1/* cgit.c: cgi for the git scm
  2 *
  3 * Copyright (C) 2006 Lars Hjemli
  4 *
  5 * Licensed under GNU General Public License v2
  6 *   (see COPYING for full license text)
  7 */
  8
  9#include "cgit.h"
 10#include "cmd.h"
 11#include "ui-shared.h"
 12
 13static int cgit_prepare_cache(struct cacheitem *item)
 14{
 15	if (!ctx.repo && ctx.qry.repo) {
 16		ctx.page.title = fmt("%s - %s", ctx.cfg.root_title,
 17				      "Bad request");
 18		cgit_print_http_headers(&ctx);
 19		cgit_print_docstart(&ctx);
 20		cgit_print_pageheader(&ctx);
 21		cgit_print_error(fmt("Unknown repo: %s", ctx.qry.repo));
 22		cgit_print_docend();
 23		return 0;
 24	}
 25
 26	if (!ctx.repo) {
 27		item->name = xstrdup(fmt("%s/index.html", ctx.cfg.cache_root));
 28		item->ttl = ctx.cfg.cache_root_ttl;
 29		return 1;
 30	}
 31
 32	if (!cgit_cmd) {
 33		item->name = xstrdup(fmt("%s/%s/index.%s.html", ctx.cfg.cache_root,
 34					 cache_safe_filename(ctx.repo->url),
 35					 cache_safe_filename(ctx.qry.raw)));
 36		item->ttl = ctx.cfg.cache_repo_ttl;
 37	} else {
 38		item->name = xstrdup(fmt("%s/%s/%s/%s.html", ctx.cfg.cache_root,
 39					 cache_safe_filename(ctx.repo->url),
 40					 ctx.qry.page,
 41					 cache_safe_filename(ctx.qry.raw)));
 42		if (ctx.qry.has_symref)
 43			item->ttl = ctx.cfg.cache_dynamic_ttl;
 44		else if (ctx.qry.has_sha1)
 45			item->ttl = ctx.cfg.cache_static_ttl;
 46		else
 47			item->ttl = ctx.cfg.cache_repo_ttl;
 48	}
 49	return 1;
 50}
 51
 52struct refmatch {
 53	char *req_ref;
 54	char *first_ref;
 55	int match;
 56};
 57
 58int find_current_ref(const char *refname, const unsigned char *sha1,
 59		     int flags, void *cb_data)
 60{
 61	struct refmatch *info;
 62
 63	info = (struct refmatch *)cb_data;
 64	if (!strcmp(refname, info->req_ref))
 65		info->match = 1;
 66	if (!info->first_ref)
 67		info->first_ref = xstrdup(refname);
 68	return info->match;
 69}
 70
 71char *find_default_branch(struct cgit_repo *repo)
 72{
 73	struct refmatch info;
 74
 75	info.req_ref = repo->defbranch;
 76	info.first_ref = NULL;
 77	info.match = 0;
 78	for_each_branch_ref(find_current_ref, &info);
 79	if (info.match)
 80		return info.req_ref;
 81	else
 82		return info.first_ref;
 83}
 84
 85static int prepare_repo_cmd(struct cgit_context *ctx)
 86{
 87	char *tmp;
 88	unsigned char sha1[20];
 89	int nongit = 0;
 90
 91	setenv("GIT_DIR", ctx->repo->path, 1);
 92	setup_git_directory_gently(&nongit);
 93	if (nongit) {
 94		ctx->page.title = fmt("%s - %s", ctx->cfg.root_title,
 95				      "config error");
 96		tmp = fmt("Not a git repository: '%s'", ctx->repo->path);
 97		ctx->repo = NULL;
 98		cgit_print_http_headers(ctx);
 99		cgit_print_docstart(ctx);
100		cgit_print_pageheader(ctx);
101		cgit_print_error(tmp);
102		cgit_print_docend();
103		return 1;
104	}
105	ctx->page.title = fmt("%s - %s", ctx->repo->name, ctx->repo->desc);
106
107	if (!ctx->qry.head) {
108		ctx->qry.head = xstrdup(find_default_branch(ctx->repo));
109		ctx->repo->defbranch = ctx->qry.head;
110	}
111
112	if (!ctx->qry.head) {
113		cgit_print_http_headers(ctx);
114		cgit_print_docstart(ctx);
115		cgit_print_pageheader(ctx);
116		cgit_print_error("Repository seems to be empty");
117		cgit_print_docend();
118		return 1;
119	}
120
121	if (get_sha1(ctx->qry.head, sha1)) {
122		tmp = xstrdup(ctx->qry.head);
123		ctx->qry.head = ctx->repo->defbranch;
124		cgit_print_http_headers(ctx);
125		cgit_print_docstart(ctx);
126		cgit_print_pageheader(ctx);
127		cgit_print_error(fmt("Invalid branch: %s", tmp));
128		cgit_print_docend();
129		return 1;
130	}
131	return 0;
132}
133
134static void process_request(struct cgit_context *ctx)
135{
136	struct cgit_cmd *cmd;
137
138	cmd = cgit_get_cmd(ctx);
139	if (!cmd) {
140		ctx->page.title = "cgit error";
141		ctx->repo = NULL;
142		cgit_print_http_headers(ctx);
143		cgit_print_docstart(ctx);
144		cgit_print_pageheader(ctx);
145		cgit_print_error("Invalid request");
146		cgit_print_docend();
