su: simplify logic

Inline dologin, and simplify common code
This commit is contained in:
neeshy 2024-02-12 21:26:35 -05:00 committed by Roberto E. Vargas Caballero
parent a015607af0
commit 8f5a0c3236
1 changed files with 28 additions and 42 deletions

70
su.c
View File

@ -18,28 +18,6 @@ extern char **environ;
static int lflag = 0;
static int pflag = 0;
static int
dologin(struct passwd *pw)
{
char *shell = pw->pw_shell[0] == '\0' ? "/bin/sh" : pw->pw_shell;
char *term = getenv("TERM");
clearenv();
setenv("HOME", pw->pw_dir, 1);
setenv("SHELL", shell, 1);
setenv("USER", pw->pw_name, 1);
setenv("LOGNAME", pw->pw_name, 1);
setenv("TERM", term ? term : "linux", 1);
if (strcmp(pw->pw_name, "root") == 0)
setenv("PATH", ENV_SUPATH, 1);
else
setenv("PATH", ENV_PATH, 1);
if (chdir(pw->pw_dir) < 0)
eprintf("chdir %s:", pw->pw_dir);
execlp(shell, shell, "-l", NULL);
weprintf("execlp %s:", shell);
return (errno == ENOENT) ? 127 : 126;
}
static void
usage(void)
{
@ -50,9 +28,9 @@ int
main(int argc, char *argv[])
{
char *usr = "root", *pass;
char *shell;
char *shell, *term;
struct passwd *pw;
char *newargv[2];
char *newargv[3];
uid_t uid;
ARGBEGIN {
@ -66,12 +44,9 @@ main(int argc, char *argv[])
usage();
} ARGEND;
if (argc < 1)
;
else if (argc == 1)
usr = argv[0];
else
if (argc != 1)
usage();
usr = argv[0];
errno = 0;
pw = getpwnam(usr);
@ -98,13 +73,26 @@ main(int argc, char *argv[])
if (setuid(pw->pw_uid) < 0)
eprintf("setuid:");
shell = pw->pw_shell[0] == '\0' ? "/bin/sh" : pw->pw_shell;
if (lflag) {
return dologin(pw);
newargv[0] = shell;
newargv[1] = "-l";
newargv[2] = NULL;
term = getenv("TERM");
clearenv();
setenv("HOME", pw->pw_dir, 1);
setenv("SHELL", shell, 1);
setenv("USER", pw->pw_name, 1);
setenv("LOGNAME", pw->pw_name, 1);
setenv("TERM", term ? term : "linux", 1);
if (chdir(pw->pw_dir) < 0)
eprintf("chdir %s:", pw->pw_dir);
} else {
shell = pw->pw_shell[0] == '\0' ? "/bin/sh" : pw->pw_shell;
newargv[0] = shell;
newargv[1] = NULL;
if (!pflag) {
if (pflag) {
shell = getenv("SHELL");
} else {
setenv("HOME", pw->pw_dir, 1);
setenv("SHELL", shell, 1);
if (strcmp(pw->pw_name, "root") != 0) {
@ -112,14 +100,12 @@ main(int argc, char *argv[])
setenv("LOGNAME", pw->pw_name, 1);
}
}
if (strcmp(pw->pw_name, "root") == 0)
setenv("PATH", ENV_SUPATH, 1);
else
setenv("PATH", ENV_PATH, 1);
execve(pflag ? getenv("SHELL") : shell,
newargv, environ);
weprintf("execve %s:", shell);
return (errno == ENOENT) ? 127 : 126;
}
return 0;
}
if (strcmp(pw->pw_name, "root") == 0)
setenv("PATH", ENV_SUPATH, 1);
else
setenv("PATH", ENV_PATH, 1);
execve(shell, newargv, environ);
weprintf("execve %s:", shell);
return (errno == ENOENT) ? 127 : 126;
}