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-rw-r--r--filter.c457
1 files changed, 457 insertions, 0 deletions
diff --git a/filter.c b/filter.c
new file mode 100644
index 000000000000..70f5b749989c
--- /dev/null
+++ b/filter.c
@@ -0,0 +1,457 @@
+/* filter.c: filter framework functions
+ *
+ * Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
+ *
+ * Licensed under GNU General Public License v2
+ *   (see COPYING for full license text)
+ */
+
+#include "cgit.h"
+#include "html.h"
+#ifndef NO_LUA
+#include <dlfcn.h>
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+#endif
+
+static inline void reap_filter(struct cgit_filter *filter)
+{
+	if (filter && filter->cleanup)
+		filter->cleanup(filter);
+}
+
+void cgit_cleanup_filters(void)
+{
+	int i;
+	reap_filter(ctx.cfg.about_filter);
+	reap_filter(ctx.cfg.commit_filter);
+	reap_filter(ctx.cfg.source_filter);
+	reap_filter(ctx.cfg.email_filter);
+	reap_filter(ctx.cfg.owner_filter);
+	reap_filter(ctx.cfg.auth_filter);
+	for (i = 0; i < cgit_repolist.count; ++i) {
+		reap_filter(cgit_repolist.repos[i].about_filter);
+		reap_filter(cgit_repolist.repos[i].commit_filter);
+		reap_filter(cgit_repolist.repos[i].source_filter);
+		reap_filter(cgit_repolist.repos[i].email_filter);
+		reap_filter(cgit_repolist.repos[i].owner_filter);
+	}
+}
+
+static int open_exec_filter(struct cgit_filter *base, va_list ap)
+{
+	struct cgit_exec_filter *filter = (struct cgit_exec_filter *)base;
+	int pipe_fh[2];
+	int i;
+
+	for (i = 0; i < filter->base.argument_count; i++)
+		filter->argv[i + 1] = va_arg(ap, char *);
+
+	filter->old_stdout = chk_positive(dup(STDOUT_FILENO),
+		"Unable to duplicate STDOUT");
+	chk_zero(pipe(pipe_fh), "Unable to create pipe to subprocess");
+	filter->pid = chk_non_negative(fork(), "Unable to create subprocess");
+	if (filter->pid == 0) {
+		close(pipe_fh[1]);
+		chk_non_negative(dup2(pipe_fh[0], STDIN_FILENO),
+			"Unable to use pipe as STDIN");
+		execvp(filter->cmd, filter->argv);
+		die_errno("Unable to exec subprocess %s", filter->cmd);
+	}
+	close(pipe_fh[0]);
+	chk_non_negative(dup2(pipe_fh[1], STDOUT_FILENO),
+		"Unable to use pipe as STDOUT");
+	close(pipe_fh[1]);
+	return 0;
+}
+
+static int close_exec_filter(struct cgit_filter *base)
+{
+	struct cgit_exec_filter *filter = (struct cgit_exec_filter *)base;
+	int i, exit_status = 0;
+
+	chk_non_negative(dup2(filter->old_stdout, STDOUT_FILENO),
+		"Unable to restore STDOUT");
+	close(filter->old_stdout);
+	if (filter->pid < 0)
+		goto done;
+	waitpid(filter->pid, &exit_status, 0);
+	if (WIFEXITED(exit_status))
+		goto done;
+	die("Subprocess %s exited abnormally", filter->cmd);
+
+done:
+	for (i = 0; i < filter->base.argument_count; i++)
+		filter->argv[i + 1] = NULL;
+	return WEXITSTATUS(exit_status);
+
+}
+
+static void fprintf_exec_filter(struct cgit_filter *base, FILE *f, const char *prefix)
+{
+	struct cgit_exec_filter *filter = (struct cgit_exec_filter *)base;
+	fprintf(f, "%sexec:%s\n", prefix, filter->cmd);
+}
+
+static void cleanup_exec_filter(struct cgit_filter *base)
+{
+	struct cgit_exec_filter *filter = (struct cgit_exec_filter *)base;
+	if (filter->argv) {
+		free(filter->argv);
+		filter->argv = NULL;
+	}
+	if (filter->cmd) {
+		free(filter->cmd);
+		filter->cmd = NULL;
+	}
+}
+
+static struct cgit_filter *new_exec_filter(const char *cmd, int argument_count)
+{
+	struct cgit_exec_filter *f;
+	int args_size = 0;
+
+	f = xmalloc(sizeof(*f));
+	/* We leave argv for now and assign it below. */
+	cgit_exec_filter_init(f, xstrdup(cmd), NULL);
+	f->base.argument_count = argument_count;
+	args_size = (2 + argument_count) * sizeof(char *);
+	f->argv = xmalloc(args_size);
+	memset(f->argv, 0, args_size);
+	f->argv[0] = f->cmd;
+	return &f->base;
+}
+
+void cgit_exec_filter_init(struct cgit_exec_filter *filter, char *cmd, char **argv)
+{
+	memset(filter, 0, sizeof(*filter));
+	filter->base.open = open_exec_filter;
+	filter->base.close = close_exec_filter;
+	filter->base.fprintf = fprintf_exec_filter;
