#include <arpa/inet.h>
#include <strings.h>
#include <pthread.h>
-#include <sys/ipc.h>
-#include <sys/shm.h>
#include <sys/wait.h>
#include <sys/poll.h>
#include <string.h>
/*3. RESULTS*/
- if (pre_fork_system(socket, command) < 0)
+ if (fork_system(socket, command) < 0)
goto err;
/*4. WAIT FOR CLIENT TO CLOSE CONNECTION AND FINISH*/
-int pre_fork_system(int socket, unsigned char *command)
-{
- /*Required variables in order to share memory between processes*/
- key_t keyvalue;
- int idreturnstatus = -1;
- /*Store the return status from the process launched using system or execve*/
- /*Using shared memory between the child and parent process*/
- int *returnstatus = NULL;
-
- int returnValue = -1; /*Return value from this function can be caught by upper*/
- /*layers, NOK by default*/
-
- // TODO: stop using shared memory. There must be another way to do this.
- // See OpenJDK Fork Process, it uses a file descriptor.
-
- /*
- * 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
- * variable between this process and the child that is going to be created in the
- * fork_system method.
- * The goal is to store in this variable the return status code received from the
- * process launched with the system method by the child process, then the parent
- * process can retrieve that return status code and send it by TCP to the Java client.
- * There are not concurrency issues because the parent process will just try to read
- * this variable when the child process is dead, taking in that moment its last value
- * and sending it to the Java client.
- */
-
- /*the /bin/ls must exist otherwise this does not work... */
- keyvalue=ftok("/bin/ls", SHAREMEMKEY);
- if (keyvalue == -1) {
- syslog (LOG_ERR, "ftok failed: %m");
- goto end;
- }
-
- /*Attach shared memory*/
- if ((idreturnstatus=shmget(keyvalue,sizeof(int), 0660 | IPC_CREAT)) < 0) {
- syslog (LOG_ERR, "shmget failed: %m");
- goto end_release_mem;
- }
-
- returnstatus = (int *)shmat(idreturnstatus, (void *)0, 0);
- if ((*returnstatus)== -1) {
- syslog (LOG_ERR, "shmat failed: %m");
- goto end_release_mem;
- }
-
- /*After allocating and attaching shared memory we reach this code if everything went OK.*/
-
- returnValue = fork_system(socket, command, returnstatus);
-
-
-end_release_mem:
- if (returnstatus != NULL) {
- /*detach memory*/
- if (shmdt ((int *)returnstatus) < 0)
- syslog (LOG_ERR, "returnstatus shared variable shmdt failed: %m");
- }
-
- /*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:
- return returnValue;
-}
-int fork_system(int socket, unsigned char *command, int *returnstatus)
+int fork_system(int socket, unsigned char *command)
{
pid_t pid; /*Child or parent PID.*/
int out[2], err[2]; /*Store pipes file descriptors. Write ends attached to the stdout*/
struct pollfd polls[2]; /*pipes attached to the stdout and stderr streams.*/
int n; /*characters number from stdout and stderr*/
struct tcpforkhdr *header = (struct tcpforkhdr *)buf;
- int childreturnstatus;
+ /*Value by default*/
+ int childreturnstatus = -1;
int returnValue = 0; /*return value from this function can be caught by upper layers,*/
/*OK by default*/
- sigset_t unBlockMask; /*Used by the child process in order to unblock the SIGCHLD signal, which was blocked by the main process.*/
int pollReturn;
+ unsigned char *tokenized_command;
- /*Value by default*/
- (*returnstatus) = -1;
out[0] = out[1] = err[0] = err[1] = -1;
closeSafely (sockfd);
closeSafely (socket);
- /*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*/
- /* will be ignored. From man system(3)*/
- /*Attention: warning about signedness. I guess it does not hurt me.*/
- /*TODO: usar para el retorno de system una variable local mejor que la variable compartida????*/
- *returnstatus=system(command);
- if (WIFEXITED(returnstatus) == 1)
- (*returnstatus) = WEXITSTATUS(*returnstatus);
- else
- (*returnstatus) = -1;
- /*Going to zombie state, hopefully waitpid will catch it*/
- _exit(EXIT_SUCCESS);
+ /*string tokenizer*/
+ tokenized_command = strtok(command, " ");
+ /*TODO: I should use execve with setlocale and the environment.*/
+ HERE EXECV
+
}
else {
/*Parent process*/
waitpidReturn = TEMP_FAILURE_RETRY(waitpid(pid, &status, WNOHANG));
if(waitpidReturn > 0) {
/*Child is dead, we can finish the connection*/
+
/*First of all, we check the exit status of our child process*/
- /*In case of error send an error status to the remote calling process*/
- if (WIFEXITED(status) != 1)
- goto err;
+ if (WIFEXITED(status)) {
+ /* The child exited normally; get its exit code.*/
+ childreturnstatus = WEXITSTATUS(status);
+ }
+ else
+ /*In case of error send an error status to the remote calling process*/
+ childreturnstatus = -1;
break;
}
else if(waitpidReturn < 0) {
}
}
}
- /*Stuff just done by the parent process. The child process ends with exit*/
- /*Reaching this code when child ends in the expected way*/
- childreturnstatus = *returnstatus;
end:
bzero(buf,2000);
projects / JavaTCPFork / .git / commitdiff