1 files changed, 277 insertions, 0 deletions
diff --git a/src/plugins/fts/fts-parser-script.c b/src/plugins/fts/fts-parser-script.c
new file mode 100644
index 0000000..eefbe07
--- /dev/null
+++ b/src/plugins/fts/fts-parser-script.c
@@ -0,0 +1,277 @@
+/* Copyright (c) 2011-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "str.h"
+#include "net.h"
+#include "istream.h"
+#include "write-full.h"
+#include "module-context.h"
+#include "rfc822-parser.h"
+#include "rfc2231-parser.h"
+#include "message-parser.h"
+#include "mail-user.h"
+#include "fts-parser.h"
+
+#define SCRIPT_USER_CONTEXT(obj) \
+	MODULE_CONTEXT(obj, fts_parser_script_user_module)
+
+#define SCRIPT_HANDSHAKE "VERSION\tscript\t4\t0\nalarm=10\nnoreply\n"
+
+struct content {
+	const char *content_type;
+	const char *const *extensions;
+};
+
+struct fts_parser_script_user {
+	union mail_user_module_context module_ctx;
+
+	ARRAY(struct content) content;
+};
+
+struct script_fts_parser {
+	struct fts_parser parser;
+
+	int fd;
+	char *path;
+
+	unsigned char outbuf[IO_BLOCK_SIZE];
+	bool failed;
+	bool shutdown;
+};
+
+static MODULE_CONTEXT_DEFINE_INIT(fts_parser_script_user_module,
+				  &mail_user_module_register);
+
+static int script_connect(struct mail_user *user, const char **path_r)
+{
+	const char *path;
+	int fd;
+
+	path = mail_user_plugin_getenv(user, "fts_decoder");
+	if (path == NULL)
+		return -1;
+
+	if (*path != '/')
+		path = t_strconcat(user->set->base_dir, "/", path, NULL);
+	fd = net_connect_unix_with_retries(path, 1000);
+	if (fd == -1)
+		i_error("net_connect_unix(%s) failed: %m", path);
+	else
+		net_set_nonblock(fd, FALSE);
+	*path_r = path;
+	return fd;
+}
+
+static int script_contents_read(struct mail_user *user)
+{
+	struct fts_parser_script_user *suser = SCRIPT_USER_CONTEXT(user);
+	const char *path, *cmd, *line;
+	char **args;
+	struct istream *input;
+	struct content *content;
+	bool eof_seen = FALSE;
+	int fd, ret = 0;
+	i_assert(suser != NULL);
+
+	fd = script_connect(user, &path);
+	if (fd == -1)
+		return -1;
+
+	cmd = t_strdup_printf(SCRIPT_HANDSHAKE"\n");
+	if (write_full(fd, cmd, strlen(cmd)) < 0) {
+		i_error("write(%s) failed: %m", path);
+		i_close_fd(&fd);
+		return -1;
+	}
+	input = i_stream_create_fd_autoclose(&fd, 1024);
+	while ((line = i_stream_read_next_line(input)) != NULL) {
+		/* <content-type> <extension> [<extension> ...] */
+		args = p_strsplit_spaces(user->pool, line, " ");
+		if (args[0] == NULL) {
+			eof_seen = TRUE;
+			break;
+		}
+		if (args[0][0] == '\0' || args[1] == NULL) {
+			i_error("parser script sent invalid input: %s", line);
+			continue;
+		}
+
+		content = array_append_space(&suser->content);
+		content->content_type = str_lcase(args[0]);
+		content->extensions = (const void *)(args+1);
+	}
+	if (input->stream_errno != 0) {
+		i_error("parser script read(%s) failed: %s", path,
+			i_stream_get_error(input));
+		ret = -1;
+	} else if (!eof_seen) {
+		if (input->v_offset == 0)
+			i_error("parser script didn't send any data");
+		else
+			i_error("parser script didn't send empty EOF line");
+	}
+	i_stream_destroy(&input);
+	return ret;
+}
+
+static bool script_support_content(struct mail_user *user,
+				   const char **content_type,
+				   const char *filename)
+{
+	struct fts_parser_script_user *suser = SCRIPT_USER_CONTEXT(user);
+	const struct content *content;
+	const char *extension;
+
+	if (suser == NULL) {
+		suser = p_new(user->pool, struct fts_parser_script_user, 1);
+		p_array_init(&suser->content, user->pool, 32);
+		MODULE_CONTEXT_SET(user, fts_parser_script_user_module, suser);
+	}
+	if (array_count(&suser->content) == 0) {
+		if (script_contents_read(user) < 0)
+			return FALSE;
+	}
+
+	if (strcmp(*content_type, "application/octet-stream") == 0) {
+		if (filename == NULL)
+			return FALSE;
