1/* ui-snapshot.c: generate snapshot of a commit
  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 "html.h"
 11#include "ui-shared.h"
 12
 13static int write_compressed_tar_archive(struct archiver_args *args,const char *filter)
 14{
 15	int rw[2];
 16	pid_t gzpid;
 17	int stdout2;
 18	int status;
 19	int rv;
 20
 21	stdout2 = chk_non_negative(dup(STDIN_FILENO), "Preserving STDOUT before compressing");
 22	chk_zero(pipe(rw), "Opening pipe from compressor subprocess");
 23	gzpid = chk_non_negative(fork(), "Forking compressor subprocess");
 24	if(gzpid==0) {
 25		/* child */
 26		chk_zero(close(rw[1]), "Closing write end of pipe in child");
 27		chk_zero(close(STDIN_FILENO), "Closing STDIN");
 28		chk_non_negative(dup2(rw[0],STDIN_FILENO), "Redirecting compressor input to stdin");
 29		execlp(filter,filter,NULL);
 30		_exit(-1);
 31	}
 32	/* parent */
 33	chk_zero(close(rw[0]), "Closing read end of pipe");
 34	chk_non_negative(dup2(rw[1],STDOUT_FILENO), "Redirecting output to compressor");
 35
 36	rv = write_tar_archive(args);
 37
 38	chk_zero(close(STDOUT_FILENO), "Closing STDOUT redirected to compressor");
 39	chk_non_negative(dup2(stdout2,STDOUT_FILENO), "Restoring uncompressed STDOUT");
 40	chk_zero(close(stdout2), "Closing uncompressed STDOUT");
 41	chk_zero(close(rw[1]), "Closing write end of pipe in parent");
 42	chk_positive(waitpid(gzpid,&status,0), "Waiting on compressor process");
 43	if(! ( WIFEXITED(status) && WEXITSTATUS(status)==0 ) )
 44		cgit_print_error("Failed to compress archive");
 45
 46	return rv;
 47}
 48
 49static int write_tar_gzip_archive(struct archiver_args *args)
 50{
 51	return write_compressed_tar_archive(args,"gzip");
 52}
 53
 54static int write_tar_bzip2_archive(struct archiver_args *args)
 55{
 56	return write_compressed_tar_archive(args,"bzip2");
 57}
 58
 59const struct cgit_snapshot_format cgit_snapshot_formats[] = {
 60	{ ".zip", "application/x-zip", write_zip_archive, 0x1 },
 61	{ ".tar.gz", "application/x-tar", write_tar_gzip_archive, 0x2 },
 62	{ ".tar.bz2", "application/x-tar", write_tar_bzip2_archive, 0x4 },
 63	{ ".tar", "application/x-tar", write_tar_archive, 0x8 },
 64	{}
 65};
 66
 67static const struct cgit_snapshot_format *get_format(const char *filename)
 68{
 69	const struct cgit_snapshot_format *fmt;
 70	int fl, sl;
 71
 72	fl = strlen(filename);
 73	for(fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
 74		sl = strlen(fmt->suffix);
 75		if (sl >= fl)
 76			continue;
 77		if (!strcmp(fmt->suffix, filename + fl - sl))
 78			return fmt;
 79	}
 80	return NULL;
 81}
 82
 83static int make_snapshot(const struct cgit_snapshot_format *format,
 84			 const char *hex, const char *prefix,
 85			 const char *filename)
 86{
 87	struct archiver_args args;
 88	struct commit *commit;
 89	unsigned char sha1[20];
 90
 91	if(get_sha1(hex, sha1)) {
 92		cgit_print_error(fmt("Bad object id: %s", hex));
 93		return 1;
 94	}
 95	commit = lookup_commit_reference(sha1);
 96	if(!commit) {
 97		cgit_print_error(fmt("Not a commit reference: %s", hex));
 98		return 1;
 99	}
100	memset(&args, 0, sizeof(args));
101	if (prefix) {
102		args.base = fmt("%s/", prefix);
103		args.baselen = strlen(prefix) + 1;
104	} else {
105		args.base = "";
106		args.baselen = 0;
107	}
108	args.tree = commit->tree;
109	args.time = commit->date;
110	ctx.page.mimetype = xstrdup(format->mimetype);
111	ctx.page.filename = xstrdup(filename);
112	cgit_print_http_headers(&ctx);
113	format->write_func(&args);
114	return 0;
115}
116
117/* Try to guess the requested revision from the requested snapshot name.
118 * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
119 * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
120 * Otherwise, if the snapshot name has a prefix matching the result from
121 * repo_basename(), we strip the basename and any following '-' and '_'
122 * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
123 * more. If this still isn't a valid commit object name, we check if pre-
124 * pending a 'v' to the remaining snapshot name ("0.7.2" -> "v0.7.2") gives
125 * us something valid.
126 */
127static const char *get_ref_from_filename(const char *url, const char *filename,
128					 const struct cgit_snapshot_format *format)
129{
130	const char *reponame;
131	unsigned char sha1[20];
132	char *snapshot;
133
134	snapshot = xstrdup(filename);
135	snapshot[strlen(snapshot) - strlen(format->suffix)] = '\0';
136	fprintf(stderr, "snapshot=%s\n", snapshot);
137
138	if (get_sha1(snapshot, sha1) == 0)
139		return snapshot;
140
141	reponame = cgit_repobasename(url);
142	fprintf(stderr, "reponame=%s\n", reponame);
143	if (prefixcmp(snapshot, reponame) == 0) {
144		snapshot += strlen(reponame);
145		while (snapshot && (*snapshot == '-' || *snapshot == '_'))
146			snapshot++;
147	}
148
149	if (get_sha1(snapshot, sha1) == 0)
150		return snapshot;
151
152	snapshot = fmt("v%s", snapshot);
153	if (get_sha1(snapshot, sha1) == 0)
154		return snapshot;
155
156	return NULL;
157}
158
159void cgit_print_snapshot(const char *head, const char *hex,
160			 const char *filename, int snapshots, int dwim)
161{
162	const struct cgit_snapshot_format* f;
163	char *prefix = NULL;
164
165	f = get_format(filename);
166	if (!f) {
167		ctx.page.mimetype = "text/html";
168		cgit_print_http_headers(&ctx);
169		cgit_print_docstart(&ctx);
170		cgit_print_pageheader(&ctx);
171		cgit_print_error(fmt("Unsupported snapshot format: %s", filename));
172		cgit_print_docend();
173		return;
174	}
175
176	if (!hex && dwim) {
177		hex = get_ref_from_filename(ctx.repo->url, filename, f);
178		if (hex == NULL) {
179			html_status(404, "Not found", 0);
180			return;
181		}
182		prefix = xstrdup(filename);
183		prefix[strlen(filename) - strlen(f->suffix)] = '\0';
184	}
185
186	if (!hex)
187		hex = head;
188
189	if (!prefix)
190		prefix = xstrdup(cgit_repobasename(ctx.repo->url));
191
192	make_snapshot(f, hex, prefix, filename);
193	free(prefix);
194}