config.c - pub/scm/linux/kernel/git/dborkman/l2md - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (C) 2019 Daniel Borkmann <daniel@iogearbox.net> */

 #include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <string.h>
 #include <wordexp.h>
 #include <stdbool.h>

 #include <sys/resource.h>

 #include "l2md.h"

 enum {
 	STATE_NONE = 0,
 	STATE_GENERAL,
 	STATE_REPO,
 	STATE_MAX,
 };

 static void config_dump(struct config *cfg)
 {
 	struct config_repo *repo;
 	struct config_url *url;
 	uint32_t i, j;

 	if (!verbose_enabled)
 		return;

 	verbose("general.base = %s\n", cfg->general.base);
 	verbose("general.mode = %s\n", cfg->ops->name);
 	verbose("general.%s = %s\n", cfg->ops->name, cfg->general.out);
 	verbose("general.period = %u\n", cfg->general.period);

 	repo_for_each(cfg, repo, i) {
 		verbose("repos.%s.%s = %s\n", repo->name, cfg->ops->name, repo->out);
 		verbose("repos.%s.initial_import = %u\n", repo->name, repo->initial_import);
 		url_for_each(repo, url, j) {
 			verbose("repos.%s.url = %s\n", repo->name, url->path);
 			verbose("repos.%s.oid = %s\n", repo->name,
 				url->oid_known ? url->oid : "[unknown]");
 		}
 	}

 	verbose("oneshot = %d\n", cfg->oneshot);
 }

 static void config_probe_oids(struct config *cfg)
 {
 	struct config_repo *repo;
 	struct config_url *url;
 	char path[PATH_MAX];
 	uint32_t i, j;
 	int ret;

 	repo_for_each(cfg, repo, i) {
 		url_for_each(repo, url, j) {
 			repo_local_oid(cfg, repo, url, path, sizeof(path));
 			ret = xread_file(path, url->oid, sizeof(url->oid) - 1,
 					 false);
 			if (!ret)
 				url->oid_known = true;
 		}
 	}
 }

 static void config_set_basedir(struct config *cfg, const char *dir)
 {
 	wordexp_t p;

 	wordexp(dir, &p, 0);
 	dir = p.we_wordv[0];
 	strlcpy(cfg->general.base, dir, sizeof(cfg->general.base));
 	wordfree(&p);
 }

 static void config_set_ops(struct config *cfg, const struct mail_ops* ops)
 {
 	cfg->ops = ops;
 }

 static void config_check_ops(struct config *cfg, const struct mail_ops* ops)
 {
 	if (cfg->ops != ops)
 		panic("mode %s in [general] must match [repo *] mode %s\n",
 		      cfg->ops->name, ops->name);
 }

 static void config_set_mode(struct config *cfg, const char *mode)
 {
 	if (!strncmp(mode, "maildir", sizeof("maildir")))
 		config_set_ops(cfg, &ops_maildir);
 	else if (!strncmp(mode, "pipe", sizeof("pipe")))
 		config_set_ops(cfg, &ops_pipe);
 	else
 		panic("Unknown mode: %s!\n", mode);
 }

 static void config_set_out(struct config *cfg, const char *ctx, bool root)
 {
 	struct config_repo *repo = repo_last(cfg);
 	char *out = root ? cfg->general.out : repo->out;
 	wordexp_t p;

 	wordexp(ctx, &p, 0);
 	ctx = p.we_wordv[0];
 	strlcpy(out, ctx, sizeof(repo->out));
 	wordfree(&p);
 }

 static void config_set_initial_import(struct config *cfg, uint32_t limit)
 {
 	struct config_repo *repo = repo_last(cfg);

 	repo->initial_import = limit;
 	if (repo->initial_import > 0)
 		repo->limit = true;
 }

 static void config_set_repo_status(struct config *cfg, bool status)
 {
 	struct config_repo *repo = repo_last(cfg);