+		extension = strrchr(filename, '.');
+		if (extension == NULL)
+			return FALSE;
+		extension = extension + 1;
+
+		array_foreach(&suser->content, content) {
+			if (content->extensions != NULL &&
+			    str_array_icase_find(content->extensions, extension)) {
+				*content_type = content->content_type;
+				return TRUE;
+			}
+		}
+	} else {
+		array_foreach(&suser->content, content) {
+			if (strcmp(content->content_type, *content_type) == 0)
+				return TRUE;
+		}
+	}
+	return FALSE;
+}
+
+static void parse_content_disposition(const char *content_disposition,
+				      const char **filename_r)
+{
+	struct rfc822_parser_context parser;
+	const char *const *results, *filename2;
+	string_t *str;
+
+	*filename_r = NULL;
+
+	if (content_disposition == NULL)
+		return;
+
+	rfc822_parser_init(&parser, (const unsigned char *)content_disposition,
+			   strlen(content_disposition), NULL);
+	rfc822_skip_lwsp(&parser);
+
+	/* type; param; param; .. */
+	str = t_str_new(32);
+	if (rfc822_parse_mime_token(&parser, str) < 0) {
+		rfc822_parser_deinit(&parser);
+		return;
+	}
+
+	rfc2231_parse(&parser, &results);
+	filename2 = NULL;
+	for (; *results != NULL; results += 2) {
+		if (strcasecmp(results[0], "filename") == 0) {
+			*filename_r = results[1];
+			break;
+		}
+		if (strcasecmp(results[0], "filename*") == 0)
+			filename2 = results[1];
+	}
+	if (*filename_r == NULL) {
+		/* RFC 2231 style non-ascii filename. we don't really care
+		   much about the filename actually, just about its extension */
+		*filename_r = filename2;
+	}
+	rfc822_parser_deinit(&parser);
+}
+
+static struct fts_parser *
+fts_parser_script_try_init(struct fts_parser_context *parser_context)
+{
+	struct script_fts_parser *parser;
+	const char *filename, *path, *cmd;
+	int fd;
+
+	parse_content_disposition(parser_context->content_disposition, &filename);
+	if (!script_support_content(parser_context->user, &parser_context->content_type, filename))
+		return NULL;
+
+	fd = script_connect(parser_context->user, &path);
+	if (fd == -1)
+		return NULL;
+	cmd = t_strdup_printf(SCRIPT_HANDSHAKE"%s\n\n", parser_context->content_type);
+	if (write_full(fd, cmd, strlen(cmd)) < 0) {
+		i_error("write(%s) failed: %m", path);
+		i_close_fd(&fd);
+		return NULL;
+	}
+
+	parser = i_new(struct script_fts_parser, 1);
+	parser->parser.v = fts_parser_script;
+	parser->path = i_strdup(path);
+	parser->fd = fd;
+	return &parser->parser;
+}
+
+static void fts_parser_script_more(struct fts_parser *_parser,
+				   struct message_block *block)
+{
+	struct script_fts_parser *parser = (struct script_fts_parser *)_parser;
+	ssize_t ret;
+
+	if (block->size > 0) {
+		/* first we'll send everything to the script */
+		if (!parser->failed &&
+		    write_full(parser->fd, block->data, block->size) < 0) {
+			i_error("write(%s) failed: %m", parser->path);
+			parser->failed = TRUE;
+		}
+		block->size = 0;
+	} else {
+		if (!parser->shutdown) {
+			if (shutdown(parser->fd, SHUT_WR) < 0)
+				i_error("shutdown(%s) failed: %m", parser->path);
+			parser->shutdown = TRUE;
+		}
+		/* read the result from the script */
+		ret = read(parser->fd, parser->outbuf, sizeof(parser->outbuf));
+		if (ret < 0)
+			i_error("read(%s) failed: %m", parser->path);
+		else {
+			block->data = parser->outbuf;
+			block->size = ret;
+		}
+	}
+}
+
+static int fts_parser_script_deinit(struct fts_parser *_parser,
+				    const char **retriable_err_msg_r ATTR_UNUSED)
+{
+	struct script_fts_parser *parser = (struct script_fts_parser *)_parser;
+	int ret = parser->failed ? -1 : 1;
+
+	if (close(parser->fd) < 0)
+		i_error("close(%s) failed: %m", parser->path);
+	i_free(parser->path);
+	i_free(parser);
+	return ret;
+}
+
+struct fts_parser_vfuncs fts_parser_script = {
+	fts_parser_script_try_init,
+	fts_parser_script_more,
+	fts_parser_script_deinit,
+	NULL
+};