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added erroring functions

master
Alessandro Mauri 3 months ago
parent
commit
c1050a27f9
1 changed files with 33 additions and 27 deletions
  1. +33
    -27
      us.c

+ 33
- 27
us.c View File

@ -47,6 +47,8 @@
#define MAX_HASH 1024
static void *emalloc(size_t);
static char *estrdup(const char *);
static void usage(void);
static void die(const char *, ...);
static int perm_set(struct passwd *, struct group *);
@ -102,9 +104,11 @@ int main(int argc, char *argv[])
fprintf(stderr, "getpwid: %s\n", strerror(errno));
return errno;
}
char *my_name = strdup(my_pw->pw_name);
if (!my_name)
die("strdup:");
char *my_name = estrdup(my_pw->pw_name);
/* From now on most actions require root */
if (setuid(0) == -1)
die("setuid:");
/* Authenticate, we will be root from now on */
if (authenticate(my_pw->pw_uid, 0))
@ -128,22 +132,13 @@ int main(int argc, char *argv[])
int c_argc = argc - optind;
char **c_argv;
if (c_argc) {
c_argv = malloc(sizeof(char *) * (c_argc + 1));
if (!c_argv)
die("malloc:");
for (int i = 0; optind < argc; optind++, i++) {
c_argv[i] = strdup(argv[optind]);
if (!c_argv[i])
die("strdup:");
}
c_argv = emalloc(sizeof(char *) * (c_argc + 1));
for (int i = 0; optind < argc; optind++, i++)
c_argv[i] = estrdup(argv[optind]);
} else {
c_argc = 1;
c_argv = malloc(sizeof(char *) * (c_argc + 1));
if (!c_argv)
die("malloc:");
c_argv[0] = strdup(shell);
if (!c_argv[0])
die("strdup:");
c_argv = emalloc(sizeof(char *) * (c_argc + 1));
c_argv[0] = estrdup(shell);
}
c_argv[c_argc] = NULL;
@ -171,11 +166,8 @@ int main(int argc, char *argv[])
};
if (envflag) { /* clear env */
for (int i = 0; env_keep[i].name; i++) {
env_keep[i].value = strdup(getenv(env_keep[i].name));
if (!env_keep[i].value)
die("strdup:");
}
for (int i = 0; env_keep[i].name; i++)
env_keep[i].value = estrdup(getenv(env_keep[i].name));
environ = NULL; // in place of clearenv
}
@ -285,9 +277,6 @@ static int authenticate(uid_t uid, char ask)
char *p = pw->pw_passwd;
int tty_fd = STDOUT_FILENO;
// but we have to be root
if (setuid(0) == -1)
die("setreuid:");
if (!strcmp(p, "x") || *p == '*' || *p == '!') {
#if defined(__linux__)
// get exclusive access to shadow
@ -300,8 +289,6 @@ static int authenticate(uid_t uid, char ask)
hash_p = sp->sp_pwdp;
endspent();
ulckpwdf();
// if (setuid(uid) == -1)
// die("setreuid:");
#elif defined(__OpenBSD__)
// TODO: openbsd has getpwuid_passwd
struct passwd *op = getpwuid_shadow(uid);
@ -469,3 +456,22 @@ void die(const char *fmt, ...)
exit(errno ? errno : EXIT_FAILURE);
}
void *emalloc(size_t s)
{
if (!s || s == (size_t)-1)
die("bad malloc: invalid size");
void *p = malloc(s);
if (!p)
die("bad malloc:");
return p;
}
char *estrdup(const char *s)
{
if (!s)
die("bad strdup: cannot duplicate NULL pointer");
char *r = strdup(s);
if (!r)
die("bad strdup:");
return r;
}

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