 	repo->sync_enabled = status;
 }

 static void config_new_url(struct config *cfg, const char *git_url)
 {
 	struct config_repo *repo = repo_last(cfg);
 	struct config_url *url;

 	repo->urls_num++;
 	repo->urls = xrealloc(repo->urls, sizeof(*repo->urls) *
 			      repo->urls_num);
 	url = url_last(repo);
 	memset(url, 0, sizeof(*url));
 	strlcpy(url->path, git_url, sizeof(url->path));
 }

 static void config_new_repo(struct config *cfg, const char *name)
 {
 	struct config_repo *repo;

 	cfg->repos_num++;
 	cfg->repos = xrealloc(cfg->repos, sizeof(*cfg->repos) *
 			      cfg->repos_num);
 	repo = repo_last(cfg);
 	memset(repo, 0, sizeof(*repo));
 	config_set_out(cfg, cfg->general.out, false);
 	config_set_repo_status(cfg, true);
 	strlcpy(repo->name, name, sizeof(repo->name));
 }

 static void config_set_defaults(struct config *cfg, const char *homedir)
 {
 	char path[PATH_MAX];

 	cfg->general.period = 60;

 	slprintf(path, sizeof(path), "%s/.l2md", homedir);
 	strlcpy(cfg->general.base, path, sizeof(cfg->general.base));

 	config_set_ops(cfg, &ops_maildir);
 	cfg->ops->set_defaults(cfg);
 }

 static void config_ulimits(void)
 {
 	struct rlimit limit;
 	int ret;

 	ret = getrlimit(RLIMIT_NOFILE, &limit);
 	if (ret < 0)
 		panic("Cannot retrieve rlimit!\n");

 	/* The git repos we're dealing with can have a lot of
 	 * pack files potentially, hence increase open file limit
 	 * to help libgit2's revwalk.
 	 *
 	 * If there is a better API supported by native libgit2
 	 * for doing repack, we should use that instead:
 	 *
 	 * https://github.com/libgit2/libgit2/issues/3247
 	 */
 	limit.rlim_cur = limit.rlim_max;

 	ret = setrlimit(RLIMIT_NOFILE, &limit);
 	if (ret < 0)
 		panic("Cannot set rlimit!\n");
 }

 void config_uninit(struct config *cfg)
 {
 	struct config_repo *repo;
 	uint32_t i;

 	repo_for_each(cfg, repo, i)
 		xfree(repo->urls);
 	xfree(cfg->repos);
 	xfree(cfg);
 }

 struct config *config_init(int argc, char **argv)
 {
 	const char *homedir = getenv("HOME");
 	char buff[1024], tmp[1024] = {};
 	char path[PATH_MAX];
 	bool seen[STATE_MAX] = {};
 	int state = STATE_NONE;
 	struct config *cfg;
 	FILE *fp;

 	if (argc > 1) {
 		if (argc == 2 && !strncmp(argv[1], "--verbose",
 					  sizeof("--verbose")))
 			verbose_enabled = true;
 		else
 			panic("Usage: %s [--verbose]\n", argv[0]);
 	}

 	if (!homedir)
 		panic("Cannot retrieve $HOME from env!\n");

 	slprintf(path, sizeof(path), "%s/.l2mdconfig", homedir);
 	fp = fopen(path, "r");
 	if (!fp)
 		panic("Cannot open config %s: %s\n", path, strerror(errno));

 	config_ulimits();

 	cfg = xzmalloc(sizeof(*cfg));
 	config_set_defaults(cfg, homedir);

 	while (fgets(buff, sizeof(buff), fp)) {
 		uint32_t val;

 		if (buff[0] == '#' || buff[0] == '\n')
 			continue;

 		seen[state] = true;
 		switch (state) {
 		case STATE_NONE:
 		state_next:
 			if (!strcmp(buff, "[general]\n")) {
 				state = STATE_GENERAL;
 			} else if (sscanf(buff, "[repo %1023[a-z0-9-]]\n",
 					  tmp) == 1) {
 				state = STATE_REPO;
 				config_new_repo(cfg, tmp);
 			} else {
 				panic("Cannot parse: '%s'\n", buff);
 			}
 			break;

