Add support for cloning over http

This patch implements basic support for cloning over http, based on the
work on git-http-backend by Shawn O. Pearce.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

6 files changed, 140 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index e1436a3..78aad10 100644
--- a/Makefile
+++ b/Makefile
@@ -11,96 +11,97 @@ GIT_URL = http://www.kernel.org/pub/software/scm/git/git-$(GIT_VER).tar.bz2
 # Let the user override the above settings.
 #
 -include cgit.conf
 
 #
 # Define a way to invoke make in subdirs quietly, shamelessly ripped
 # from git.git
 #
 QUIET_SUBDIR0  = +$(MAKE) -C # space to separate -C and subdir
 QUIET_SUBDIR1  =
 
 ifneq ($(findstring $(MAKEFLAGS),w),w)
 PRINT_DIR = --no-print-directory
 else # "make -w"
 NO_SUBDIR = :
 endif
 
 ifndef V
 	QUIET_CC       = @echo '   ' CC $@;
 	QUIET_MM       = @echo '   ' MM $@;
 	QUIET_SUBDIR0  = +@subdir=
 	QUIET_SUBDIR1  = ;$(NO_SUBDIR) echo '   ' SUBDIR $$subdir; \
 			 $(MAKE) $(PRINT_DIR) -C $$subdir
 endif
 
 #
 # Define a pattern rule for automatic dependency building
 #
 %.d: %.c
 	$(QUIET_MM)$(CC) $(CFLAGS) -MM $< | sed -e 's/\($*\)\.o:/\1.o $@:/g' >$@
 
 #
 # Define a pattern rule for silent object building
 #
 %.o: %.c
 	$(QUIET_CC)$(CC) -o $*.o -c $(CFLAGS) $<
 
 
 EXTLIBS = git/libgit.a git/xdiff/lib.a -lz -lcrypto
 OBJECTS =
 OBJECTS += cache.o
 OBJECTS += cgit.o
 OBJECTS += cmd.o
 OBJECTS += configfile.o
 OBJECTS += html.o
 OBJECTS += parsing.o
 OBJECTS += shared.o
 OBJECTS += ui-blob.o
+OBJECTS += ui-clone.o
 OBJECTS += ui-commit.o
 OBJECTS += ui-diff.o
 OBJECTS += ui-log.o
 OBJECTS += ui-patch.o
 OBJECTS += ui-refs.o
 OBJECTS += ui-repolist.o
 OBJECTS += ui-shared.o
 OBJECTS += ui-snapshot.o
 OBJECTS += ui-summary.o
 OBJECTS += ui-tag.o
 OBJECTS += ui-tree.o
 
 ifdef NEEDS_LIBICONV
 	EXTLIBS += -liconv
 endif
 
 
 .PHONY: all git test install uninstall clean force-version get-git
 
 all: cgit
 
 VERSION: force-version
 	@./gen-version.sh "$(CGIT_VERSION)"
 -include VERSION
 
 
 CFLAGS += -g -Wall -Igit
 CFLAGS += -DSHA1_HEADER='$(SHA1_HEADER)'
 CFLAGS += -DCGIT_VERSION='"$(CGIT_VERSION)"'
 CFLAGS += -DCGIT_CONFIG='"$(CGIT_CONFIG)"'
 CFLAGS += -DCGIT_SCRIPT_NAME='"$(CGIT_SCRIPT_NAME)"'
 CFLAGS += -DCGIT_CACHE_ROOT='"$(CACHE_ROOT)"'
 
 
 cgit: $(OBJECTS) git/libgit.a git/xdiff/lib.a
 	$(QUIET_CC)$(CC) $(CFLAGS) -o cgit $(OBJECTS) $(EXTLIBS)
 
 cgit.o: VERSION
 
 -include $(OBJECTS:.o=.d)
 
