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#include <shadow.h>
#include <errno.h>
#include <limits.h>
#include <pthread.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include <bits/ensure.h>
#include <mlibc/debug.hpp>
/*
* The code in this file is largely based on or taken from musl.
* This includes:
* - xatol
* - __parsespent
* - cleanup
* - getspnam_r
* - getspnam
*/
#define NUM(n) ((n) == -1 ? 0 : -1), ((n) == -1 ? 0 : (n))
int putspent(const struct spwd *sp, FILE *f) {
auto str = [] (char *s) {
return ((s) ? (s) : "");
};
return fprintf(f, "%s:%s:%.*d:%.*d:%.*d:%.*d:%.*d:%.*d:%.*u\n",
str(sp->sp_namp), str(sp->sp_pwdp), NUM(sp->sp_lstchg),
NUM(sp->sp_min), NUM(sp->sp_max), NUM(sp->sp_warn),
NUM(sp->sp_inact), NUM(sp->sp_expire), NUM((int)sp->sp_flag)) < 0 ? -1 : 0;
}
#undef NUM
static long xatol(char **s) {
long x;
if(**s == ':' || **s == '\n') {
return -1;
}
for(x = 0; (unsigned int)**s - '0' < 10U; ++*s) {
x = 10 * x + (**s - '0');
}
return x;
}
static int __parsespent(char *s, struct spwd *sp) {
sp->sp_namp = s;
if(!(s = strchr(s, ':'))) {
return -1;
}
*s = 0;
sp->sp_pwdp = ++s;
if(!(s = strchr(s, ':'))) {
return -1;
}
*s = 0;
s++;
sp->sp_lstchg = xatol(&s);
if(*s != ':') {
return -1;
}
s++;
sp->sp_min = xatol(&s);
if(*s != ':') {
return -1;
}
s++;
sp->sp_max = xatol(&s);
if(*s != ':') {
return -1;
}
s++;
sp->sp_warn = xatol(&s);
if(*s != ':') {
return -1;
}
s++;
sp->sp_inact = xatol(&s);
if(*s != ':') {
return -1;
}
s++;
sp->sp_expire = xatol(&s);
if(*s != ':') {
return -1;
}
s++;
sp->sp_flag = xatol(&s);
if(*s != '\n') {
return -1;
}
return 0;
}
static void cleanup(void *p) {
fclose((FILE *)p);
}
int getspnam_r(const char *name, struct spwd *sp, char *buf, size_t size, struct spwd **res) {
char path[20 + NAME_MAX];
FILE *f = 0;
int rv = 0;
int fd;
size_t k, l = strlen(name);
int skip = 0;
int cs;
int orig_errno = errno;
*res = 0;
/* Disallow potentially-malicious user names */
if(*name=='.' || strchr(name, '/') || !l) {
return errno = EINVAL;
}
/* Buffer size must at least be able to hold name, plus some.. */
if(size < l + 100) {
return errno = ERANGE;
}
/* Protect against truncation */
if(snprintf(path, sizeof path, "/etc/tcb/%s/shadow", name) >= (int)sizeof path) {
return errno = EINVAL;
}
fd = open(path, O_RDONLY|O_NOFOLLOW|O_NONBLOCK|O_CLOEXEC);
if(fd >= 0) {
struct stat st = {};
errno = EINVAL;
if(fstat(fd, &st) || !S_ISREG(st.st_mode) || !(f = fdopen(fd, "rb"))) {
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
close(fd);
pthread_setcancelstate(cs, 0);
return errno;
}
} else {
if(errno != ENOENT && errno != ENOTDIR) {
return errno;
}
f = fopen("/etc/shadow", "rbe");
if(!f) {
if(errno != ENOENT && errno != ENOTDIR) {
return errno;
}
return 0;
}
}
pthread_cleanup_push(cleanup, f);
while(fgets(buf, size, f) && (k = strlen(buf)) > 0) {
if(skip || strncmp(name, buf, l) || buf[l] != ':') {
skip = buf[k - 1] != '\n';
continue;
}
if(buf[k - 1] != '\n') {
rv = ERANGE;
break;
}
if(__parsespent(buf, sp) < 0) {
continue;
}
*res = sp;
break;
}
pthread_cleanup_pop(1);
errno = rv ? rv : orig_errno;
return rv;
}
int lckpwdf(void) {
mlibc::infoLogger() << "mlibc: lckpwdf is unimplemented like musl" << frg::endlog;
return 0;
}
int ulckpwdf(void) {
mlibc::infoLogger() << "mlibc: ulckpwdf is unimplemented like musl" << frg::endlog;
return 0;
}
// Musl defines LINE_LIM to 256
#define LINE_LIM 256
struct spwd *getspnam(const char *name) {
static struct spwd sp;
static char *line;
struct spwd *res;
int e;
int orig_errno = errno;
if(!line) {
line = (char *)malloc(LINE_LIM);
}
if(!line) {
return 0;
}
e = getspnam_r(name, &sp, line, LINE_LIM, &res);
errno = e ? e : orig_errno;
return res;
}
struct spwd *fgetspent(FILE *) {
__ensure(!"Not implemented");
__builtin_unreachable();
}
void endspent(void) {
mlibc::infoLogger() << "mlibc: endspent is a stub" << frg::endlog;
}
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