+	filter->base.cleanup = cleanup_exec_filter;
+	filter->cmd = cmd;
+	filter->argv = argv;
+	/* The argument count for open_filter is zero by default, unless called from new_filter, above. */
+	filter->base.argument_count = 0;
+}
+
+#ifdef NO_LUA
+void cgit_init_filters(void)
+{
+}
+#endif
+
+#ifndef NO_LUA
+static ssize_t (*libc_write)(int fd, const void *buf, size_t count);
+static ssize_t (*filter_write)(struct cgit_filter *base, const void *buf, size_t count) = NULL;
+static struct cgit_filter *current_write_filter = NULL;
+
+void cgit_init_filters(void)
+{
+	libc_write = dlsym(RTLD_NEXT, "write");
+	if (!libc_write)
+		die("Could not locate libc's write function");
+}
+
+ssize_t write(int fd, const void *buf, size_t count)
+{
+	if (fd != STDOUT_FILENO || !filter_write)
+		return libc_write(fd, buf, count);
+	return filter_write(current_write_filter, buf, count);
+}
+
+static inline void hook_write(struct cgit_filter *filter, ssize_t (*new_write)(struct cgit_filter *base, const void *buf, size_t count))
+{
+	/* We want to avoid buggy nested patterns. */
+	assert(filter_write == NULL);
+	assert(current_write_filter == NULL);
+	current_write_filter = filter;
+	filter_write = new_write;
+}
+
+static inline void unhook_write(void)
+{
+	assert(filter_write != NULL);
+	assert(current_write_filter != NULL);
+	filter_write = NULL;
+	current_write_filter = NULL;
+}
+
+struct lua_filter {
+	struct cgit_filter base;
+	char *script_file;
+	lua_State *lua_state;
+};
+
+static void error_lua_filter(struct lua_filter *filter)
+{
+	die("Lua error in %s: %s", filter->script_file, lua_tostring(filter->lua_state, -1));
+	lua_pop(filter->lua_state, 1);
+}
+
+static ssize_t write_lua_filter(struct cgit_filter *base, const void *buf, size_t count)
+{
+	struct lua_filter *filter = (struct lua_filter *)base;
+
+	lua_getglobal(filter->lua_state, "filter_write");
+	lua_pushlstring(filter->lua_state, buf, count);
+	if (lua_pcall(filter->lua_state, 1, 0, 0)) {
+		error_lua_filter(filter);
+		errno = EIO;
+		return -1;
+	}
+	return count;
+}
+
+static inline int hook_lua_filter(lua_State *lua_state, void (*fn)(const char *txt))
+{
+	const char *str;
+	ssize_t (*save_filter_write)(struct cgit_filter *base, const void *buf, size_t count);
+	struct cgit_filter *save_filter;
+
+	str = lua_tostring(lua_state, 1);
+	if (!str)
+		return 0;
+
+	save_filter_write = filter_write;
+	save_filter = current_write_filter;
+	unhook_write();
+	fn(str);
+	hook_write(save_filter, save_filter_write);
+
+	return 0;
+}
+
+static int html_lua_filter(lua_State *lua_state)
+{
+	return hook_lua_filter(lua_state, html);
+}
+
+static int html_txt_lua_filter(lua_State *lua_state)
+{
+	return hook_lua_filter(lua_state, html_txt);
+}
+
+static int html_attr_lua_filter(lua_State *lua_state)
+{
+	return hook_lua_filter(lua_state, html_attr);
+}
+
+static int html_url_path_lua_filter(lua_State *lua_state)
+{
+	return hook_lua_filter(lua_state, html_url_path);
+}
+
+static int html_url_arg_lua_filter(lua_State *lua_state)
+{
+	return hook_lua_filter(lua_state, html_url_arg);
+}
+
+static int html_include_lua_filter(lua_State *lua_state)
+{
+	return hook_lua_filter(lua_state, (void (*)(const char *))html_include);
+}
+
+static void cleanup_lua_filter(struct cgit_filter *base)
+{
+	struct lua_filter *filter = (struct lua_filter *)base;
+
+	if (!filter->lua_state)
+		return;
+
+	lua_close(filter->lua_state);
+	filter->lua_state = NULL;
+	if (filter->script_file) {
+		free(filter->script_file);
+		filter->script_file = NULL;
+	}
+}
+
+static int init_lua_filter(struct lua_filter *filter)
+{
+	if (filter->lua_state)
+		return 0;
+
+	if (!(filter->lua_state = luaL_newstate()))
+		return 1;
+
+	luaL_openlibs(filter->lua_state);
+
+	lua_pushcfunction(filter->lua_state, html_lua_filter);
+	lua_setglobal(filter->lua_state, "html");
+	lua_pushcfunction(filter->lua_state, html_txt_lua_filter);
+	lua_setglobal(filter->lua_state, "html_txt");
+	lua_pushcfunction(filter->lua_state, html_attr_lua_filter);