 git/libgit.a: git
 	$(QUIET_SUBDIR0)git $(QUIET_SUBDIR1) libgit.a
 
 git/xdiff/lib.a: git
 	$(QUIET_SUBDIR0)git $(QUIET_SUBDIR1) xdiff/lib.a
 
 test: all
diff --git a/cmd.c b/cmd.c
index fe0ea8f..03e165c 100644
--- a/cmd.c
+++ b/cmd.c
@@ -1,132 +1,151 @@
 /* cmd.c: the cgit command dispatcher
  *
  * Copyright (C) 2008 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 #include "cmd.h"
 #include "cache.h"
 #include "ui-shared.h"
 #include "ui-blob.h"
+#include "ui-clone.h"
 #include "ui-commit.h"
 #include "ui-diff.h"
 #include "ui-log.h"
 #include "ui-patch.h"
 #include "ui-refs.h"
 #include "ui-repolist.h"
 #include "ui-snapshot.h"
 #include "ui-summary.h"
 #include "ui-tag.h"
 #include "ui-tree.h"
 
+static void HEAD_fn(struct cgit_context *ctx)
+{
+	cgit_clone_head(ctx);
+}
+
 static void about_fn(struct cgit_context *ctx)
 {
 	if (ctx->repo)
 		cgit_print_repo_readme();
 	else
 		cgit_print_site_readme();
 }
 
 static void blob_fn(struct cgit_context *ctx)
 {
 	cgit_print_blob(ctx->qry.sha1, ctx->qry.path, ctx->qry.head);
 }
 
 static void commit_fn(struct cgit_context *ctx)
 {
 	cgit_print_commit(ctx->qry.sha1);
 }
 
 static void diff_fn(struct cgit_context *ctx)
 {
 	cgit_print_diff(ctx->qry.sha1, ctx->qry.sha2, ctx->qry.path);
 }
 
+static void info_fn(struct cgit_context *ctx)
+{
+	cgit_clone_info(ctx);
+}
+
 static void log_fn(struct cgit_context *ctx)
 {
 	cgit_print_log(ctx->qry.sha1, ctx->qry.ofs, ctx->cfg.max_commit_count,
 		       ctx->qry.grep, ctx->qry.search, ctx->qry.path, 1);
 }
 
 static void ls_cache_fn(struct cgit_context *ctx)
 {
 	ctx->page.mimetype = "text/plain";
 	ctx->page.filename = "ls-cache.txt";
 	cgit_print_http_headers(ctx);
 	cache_ls(ctx->cfg.cache_root);
 }
 
+static void objects_fn(struct cgit_context *ctx)
+{
+	cgit_clone_objects(ctx);
+}
+
 static void repolist_fn(struct cgit_context *ctx)
 {
 	cgit_print_repolist();
 }
 
 static void patch_fn(struct cgit_context *ctx)
 {
 	cgit_print_patch(ctx->qry.sha1);
 }
 
 static void refs_fn(struct cgit_context *ctx)
 {
 	cgit_print_refs();
 }
 
 static void snapshot_fn(struct cgit_context *ctx)
 {
 	cgit_print_snapshot(ctx->qry.head, ctx->qry.sha1,
 			    cgit_repobasename(ctx->repo->url), ctx->qry.path,
 			    ctx->repo->snapshots);
 }
 
 static void summary_fn(struct cgit_context *ctx)
 {
 	cgit_print_summary();
 }
 
 static void tag_fn(struct cgit_context *ctx)
 {
 	cgit_print_tag(ctx->qry.sha1);
 }
 
 static void tree_fn(struct cgit_context *ctx)
 {
 	cgit_print_tree(ctx->qry.sha1, ctx->qry.path);
 }
 
 #define def_cmd(name, want_repo, want_layout) \
 	{#name, name##_fn, want_repo, want_layout}
 
 struct cgit_cmd *cgit_get_cmd(struct cgit_context *ctx)
 {
 	static struct cgit_cmd cmds[] = {
+		def_cmd(HEAD, 1, 0),
 		def_cmd(about, 0, 1),
 		def_cmd(blob, 1, 0),
 		def_cmd(commit, 1, 1),
 		def_cmd(diff, 1, 1),
+		def_cmd(info, 1, 0),
 		def_cmd(log, 1, 1),
 		def_cmd(ls_cache, 0, 0),
+		def_cmd(objects, 1, 0),
 		def_cmd(patch, 1, 0),
 		def_cmd(refs, 1, 1),
 		def_cmd(repolist, 0, 0),
 		def_cmd(snapshot, 1, 0),
 		def_cmd(summary, 1, 1),
 		def_cmd(tag, 1, 1),
 		def_cmd(tree, 1, 1),
 	};
 	int i;
 
