www.nico.schottelius.org/software/cinit/browse_source/cinit-0.0.7/client/exec_svc.c
Nico Schottelius 423ba10303 import cinit from unix.schottelius.org
Signed-off-by: Nico Schottelius <nico@ikn.schottelius.org>
2009-09-16 12:53:45 +02:00

246 lines
5.3 KiB
C

/*
* (c) 2005 Nico Schottelius (nico-linux at schottelius.org)
* run_svc
* part of cinit
*/
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "cinit.h"
/***********************************************************************
* exec_svc: exec service abspath C_ON or C_OFF
*/
pid_t exec_svc(char *abspath, int on)
{
pid_t pid;
int tmp;
char *p, pathtmp[PATH_MAX];
char *sbuf = NULL, **nargv = NULL, **nenv = NULL;
int fd, argc;
struct stat buf;
pid = fork();
if( pid == -1 ) {
perror("fork");
return 0;
}
/***** PARENT ******/
if(pid > 0) {
waitpid(pid,&tmp,0);
if( WIFEXITED(tmp) ) {
if( ! WEXITSTATUS(tmp) ) {
return pid;
}
}
D_PRINTF("EXEC SVC FEHLGESCHLAGEN");
return 0;
}
/*********** CHILD EXECUTION ***********/
strcpy(pathtmp,abspath);
strcat(pathtmp,"/");
if(on) {
strcat(pathtmp,C_ON);
} else {
strcat(pathtmp,C_OFF);
}
D_PRINTF(pathtmp);
/* readlink retrieves real name, if it is a symlink */
if ( (tmp = readlink(pathtmp,pathtmp,PATH_MAX) ) == -1) {
/* nothing there? fine, exit */
if(errno == ENOENT) {
_exit(0);
} else if (errno != EINVAL) {
perror("readlink");
_exit(1);
}
/* restore original name, file is not a link */
strcpy(pathtmp,abspath);
strcat(pathtmp,"/");
if(on) {
strcat(pathtmp,C_ON);
} else {
strcat(pathtmp,C_OFF);
}
tmp = strlen(pathtmp);
} else {
/* add '\0', readlink forgets it */
pathtmp[tmp] = '\0';
}
tmp++; /* the byte to add to memory for \0 */
/********** build argv0 ********/
nargv = (char **) malloc( sizeof(char *) );
if(nargv == NULL) _exit(1);
*nargv = (char *) malloc( tmp );
if(*nargv == NULL) _exit(1);
strcpy(*nargv,pathtmp);
/********************** read params *********************/
strcpy(pathtmp,abspath);
strcat(pathtmp,"/");
if(on) {
strcat(pathtmp,C_ONARG);
} else {
strcat(pathtmp,C_OFFARG);
}
/* open params file */
if( !stat(pathtmp,&buf) ) {
fd = open(pathtmp,O_RDONLY);
if(fd == -1) {
perror("open");
_exit(1);
}
argc = 0;
/* most likely one round */
while ( (tmp = read(fd,pathtmp,PATH_MAX) ) != 0 ) {
if(tmp == -1) {
perror("read");
_exit(1);
}
sbuf = realloc(sbuf,argc + tmp + 1);
strncpy(&sbuf[argc],pathtmp,tmp);
argc += tmp;
}
close(fd);
if(argc)
sbuf[argc] = '\0'; /* terminate string */
} else {
sbuf = NULL;
}
/************** build string **************/
/* The idea is to reuse the allocated memory. We'll simply
* replace the \n with \0 and set a char* to it.
* We'll lose the last byte (the initial \0), but we
* don't care, as we die some seconds later with execv() */
argc = 1; /* argv0 */
while( sbuf != NULL) {
p = strchr(sbuf,'\n');
nargv = realloc(nargv, sizeof(char *) * (argc + 1));
if(nargv == NULL) {
LOG("realloc failed");
_exit(1);
}
nargv[argc] = sbuf;
*p = '\0';
if( *(p+1) == '\0') {
sbuf = NULL;
} else {
sbuf = p+1;
}
argc++;
}
/************ close argv list **************/
nargv = realloc(nargv, sizeof(char *) * (argc + 1)); /* 1: NULL-pointer */
if(nargv == NULL) {
LOG("realloc failed");
_exit(1);
}
nargv[argc] = NULL; /* terminate argv list */
/********************** read environment *********************/
strcpy(pathtmp,abspath);
strcat(pathtmp,SLASH);
if(on) {
strcat(pathtmp,C_ONENV);
} else {
strcat(pathtmp,C_OFFENV);
}
argc = 0;
sbuf = NULL;
if( !stat(pathtmp,&buf) ) {
fd = open(pathtmp,O_RDONLY);
/* if a file exists, failing to open it is an error */
if(fd == -1) {
perror("open");
_exit(1);
}
while ( (tmp = read(fd,pathtmp,PATH_MAX) ) != 0 ) {
if(tmp == -1) {
perror("read");
_exit(1);
}
sbuf = realloc(sbuf,argc + tmp + 1);
strncpy(&sbuf[argc],pathtmp,tmp);
argc += tmp;
}
close(fd);
if(argc)
sbuf[argc] = '\0'; /* terminate string */
}
/************** build environment string **************/
argc = 0;
while( sbuf != NULL ) {
p = strchr(sbuf,'\n');
nenv = realloc(nenv, sizeof(char *) * (argc + 1));
if(nenv == NULL) {
LOG("realloc failed");
_exit(1);
}
nenv[argc] = sbuf;
*p = '\0';
if( *(p+1) == '\0') {
sbuf = NULL;
} else {
sbuf = p+1;
}
argc++;
}
/************ close env list **************/
nenv = realloc(nenv, sizeof(char *) * (argc + 1));
if(nenv == NULL) {
LOG(MSG_ERR_ALLOC);
_exit(1);
}
nenv[argc] = NULL;
/****************** EXECUTE ********************/
execve(nargv[0],nargv,nenv);
/* we should never reach this block */
perror(MSG_ERR_EXECVE);
_exit(1);
}