 		case STATE_GENERAL:
 			if (seen[STATE_REPO]) {
 				panic("[general] config must be before [repo *] config\n");
 			} else if (sscanf(buff, "\tperiod = %u", &val) == 1) {
 				cfg->general.period = val;
 			} else if (sscanf(buff, "\tmode = %1023s", tmp) == 1) {
 				config_set_mode(cfg, tmp);
 			} else if (sscanf(buff, "\tmaildir = %1023s", tmp) == 1) {
 				config_set_ops(cfg, &ops_maildir);
 				config_set_out(cfg, tmp, true);
 			} else if (sscanf(buff, "\tpipe = %1023s", tmp) == 1) {
 				config_set_ops(cfg, &ops_pipe);
 				config_set_out(cfg, tmp, true);
 			} else if (sscanf(buff, "\tbase = %1023s", tmp) == 1) {
 				config_set_basedir(cfg, tmp);
 			} else if (sscanf(buff, "\toneshot = %u", &val) == 1) {
 				cfg->oneshot = val;
 			} else {
 				goto state_next;
 			}
 			break;

 		case STATE_REPO:
 			if (sscanf(buff, "\turl = %1023s", tmp) == 1) {
 				config_new_url(cfg, tmp);
 			} else if (sscanf(buff, "\tmaildir = %1023s", tmp) == 1) {
 				config_check_ops(cfg, &ops_maildir);
 				config_set_out(cfg, tmp, false);
 			} else if (sscanf(buff, "\tpipe = %1023s", tmp) == 1) {
 				config_check_ops(cfg, &ops_pipe);
 				config_set_out(cfg, tmp, false);
 			} else if (sscanf(buff, "\tinitial_import = %u", &val) == 1) {
 				config_set_initial_import(cfg, val);
 			} else if (sscanf(buff, "\tsync_enabled = %u", &val) == 1) {
 				config_set_repo_status(cfg, val);
 			} else {
 				goto state_next;
 			}
 			break;

 		default:
 			panic("Invalid parser state: %d\n", state);
 		};
 	}

 	fclose(fp);

 	config_probe_oids(cfg);
 	config_dump(cfg);

 	return cfg;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/* Copyright (C) 2019 Daniel Borkmann <daniel@iogearbox.net> */

	#include <stdio.h>
	#include <stdlib.h>
	#include <errno.h>
	#include <string.h>
	#include <wordexp.h>
	#include <stdbool.h>

	#include <sys/resource.h>

	#include "l2md.h"

	enum {
	STATE_NONE = 0,
	STATE_GENERAL,
	STATE_REPO,
	STATE_MAX,
	};

	static void config_dump(struct config *cfg)
	{
	struct config_repo *repo;
	struct config_url *url;
	uint32_t i, j;

	if (!verbose_enabled)
	return;

	verbose("general.base = %s\n", cfg->general.base);
	verbose("general.mode = %s\n", cfg->ops->name);
	verbose("general.%s = %s\n", cfg->ops->name, cfg->general.out);
	verbose("general.period = %u\n", cfg->general.period);

	repo_for_each(cfg, repo, i) {
	verbose("repos.%s.%s = %s\n", repo->name, cfg->ops->name, repo->out);
	verbose("repos.%s.initial_import = %u\n", repo->name, repo->initial_import);
	url_for_each(repo, url, j) {
	verbose("repos.%s.url = %s\n", repo->name, url->path);
	verbose("repos.%s.oid = %s\n", repo->name,
	url->oid_known ? url->oid : "[unknown]");
	}
	}

	verbose("oneshot = %d\n", cfg->oneshot);
	}

	static void config_probe_oids(struct config *cfg)
	{
	struct config_repo *repo;
	struct config_url *url;
	char path[PATH_MAX];
	uint32_t i, j;
	int ret;

