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// SPDX-FileCopyrightText: 2025 Markus Uhlin <maxxe@rpblc.net>
// SPDX-License-Identifier: ISC
#include <string>
#include <vector>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "addgroup.h"
#define SELF_TEST 0
struct group_info {
std::string name;
std::string password;
int gid;
std::string members;
group_info()
{
this->name.assign("");
this->password.assign("");
this->gid = 0;
this->members.assign("");
}
group_info(const char *p_name, const char *p_password, const int p_gid,
const char *p_members)
{
this->name.assign(p_name);
this->password.assign(p_password);
this->gid = p_gid;
this->members.assign(p_members);
}
};
static std::vector<group_info> groups;
static const int FIRST_SYSTEM_GID = 100;
static const int LAST_SYSTEM_GID = 999;
static bool
is_free_gid(const int gid)
{
for (auto it = groups.begin(); it != groups.end(); ++it) {
if ((*it).gid == gid)
return false;
}
return true;
}
static int
get_free_gid(void)
{
if (groups.empty())
return -1;
for (int gid = FIRST_SYSTEM_GID; gid <= LAST_SYSTEM_GID; gid++) {
if (is_free_gid(gid))
return gid;
}
return -1;
}
int
fics_addgroup(const char *name)
{
int fd;
int gid;
if (name == nullptr || strcmp(name, "") == 0)
return -1;
else if (group_exists(name))
return 0;
else if ((gid = get_free_gid()) == -1)
return -1;
fd = open("/etc/group", (O_RDWR|O_APPEND));
if (fd < 0)
return -1;
struct group_info group(name, "*", gid, "");
dprintf(fd, "%s:%s:%d:%s\n", group.name.c_str(), group.password.c_str(),
group.gid, group.members.c_str());
close(fd);
groups.push_back(group);
return 0;
}
bool
get_group_id(const char *name, int *gid)
{
if (name == nullptr || strcmp(name, "") == 0 || gid == nullptr ||
groups.empty()) {
if (gid)
*gid = 0;
return false;
}
for (auto it = groups.begin(); it != groups.end(); ++it) {
if (strcmp((*it).name.c_str(), name) == 0) {
*gid = (*it).gid;
return true;
}
}
*gid = 0;
return false;
}
bool
get_next_line_from_file(FILE *fp, char **line)
{
const int LINE_MAX_LEN = 2048;
if (fp == nullptr || line == nullptr)
errx(1, "%s: invalid argument", __func__);
if (*line) {
delete[] *line;
*line = nullptr;
}
*line = new char[LINE_MAX_LEN];
return (fgets(*line, LINE_MAX_LEN, fp) ? true : false);
}
bool
group_exists(const char *name)
{
if (name == nullptr || strcmp(name, "") == 0 || groups.empty())
return false;
for (auto it = groups.begin(); it != groups.end(); ++it) {
if (strcmp((*it).name.c_str(), name) == 0)
return true;
}
return false;
}
int
read_the_group_permissions_file(const char *path)
{
FILE *fp = nullptr;
bool read_ok = false;
char *line = nullptr;
const char *token[4];
const char delim[] = ":";
int gid = 0;
if (!groups.empty())
return 0;
if ((fp = fopen(path, "r")) == nullptr)
return -1;
while (get_next_line_from_file(fp, &line)) {
token[0] = strsep(&line, delim);
token[1] = strsep(&line, delim);
token[2] = strsep(&line, delim);
token[3] = strsep(&line, delim);
if (token[0] == nullptr ||
token[1] == nullptr ||
token[2] == nullptr ||
token[3] == nullptr) {
warnx("%s: too few tokens", __func__);
continue;
} else if (sscanf(token[2], "%d", &gid) != 1) {
warnx("%s: sscanf() error", __func__);
continue;
}
struct group_info group(token[0], token[1], gid, token[3]);
groups.push_back(group);
}
if (feof(fp))
read_ok = true;
fclose(fp);
delete[] line;
return (read_ok ? 0 : -1);
}
#if SELF_TEST
int
main(void)
{
if (read_the_group_permissions_file("/etc/group") == -1)
errx(1, "failed to read the group permissions file");
if (fics_addgroup("chess") == -1)
errx(1, "failed to add a group");
puts("ok");
return 0;
}
#endif
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