Make pw(8) showuser work the same with or without -R <path> for non-root

users.  Without -R, pw(8) uses getpwnam(3), which will open master.passwd
for the root user or passwd for non-root users.  With -R <path> pw(8) was
always opening <path>/master.passwd, which would fail for a non-root user,
then falsely claim the userid you're trying to show doesn't exist.

Now for a non-root user it opens <path>/passwd and zeroes out the 3 fields
that aren't available in the passwd file, which duplicates the behavior of
getpwnam(3).  The net effect is that the showuser output is identical
whether using -R or not.
This commit is contained in:
Ian Lepore 2018-07-22 23:41:40 +00:00
parent 38c0c78e50
commit 1a61d99330

View File

@ -39,10 +39,13 @@ static const char rcsid[] =
#include <string.h> #include <string.h>
#include <stdlib.h> #include <stdlib.h>
#include <err.h> #include <err.h>
#include <unistd.h>
#include "pwupd.h" #include "pwupd.h"
static FILE * pwd_fp = NULL; static FILE * pwd_fp = NULL;
static int pwd_scanflag;
static const char *pwd_filename;
void void
vendpwent(void) vendpwent(void)
@ -71,7 +74,18 @@ vnextpwent(char const *nam, uid_t uid, int doclose)
line = NULL; line = NULL;
linecap = 0; linecap = 0;
if (pwd_fp != NULL || (pwd_fp = fopen(getpwpath(_MASTERPASSWD), "r")) != NULL) { if (pwd_fp == NULL) {
if (geteuid() == 0) {
pwd_filename = _MASTERPASSWD;
pwd_scanflag = PWSCAN_MASTER;
} else {
pwd_filename = _PASSWD;
pwd_scanflag = 0;
}
pwd_fp = fopen(getpwpath(pwd_filename), "r");
}
if (pwd_fp != NULL) {
while ((linelen = getline(&line, &linecap, pwd_fp)) > 0) { while ((linelen = getline(&line, &linecap, pwd_fp)) > 0) {
/* Skip comments and empty lines */ /* Skip comments and empty lines */
if (*line == '\n' || *line == '#') if (*line == '\n' || *line == '#')
@ -79,10 +93,10 @@ vnextpwent(char const *nam, uid_t uid, int doclose)
/* trim latest \n */ /* trim latest \n */
if (line[linelen - 1 ] == '\n') if (line[linelen - 1 ] == '\n')
line[linelen - 1] = '\0'; line[linelen - 1] = '\0';
pw = pw_scan(line, PWSCAN_MASTER); pw = pw_scan(line, pwd_scanflag);
if (pw == NULL) if (pw == NULL)
errx(EXIT_FAILURE, "Invalid user entry in '%s':" errx(EXIT_FAILURE, "Invalid user entry in '%s':"
" '%s'", getpwpath(_MASTERPASSWD), line); " '%s'", getpwpath(pwd_filename), line);
if (uid != (uid_t)-1) { if (uid != (uid_t)-1) {
if (uid == pw->pw_uid) if (uid == pw->pw_uid)
break; break;
@ -99,6 +113,18 @@ vnextpwent(char const *nam, uid_t uid, int doclose)
} }
free(line); free(line);
/*
* If we read the non-master passwd, some fields may not have been
* populated. Clean them up so that the output looks the same as that
* generated using getpwnam() which also inits them to these values.
*/
if (!(pw->pw_fields & _PWF_CLASS))
pw->pw_class = "";
if (!(pw->pw_fields & _PWF_CHANGE))
pw->pw_change = 0;
if (!(pw->pw_fields & _PWF_EXPIRE))
pw->pw_expire = 0;
return (pw); return (pw);
} }