diff options
Diffstat (limited to 'FICS/addgroup.cpp')
| -rw-r--r-- | FICS/addgroup.cpp | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/FICS/addgroup.cpp b/FICS/addgroup.cpp new file mode 100644 index 0000000..52c6639 --- /dev/null +++ b/FICS/addgroup.cpp @@ -0,0 +1,219 @@ +// 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; +} + +bool +is_valid_group_name(const char *name) +{ + const char legal_index[] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz" + "0123456789_-"; + const size_t name_min = 2; + const size_t name_max = 30; + + if (name == nullptr || strcmp(name, "") == 0) + return false; + else if (strlen(name) < name_min || strlen(name) > name_max) + return false; + for (const char *cp = name; *cp != '\0'; cp++) { + if (strchr(legal_index, *cp) == nullptr) + return false; + } + return true; +} + +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 |