freebsd-dev/lib/libutil/gr_util.c
Sean Farley 0b5e889911 Add four utility functions related to struct grp processing modeled in-part
after similar calls related to struct pwd in libutil/pw_util.c:
  - gr_equal()
    Perform a deep comparison of two struct grp's.  It does a thorough, yet
    unoptimized comparison of all the members regardless of order.

  - gr_make()
    Create a string (see group(5)) from a struct grp.

  - gr_dup()
    Duplicate a struct grp.  Returns a value that is a single contiguous
    block of memory.

  - gr_scan()
    Create a struct grp from a string (as produced by gr_make()).

MFC after:	3 weeks
2008-04-23 00:49:13 +00:00

235 lines
5.7 KiB
C

/*-
* Copyright (c) 2008 Sean C. Farley <scf@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer,
* without modification, immediately at the beginning of the file.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <grp.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libutil.h>
static const char GroupLineFormat[] = "%s:%s:%ju:";
/*
* Compares two struct group's.
*/
int
gr_equal(const struct group *gr1, const struct group *gr2)
{
bool found;
bool equal;
int gr1Ndx;
int gr2Ndx;
/* Check that the non-member information is the same. */
equal = strcmp(gr1->gr_name, gr2->gr_name) == 0 &&
strcmp(gr1->gr_passwd, gr2->gr_passwd) == 0 &&
gr1->gr_gid == gr2->gr_gid;
/* Check all members in both groups. */
if (equal) {
for (found = false, gr1Ndx = 0; gr1->gr_mem[gr1Ndx] != NULL;
gr1Ndx++) {
for (gr2Ndx = 0; gr2->gr_mem[gr2Ndx] != NULL; gr2Ndx++)
if (strcmp(gr1->gr_mem[gr1Ndx],
gr2->gr_mem[gr2Ndx]) == 0) {
found = true;
break;
}
if (! found) {
equal = false;
break;
}
}
/* Check that group2 does not have more members than group1. */
if (gr2->gr_mem[gr1Ndx] != NULL)
equal = false;
}
return (equal);
}
/*
* Make a group line out of a struct group.
*/
char *
gr_make(const struct group *gr)
{
char *line;
int ndx;
size_t lineSize;
/* Calculate the length of the group line. */
lineSize = snprintf(NULL, 0, GroupLineFormat, gr->gr_name,
gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1;
for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
lineSize += strlen(gr->gr_mem[ndx]) + 1;
if (ndx > 0)
lineSize--;
/* Create the group line and fill it. */
if ((line = malloc(lineSize)) == NULL)
return (NULL);
lineSize = snprintf(line, lineSize, GroupLineFormat, gr->gr_name,
gr->gr_passwd, (uintmax_t)gr->gr_gid);
for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
strcat(line, gr->gr_mem[ndx]);
if (gr->gr_mem[ndx + 1] != NULL)
strcat(line, ",");
}
return (line);
}
/*
* Duplicate a struct group.
*/
struct group *
gr_dup(const struct group *gr)
{
int ndx;
int numMem;
size_t len;
struct group *ngr;
/* Calculate size of group. */
len = sizeof(*gr) +
(gr->gr_name != NULL ? strlen(gr->gr_name) + 1 : 0) +
(gr->gr_passwd != NULL ? strlen(gr->gr_passwd) + 1 : 0);
numMem = 0;
if (gr->gr_mem != NULL) {
for (; gr->gr_mem[numMem] != NULL; numMem++)
len += strlen(gr->gr_mem[numMem]) + 1;
len += (numMem + 1) * sizeof(*(gr->gr_mem));
}
/* Create new group and copy old group into it. */
if ((ngr = calloc(1, len)) == NULL)
return (NULL);
len = sizeof(*ngr);
ngr->gr_gid = gr->gr_gid;
if (gr->gr_name != NULL) {
ngr->gr_name = (char *)ngr + len;
len += sprintf(ngr->gr_name, "%s", gr->gr_name) + 1;
}
if (gr->gr_passwd != NULL) {
ngr->gr_passwd = (char *)ngr + len;
len += sprintf(ngr->gr_passwd, "%s", gr->gr_passwd) + 1;
}
if (gr->gr_mem != NULL) {
ngr->gr_mem = (char **)((char *)ngr + len);
len += (numMem + 1) * sizeof(*(ngr->gr_mem));
for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
ngr->gr_mem[ndx] = (char *)ngr + len;
len += sprintf(ngr->gr_mem[ndx], "%s",
gr->gr_mem[ndx]) + 1;
}
ngr->gr_mem[ndx] = NULL;
}
return (ngr);
}
/*
* Scan a line and place it into a group structure.
*/
static bool
__gr_scan(char *line, struct group *gr)
{
char *loc;
int ndx;
/* Assign non-member information to structure. */
gr->gr_name = line;
if ((loc = strchr(line, ':')) == NULL)
return (false);
*loc = '\0';
gr->gr_passwd = loc + 1;
if (*(gr->gr_passwd) == ':')
*(gr->gr_passwd) = '\0';
else {
if ((loc = strchr(loc + 1, ':')) == NULL)
return (false);
*loc = '\0';
}
if (sscanf(loc + 1, "%u", &(gr->gr_gid)) != 1)
return (false);
/* Assign member information to structure. */
if ((loc = strchr(loc + 1, ':')) == NULL)
return (false);
line = loc + 1;
gr->gr_mem = NULL;
if (*line != '\0') {
ndx = 0;
do {
if ((gr->gr_mem = reallocf(gr->gr_mem,
sizeof(*(gr->gr_mem)) * (ndx + 1))) == NULL)
return (false);
gr->gr_mem[ndx] = strsep(&line, ",");
} while (gr->gr_mem[ndx++] != NULL);
}
return (true);
}
/*
* Create a struct group from a line.
*/
struct group *
gr_scan(const char *line)
{
char *lineCopy;
struct group *newGr;
struct group gr;
if ((lineCopy = strdup(line)) == NULL)
return (NULL);
if (!__gr_scan(lineCopy, &gr)) {
free(lineCopy);
return (NULL);
}
newGr = gr_dup(&gr);
free(lineCopy);
if (gr.gr_mem != NULL)
free(gr.gr_mem);
return (newGr);
}