //I do not care about the ENDIANNESS and character set in the payload, I send bytes
+ //and the client application must know what it has to do with them.
+ //TODO: my own protocol to make the client independent of the ENDIANNESS and character set used
+ //by the machine running this server. See comments in the TCPForkDaemon.java code about this.
sprintf(string,"<out><![CDATA[%s]]></out>", buf);
if (TEMP_FAILURE_RETRY(send(socket,string,strlen(string),0)) < 0)
syslog (LOG_INFO, "error while sending stdout: %m");
projects / JavaTCPFork / .git / commitdiff