 	if (ctx->qry.page == NULL) {
 		if (ctx->repo)
 			ctx->qry.page = "summary";
 		else
 			ctx->qry.page = "repolist";
 	}
 
 	for(i = 0; i < sizeof(cmds)/sizeof(*cmds); i++)
 		if (!strcmp(ctx->qry.page, cmds[i].name))
 			return &cmds[i];
 	return NULL;
 }
diff --git a/html.c b/html.c
index bddb04d..1237076 100644
--- a/html.c
+++ b/html.c
@@ -6,96 +6,103 @@
  *   (see COPYING for full license text)
  */
 
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <string.h>
 #include <errno.h>
 
 int htmlfd = STDOUT_FILENO;
 
 char *fmt(const char *format, ...)
 {
 	static char buf[8][1024];
 	static int bufidx;
 	int len;
 	va_list args;
 
 	bufidx++;
 	bufidx &= 7;
 
 	va_start(args, format);
 	len = vsnprintf(buf[bufidx], sizeof(buf[bufidx]), format, args);
 	va_end(args);
 	if (len>sizeof(buf[bufidx])) {
 		fprintf(stderr, "[html.c] string truncated: %s\n", format);
 		exit(1);
 	}
 	return buf[bufidx];
 }
 
 void html(const char *txt)
 {
 	write(htmlfd, txt, strlen(txt));
 }
 
 void htmlf(const char *format, ...)
 {
 	static char buf[65536];
 	va_list args;
 
 	va_start(args, format);
 	vsnprintf(buf, sizeof(buf), format, args);
 	va_end(args);
 	html(buf);
 }
 
+void html_status(int code, int more_headers)
+{
+	htmlf("Status: %d\n", code);
+	if (!more_headers)
+		html("\n");
+}
+
 void html_txt(char *txt)
 {
 	char *t = txt;
 	while(t && *t){
 		int c = *t;
 		if (c=='<' || c=='>' || c=='&') {
 			write(htmlfd, txt, t - txt);
 			if (c=='>')
 				html("&gt;");
 			else if (c=='<')
 				html("&lt;");
 			else if (c=='&')
 				html("&amp;");
 			txt = t+1;
 		}
 		t++;
 	}
 	if (t!=txt)
 		html(txt);
 }
 
 void html_ntxt(int len, char *txt)
 {
 	char *t = txt;
 	while(t && *t && len--){
 		int c = *t;
 		if (c=='<' || c=='>' || c=='&') {
 			write(htmlfd, txt, t - txt);
 			if (c=='>')
 				html("&gt;");
 			else if (c=='<')
 				html("&lt;");
 			else if (c=='&')
 				html("&amp;");
 			txt = t+1;
 		}
 		t++;
 	}
 	if (t!=txt)
 		write(htmlfd, txt, t - txt);
 	if (len<0)
 		html("...");
 }
 
 void html_attr(char *txt)
 {
 	char *t = txt;
 	while(t && *t){
diff --git a/html.h b/html.h
index e6fdc54..2bde28d 100644
--- a/html.h
+++ b/html.h
@@ -1,20 +1,21 @@
 #ifndef HTML_H
 #define HTML_H
 
 extern int htmlfd;
 
 extern void html(const char *txt);
 extern void htmlf(const char *format,...);
+extern void html_status(int code, int more_headers);
 extern void html_txt(char *txt);
 extern void html_ntxt(int len, char *txt);
 extern void html_attr(char *txt);
 extern void html_hidden(char *name, char *value);
 extern void html_option(char *value, char *text, char *selected_value);
 extern void html_link_open(char *url, char *title, char *class);
 extern void html_link_close(void);
 extern void html_fileperm(unsigned short mode);
 extern int html_include(const char *filename);
 
 extern int http_parse_querystring(char *txt, void (*fn)(const char *name, const char *value));
 