+	lua_setglobal(filter->lua_state, "html_attr");
+	lua_pushcfunction(filter->lua_state, html_url_path_lua_filter);
+	lua_setglobal(filter->lua_state, "html_url_path");
+	lua_pushcfunction(filter->lua_state, html_url_arg_lua_filter);
+	lua_setglobal(filter->lua_state, "html_url_arg");
+	lua_pushcfunction(filter->lua_state, html_include_lua_filter);
+	lua_setglobal(filter->lua_state, "html_include");
+
+	if (luaL_dofile(filter->lua_state, filter->script_file)) {
+		error_lua_filter(filter);
+		lua_close(filter->lua_state);
+		filter->lua_state = NULL;
+		return 1;
+	}
+	return 0;
+}
+
+static int open_lua_filter(struct cgit_filter *base, va_list ap)
+{
+	struct lua_filter *filter = (struct lua_filter *)base;
+	int i;
+
+	if (init_lua_filter(filter))
+		return 1;
+
+	hook_write(base, write_lua_filter);
+
+	lua_getglobal(filter->lua_state, "filter_open");
+	for (i = 0; i < filter->base.argument_count; ++i)
+		lua_pushstring(filter->lua_state, va_arg(ap, char *));
+	if (lua_pcall(filter->lua_state, filter->base.argument_count, 0, 0)) {
+		error_lua_filter(filter);
+		return 1;
+	}
+	return 0;
+}
+
+static int close_lua_filter(struct cgit_filter *base)
+{
+	struct lua_filter *filter = (struct lua_filter *)base;
+	int ret = 0;
+
+	lua_getglobal(filter->lua_state, "filter_close");
+	if (lua_pcall(filter->lua_state, 0, 1, 0)) {
+		error_lua_filter(filter);
+		ret = -1;
+	} else {
+		ret = lua_tonumber(filter->lua_state, -1);
+		lua_pop(filter->lua_state, 1);
+	}
+
+	unhook_write();
+	return ret;
+}
+
+static void fprintf_lua_filter(struct cgit_filter *base, FILE *f, const char *prefix)
+{
+	struct lua_filter *filter = (struct lua_filter *)base;
+	fprintf(f, "%slua:%s\n", prefix, filter->script_file);
+}
+
+
+static struct cgit_filter *new_lua_filter(const char *cmd, int argument_count)
+{
+	struct lua_filter *filter;
+
+	filter = xmalloc(sizeof(*filter));
+	memset(filter, 0, sizeof(*filter));
+	filter->base.open = open_lua_filter;
+	filter->base.close = close_lua_filter;
+	filter->base.fprintf = fprintf_lua_filter;
+	filter->base.cleanup = cleanup_lua_filter;
+	filter->base.argument_count = argument_count;
+	filter->script_file = xstrdup(cmd);
+
+	return &filter->base;
+}
+
+#endif
+
+
+int cgit_open_filter(struct cgit_filter *filter, ...)
+{
+	int result;
+	va_list ap;
+	if (!filter)
+		return 0;
+	va_start(ap, filter);
+	result = filter->open(filter, ap);
+	va_end(ap);
+	return result;
+}
+
+int cgit_close_filter(struct cgit_filter *filter)
+{
+	if (!filter)
+		return 0;
+	return filter->close(filter);
+}
+
+void cgit_fprintf_filter(struct cgit_filter *filter, FILE *f, const char *prefix)
+{
+	filter->fprintf(filter, f, prefix);
+}
+
+
+
+static const struct {
+	const char *prefix;
+	struct cgit_filter *(*ctor)(const char *cmd, int argument_count);
+} filter_specs[] = {
+	{ "exec", new_exec_filter },
+#ifndef NO_LUA
+	{ "lua", new_lua_filter },
+#endif
+};
+
+struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype)
+{
+	char *colon;
+	int i;
+	size_t len;
+	int argument_count;
+
+	if (!cmd || !cmd[0])
+		return NULL;
+
+	colon = strchr(cmd, ':');
+	len = colon - cmd;
+	/*
+	 * In case we're running on Windows, don't allow a single letter before
+	 * the colon.
+	 */
+	if (len == 1)
+		colon = NULL;
+
+	switch (filtertype) {
+		case AUTH:
+			argument_count = 12;
+			break;
+
+		case EMAIL:
+			argument_count = 2;
+			break;
+
+		case OWNER:
+			argument_count = 0;
+			break;
+
+		case SOURCE:
+		case ABOUT:
+			argument_count = 1;
+			break;
+
+		case COMMIT:
+		default:
+			argument_count = 0;
+			break;
+	}
+
+	/* If no prefix is given, exec filter is the default. */
+	if (!colon)
+		return new_exec_filter(cmd, argument_count);
+
+	for (i = 0; i < ARRAY_SIZE(filter_specs); i++) {
+		if (len == strlen(filter_specs[i].prefix) &&
+		    !strncmp(filter_specs[i].prefix, cmd, len))
+			return filter_specs[i].ctor(colon + 1, argument_count);
+	}
+
+	die("Invalid filter type: %.*s", (int) len, cmd);
+}