Added new files

1 files changed, 198 insertions, 0 deletions

diff --git a/FICS/addgroup.cpp b/FICS/addgroup.cpp
new file mode 100644
index 0000000..59547d0
--- /dev/null
+++ b/FICS/addgroup.cpp
@@ -0,0 +1,198 @@
+// 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