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Add ability to execute command without help of /bin/su

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It is important, if the program closes stdout, but does not exit.
Then, qrexec_agent does not see EOF (because su still holds the
file descriptor).
This commit is contained in:
Rafal Wojtczuk 2011-03-10 13:08:06 +01:00
parent a7cc09071f
commit 8f90623661
1 changed files with 36 additions and 6 deletions
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42
qrexec/qrexec_agent.c
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@ -28,6 +28,8 @@
#include <sys/wait.h>
#include <fcntl.h>
#include <string.h>
#include <pwd.h>
#include <grp.h>
#include "qrexec.h"
#include "buffer.h"
#include "glue.h"
@ -66,18 +68,46 @@ void init()
peer_server_init(REXEC_PORT);
}
void no_colon_in_cmd()
{
fprintf(stderr,
"cmdline is supposed to be in user:command form\n");
exit(1);
}
void do_exec_directly(char *cmd)
{
struct passwd *pwd;
char *sep = index(cmd, ':');
if (!sep)
no_colon_in_cmd();
*sep = 0;
pwd = getpwnam(cmd);
if (!pwd) {
perror("getpwnam");
exit(1);
}
setgid(pwd->pw_gid);
initgroups(cmd, pwd->pw_gid);
setuid(pwd->pw_uid);
setenv("HOME", pwd->pw_dir, 1);
setenv("USER", cmd, 1);
execl(sep + 1, sep + 1, NULL);
perror("execl");
exit(1);
}
void do_exec(char *cmd)
{
char *sep = index(cmd, ':');
if (!sep) {
fprintf(stderr,
"cmdline is supposed to be in user:command form\n");
exit(1);
}
if (!sep)
no_colon_in_cmd();
*sep = 0;
signal(SIGCHLD, SIG_DFL);
signal(SIGPIPE, SIG_DFL);
if (!strcmp(cmd, "directly"))
do_exec_directly(sep + 1);
execl("/bin/su", "su", "-", cmd, "-c", sep + 1, NULL);
perror("execl");
exit(1);
@ -89,7 +119,7 @@ void handle_just_exec(int clid, int len)
int fdn, pid;
read_all_vchan_ext(buf, len);
switch (pid=fork()) {
switch (pid = fork()) {
case -1:
perror("fork");
exit(1);