	repo_for_each(cfg, repo, i) {
	url_for_each(repo, url, j) {
	repo_local_oid(cfg, repo, url, path, sizeof(path));
	ret = xread_file(path, url->oid, sizeof(url->oid) - 1,
	false);
	if (!ret)
	url->oid_known = true;
	}
	}
	}

	static void config_set_basedir(struct config cfg, const char dir)
	{
	wordexp_t p;

	wordexp(dir, &p, 0);
	dir = p.we_wordv[0];
	strlcpy(cfg->general.base, dir, sizeof(cfg->general.base));
	wordfree(&p);
	}

	static void config_set_ops(struct config cfg, const struct mail_ops ops)
	{
	cfg->ops = ops;
	}

	static void config_check_ops(struct config cfg, const struct mail_ops ops)
	{
	if (cfg->ops != ops)
	panic("mode %s in [general] must match [repo *] mode %s\n",
	cfg->ops->name, ops->name);
	}

	static void config_set_mode(struct config cfg, const char mode)
	{
	if (!strncmp(mode, "maildir", sizeof("maildir")))
	config_set_ops(cfg, &ops_maildir);
	else if (!strncmp(mode, "pipe", sizeof("pipe")))
	config_set_ops(cfg, &ops_pipe);
	else
	panic("Unknown mode: %s!\n", mode);
	}

	static void config_set_out(struct config cfg, const char ctx, bool root)
	{
	struct config_repo *repo = repo_last(cfg);
	char *out = root ? cfg->general.out : repo->out;
	wordexp_t p;

	wordexp(ctx, &p, 0);
	ctx = p.we_wordv[0];
	strlcpy(out, ctx, sizeof(repo->out));
	wordfree(&p);
	}

	static void config_set_initial_import(struct config *cfg, uint32_t limit)
	{
	struct config_repo *repo = repo_last(cfg);

	repo->initial_import = limit;
	if (repo->initial_import > 0)
	repo->limit = true;
	}

	static void config_set_repo_status(struct config *cfg, bool status)
	{
	struct config_repo *repo = repo_last(cfg);

	repo->sync_enabled = status;
	}

	static void config_new_url(struct config cfg, const char git_url)
	{
	struct config_repo *repo = repo_last(cfg);
	struct config_url *url;

	repo->urls_num++;
	repo->urls = xrealloc(repo->urls, sizeof(repo->urls)
	repo->urls_num);
	url = url_last(repo);
	memset(url, 0, sizeof(*url));
	strlcpy(url->path, git_url, sizeof(url->path));
	}

	static void config_new_repo(struct config cfg, const char name)
	{
	struct config_repo *repo;

	cfg->repos_num++;
	cfg->repos = xrealloc(cfg->repos, sizeof(cfg->repos)
	cfg->repos_num);
	repo = repo_last(cfg);
	memset(repo, 0, sizeof(*repo));
	config_set_out(cfg, cfg->general.out, false);
	config_set_repo_status(cfg, true);
	strlcpy(repo->name, name, sizeof(repo->name));
	}

	static void config_set_defaults(struct config cfg, const char homedir)
	{
	char path[PATH_MAX];

	cfg->general.period = 60;

	slprintf(path, sizeof(path), "%s/.l2md", homedir);
	strlcpy(cfg->general.base, path, sizeof(cfg->general.base));

	config_set_ops(cfg, &ops_maildir);
	cfg->ops->set_defaults(cfg);
	}

	static void config_ulimits(void)
	{
	struct rlimit limit;
	int ret;

	ret = getrlimit(RLIMIT_NOFILE, &limit);
	if (ret < 0)
	panic("Cannot retrieve rlimit!\n");