147		return;
148	}
149
150	if (cmd->want_repo && prepare_repo_cmd(ctx))
151		return;
152
153	if (cmd->want_layout) {
154		cgit_print_http_headers(ctx);
155		cgit_print_docstart(ctx);
156		cgit_print_pageheader(ctx);
157	}
158
159	cmd->fn(ctx);
160
161	if (cmd->want_layout)
162		cgit_print_docend();
163}
164
165static long ttl_seconds(long ttl)
166{
167	if (ttl<0)
168		return 60 * 60 * 24 * 365;
169	else
170		return ttl * 60;
171}
172
173static void cgit_fill_cache(struct cacheitem *item, int use_cache)
174{
175	int stdout2;
176
177	if (use_cache) {
178		stdout2 = chk_positive(dup(STDOUT_FILENO),
179				       "Preserving STDOUT");
180		chk_zero(close(STDOUT_FILENO), "Closing STDOUT");
181		chk_positive(dup2(item->fd, STDOUT_FILENO), "Dup2(cachefile)");
182	}
183
184	ctx.page.modified = time(NULL);
185	ctx.page.expires = ctx.page.modified + ttl_seconds(item->ttl);
186	process_request(&ctx);
187
188	if (use_cache) {
189		chk_zero(close(STDOUT_FILENO), "Close redirected STDOUT");
190		chk_positive(dup2(stdout2, STDOUT_FILENO),
191			     "Restoring original STDOUT");
192		chk_zero(close(stdout2), "Closing temporary STDOUT");
193	}
194}
195
196static void cgit_check_cache(struct cacheitem *item)
197{
198	int i = 0;
199
200 top:
201	if (++i > ctx.cfg.max_lock_attempts) {
202		die("cgit_refresh_cache: unable to lock %s: %s",
203		    item->name, strerror(errno));
204	}
205	if (!cache_exist(item)) {
206		if (!cache_lock(item)) {
207			sleep(1);
208			goto top;
209		}
210		if (!cache_exist(item)) {
211			cgit_fill_cache(item, 1);
212			cache_unlock(item);
213		} else {
214			cache_cancel_lock(item);
215		}
216	} else if (cache_expired(item) && cache_lock(item)) {
217		if (cache_expired(item)) {
218			cgit_fill_cache(item, 1);
219			cache_unlock(item);
220		} else {
221			cache_cancel_lock(item);
222		}
223	}
224}
225
226static void cgit_print_cache(struct cacheitem *item)
227{
228	static char buf[4096];
229	ssize_t i;
230
231	int fd = open(item->name, O_RDONLY);
232	if (fd<0)
233		die("Unable to open cached file %s", item->name);
234
235	while((i=read(fd, buf, sizeof(buf))) > 0)
236		write(STDOUT_FILENO, buf, i);
237
238	close(fd);
239}
240
241static void cgit_parse_args(int argc, const char **argv)
242{
243	int i;
244
245	for (i = 1; i < argc; i++) {
246		if (!strncmp(argv[i], "--cache=", 8)) {
247			ctx.cfg.cache_root = xstrdup(argv[i]+8);
248		}
249		if (!strcmp(argv[i], "--nocache")) {
250			ctx.cfg.nocache = 1;
251		}
252		if (!strncmp(argv[i], "--query=", 8)) {
253			ctx.qry.raw = xstrdup(argv[i]+8);
254		}
255		if (!strncmp(argv[i], "--repo=", 7)) {
256			ctx.qry.repo = xstrdup(argv[i]+7);
257		}
258		if (!strncmp(argv[i], "--page=", 7)) {
259			ctx.qry.page = xstrdup(argv[i]+7);
260		}
261		if (!strncmp(argv[i], "--head=", 7)) {
262			ctx.qry.head = xstrdup(argv[i]+7);
263			ctx.qry.has_symref = 1;
264		}
265		if (!strncmp(argv[i], "--sha1=", 7)) {
266			ctx.qry.sha1 = xstrdup(argv[i]+7);
267			ctx.qry.has_sha1 = 1;
268		}
269		if (!strncmp(argv[i], "--ofs=", 6)) {
270			ctx.qry.ofs = atoi(argv[i]+6);
271		}
272	}
273}
274
275int main(int argc, const char **argv)
276{
277	struct cacheitem item;
278	const char *cgit_config_env = getenv("CGIT_CONFIG");
279
280	cgit_prepare_context(&ctx);
281	item.st.st_mtime = time(NULL);
282	cgit_repolist.length = 0;
283	cgit_repolist.count = 0;
284	cgit_repolist.repos = NULL;
285
286	cgit_read_config(cgit_config_env ? cgit_config_env : CGIT_CONFIG,
287			 cgit_global_config_cb);
288	if (getenv("SCRIPT_NAME"))
289		ctx.cfg.script_name = xstrdup(getenv("SCRIPT_NAME"));
290	if (getenv("QUERY_STRING"))
291		ctx.qry.raw = xstrdup(getenv("QUERY_STRING"));
292	cgit_parse_args(argc, argv);
293	cgit_parse_query(ctx.qry.raw, cgit_querystring_cb);
294	if (!cgit_prepare_cache(&item))
295		return 0;
296	if (ctx.cfg.nocache) {
297		cgit_fill_cache(&item, 0);
298	} else {
299		cgit_check_cache(&item);
300		cgit_print_cache(&item);
301	}
302	return 0;
303}