 #endif /* HTML_H */
diff --git a/ui-clone.c b/ui-clone.c
new file mode 100644
index 0000000..3a037ad
--- a/dev/null
+++ b/ui-clone.c
@@ -0,0 +1,104 @@
+/* ui-clone.c: functions for http cloning, based on
+ * git's http-backend.c by Shawn O. Pearce
+ *
+ * Copyright (C) 2008 Lars Hjemli
+ *
+ * Licensed under GNU General Public License v2
+ *   (see COPYING for full license text)
+ */
+
+#include "cgit.h"
+#include "html.h"
+#include "ui-shared.h"
+
+static int print_ref_info(const char *refname, const unsigned char *sha1,
+                          int flags, void *cb_data)
+{
+	struct object *obj;
+
+	if (!(obj = parse_object(sha1)))
+		return 0;
+
+	if (!strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/"))
+		htmlf("%s\t%s\n", sha1_to_hex(sha1), refname);
+	else if (!prefixcmp(refname, "refs/tags") && obj->type == OBJ_TAG) {
+		if (!(obj = deref_tag(obj, refname, 0)))
+			return 0;
+		htmlf("%s\t%s\n", sha1_to_hex(sha1), refname);
+		htmlf("%s\t%s^{}\n", sha1_to_hex(obj->sha1), refname);
+	}
+	return 0;
+}
+
+static void print_pack_info(struct cgit_context *ctx)
+{
+	struct packed_git *pack;
+	int ofs;
+
+	ctx->page.mimetype = "text/plain";
+	ctx->page.filename = "objects/info/packs";
+	cgit_print_http_headers(ctx);
+	ofs = strlen(ctx->repo->path) + strlen("/objects/pack/");
+	prepare_packed_git();
+	for (pack = packed_git; pack; pack = pack->next)
+		if (pack->pack_local)
+			htmlf("P %s\n", pack->pack_name + ofs);
+}
+
+static void send_file(struct cgit_context *ctx, char *path)
+{
+	struct stat st;
+	int err;
+
+	if (stat(path, &st)) {
+		switch (errno) {
+		case ENOENT:
+			err = 404;
+			break;
+		case EACCES:
+			err = 403;
+			break;
+		default:
+			err = 400;
+		}
+		html_status(err, 0);
+		return;
+	}
+	ctx->page.mimetype = "application/octet-stream";
+	ctx->page.filename = path;
+	if (prefixcmp(ctx->repo->path, path))
+		ctx->page.filename += strlen(ctx->repo->path) + 1;
+	cgit_print_http_headers(ctx);
+	html_include(path);
+}
+
+void cgit_clone_info(struct cgit_context *ctx)
+{
+	if (!ctx->qry.path || strcmp(ctx->qry.path, "refs"))
+		return;
+
+	ctx->page.mimetype = "text/plain";
+	ctx->page.filename = "info/refs";
+	cgit_print_http_headers(ctx);
+	for_each_ref(print_ref_info, ctx);
+}
+
+void cgit_clone_objects(struct cgit_context *ctx)
+{
+	if (!ctx->qry.path) {
+		html_status(400, 0);
+		return;
+	}
+
+	if (!strcmp(ctx->qry.path, "info/packs")) {
+		print_pack_info(ctx);
+		return;
+	}
+
+	send_file(ctx, git_path("objects/%s", ctx->qry.path));
+}
+
+void cgit_clone_head(struct cgit_context *ctx)
+{
+	send_file(ctx, git_path("%s", "HEAD"));
+}
diff --git a/ui-clone.h b/ui-clone.h
new file mode 100644
index 0000000..89cd4f1
--- a/dev/null
+++ b/ui-clone.h
@@ -0,0 +1,8 @@
+#ifndef UI_CLONE_H
+#define UI_CLONE_H
+
+void cgit_clone_info(struct cgit_context *ctx);
+void cgit_clone_objects(struct cgit_context *ctx);
+void cgit_clone_head(struct cgit_context *ctx);
+
+#endif /* UI_CLONE_H */