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/*****************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* $Id$
*
* Little tool to raise the amount of maximum file descriptor and then run the
* given command line (using the hard-coded uid/gid).
*
*/
#include <stdio.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
#include <errno.h>
#include <string.h> /* for errno translation */
/* ulimiter
*
* Source code inspiration from:
* http://www.cs.wisc.edu/condor/condorg/linux_scalability.html
*/
#define UID 1000 /* the user who must run this */
#define GID 1000 /* group id to run the program as */
/* Number of open files to increase to */
#define NEW_MAX 10000
int main(int argc, char *argv[])
{
int ret;
struct rlimit rl;
char *brgv[20];
int brgc=argc-1;
int i;
for(i=1; i< argc; i++)
brgv[i-1]=argv[i];
brgv[i-1]=NULL; /* terminate the list */
if(getuid() != UID) {
fprintf(stderr, "Only uid %d is allowed to run this\n", UID);
return 1;
}
ret = getrlimit(RLIMIT_NOFILE, &rl);
if(ret != 0) {
fprintf(stderr, "Unable to read open file limit.\n"
"(getrlimit(RLIMIT_NOFILE, &rl) failed)\n"
"(%d, %s)", errno, strerror(errno));
return 1;
}
fprintf(stderr, "Limit was %d (max %d), setting to %d\n",
rl.rlim_cur, rl.rlim_max, NEW_MAX);
rl.rlim_cur = rl.rlim_max = NEW_MAX;
ret = setrlimit(RLIMIT_NOFILE, &rl);
if(ret != 0) {
fprintf(stderr, "Unable to set open file limit.\n"
"(setrlimit(RLIMIT_NOFILE, &rl) failed)\n"
"(%d, %s)", errno, strerror(errno));
return 1;
}
ret = getrlimit(RLIMIT_NOFILE, &rl);
if(ret != 0) {
fprintf(stderr, "Unable to read new open file limit.\n"
"(getrlimit(RLIMIT_NOFILE, &rl) failed)\n"
"(%d, %s)", errno, strerror(errno));
return 1;
}
if(rl.rlim_cur < NEW_MAX) {
fprintf(stderr, "Failed to set new open file limit.\n"
"Limit is %d, expected %d\n",
rl.rlim_cur, NEW_MAX);
return 1;
}
if(setgid(GID) != 0) {
fprintf(stderr, "setgid failed (%d, %s)\n", errno, strerror(errno));
return 1;
}
if(setuid(UID) != 0) {
fprintf(stderr, "setuid failed (%d, %s)\n", errno, strerror(errno));
return 1;
}
ret = execv(brgv[0], brgv);
fprintf(stderr, "execl returned, failure\n"
"returned %d, errno is %d (%s)\n",
ret, errno, strerror(errno));
return 1;
}
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