	/* The git repos we're dealing with can have a lot of
	* pack files potentially, hence increase open file limit
	* to help libgit2's revwalk.
	*
	* If there is a better API supported by native libgit2
	* for doing repack, we should use that instead:
	*
	* https://github.com/libgit2/libgit2/issues/3247
	*/
	limit.rlim_cur = limit.rlim_max;

	ret = setrlimit(RLIMIT_NOFILE, &limit);
	if (ret < 0)
	panic("Cannot set rlimit!\n");
	}

	void config_uninit(struct config *cfg)
	{
	struct config_repo *repo;
	uint32_t i;

	repo_for_each(cfg, repo, i)
	xfree(repo->urls);
	xfree(cfg->repos);
	xfree(cfg);
	}

	struct config config_init(int argc, char *argv)
	{
	const char *homedir = getenv("HOME");
	char buff[1024], tmp[1024] = {};
	char path[PATH_MAX];
	bool seen[STATE_MAX] = {};
	int state = STATE_NONE;
	struct config *cfg;
	FILE *fp;

	if (argc > 1) {
	if (argc == 2 && !strncmp(argv[1], "--verbose",
	sizeof("--verbose")))
	verbose_enabled = true;
	else
	panic("Usage: %s [--verbose]\n", argv[0]);
	}

	if (!homedir)
	panic("Cannot retrieve $HOME from env!\n");

	slprintf(path, sizeof(path), "%s/.l2mdconfig", homedir);
	fp = fopen(path, "r");
	if (!fp)
	panic("Cannot open config %s: %s\n", path, strerror(errno));

	config_ulimits();

	cfg = xzmalloc(sizeof(*cfg));
	config_set_defaults(cfg, homedir);

	while (fgets(buff, sizeof(buff), fp)) {
	uint32_t val;

	if (buff[0] == '#' \|\| buff[0] == '\n')
	continue;

	seen[state] = true;
	switch (state) {
	case STATE_NONE:
	state_next:
	if (!strcmp(buff, "[general]\n")) {
	state = STATE_GENERAL;
	} else if (sscanf(buff, "[repo %1023[a-z0-9-]]\n",
	tmp) == 1) {
	state = STATE_REPO;
	config_new_repo(cfg, tmp);
	} else {
	panic("Cannot parse: '%s'\n", buff);
	}
	break;

	case STATE_GENERAL:
	if (seen[STATE_REPO]) {
	panic("[general] config must be before [repo *] config\n");
	} else if (sscanf(buff, "\tperiod = %u", &val) == 1) {
	cfg->general.period = val;
	} else if (sscanf(buff, "\tmode = %1023s", tmp) == 1) {
	config_set_mode(cfg, tmp);
	} else if (sscanf(buff, "\tmaildir = %1023s", tmp) == 1) {
	config_set_ops(cfg, &ops_maildir);
	config_set_out(cfg, tmp, true);
	} else if (sscanf(buff, "\tpipe = %1023s", tmp) == 1) {
	config_set_ops(cfg, &ops_pipe);
	config_set_out(cfg, tmp, true);
	} else if (sscanf(buff, "\tbase = %1023s", tmp) == 1) {
	config_set_basedir(cfg, tmp);
	} else if (sscanf(buff, "\toneshot = %u", &val) == 1) {
	cfg->oneshot = val;
	} else {
	goto state_next;
	}
	break;

	case STATE_REPO:
	if (sscanf(buff, "\turl = %1023s", tmp) == 1) {
	config_new_url(cfg, tmp);
	} else if (sscanf(buff, "\tmaildir = %1023s", tmp) == 1) {
	config_check_ops(cfg, &ops_maildir);
	config_set_out(cfg, tmp, false);
	} else if (sscanf(buff, "\tpipe = %1023s", tmp) == 1) {
	config_check_ops(cfg, &ops_pipe);
	config_set_out(cfg, tmp, false);
	} else if (sscanf(buff, "\tinitial_import = %u", &val) == 1) {
	config_set_initial_import(cfg, val);
	} else if (sscanf(buff, "\tsync_enabled = %u", &val) == 1) {
	config_set_repo_status(cfg, val);
	} else {
	goto state_next;
	}
	break;

	default:
	panic("Invalid parser state: %d\n", state);
	};
	}

	fclose(fp);

	config_probe_oids(cfg);
	config_dump(cfg);

	return cfg;
	}