1 files changed, 246 insertions, 0 deletions
diff --git a/src/lib-mail/message-search.c b/src/lib-mail/message-search.c
new file mode 100644
index 0000000..5f54485
--- /dev/null
+++ b/src/lib-mail/message-search.c
@@ -0,0 +1,246 @@
+/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "buffer.h"
+#include "istream.h"
+#include "str.h"
+#include "str-find.h"
+#include "rfc822-parser.h"
+#include "message-decoder.h"
+#include "message-parser.h"
+#include "message-search.h"
+
+struct message_search_context {
+	enum message_search_flags flags;
+	normalizer_func_t *normalizer;
+
+	struct str_find_context *str_find_ctx;
+	struct message_part *prev_part;
+
+	struct message_decoder_context *decoder;
+	bool content_type_text:1; /* text/any or message/any */
+};
+
+struct message_search_context *
+message_search_init(const char *normalized_key_utf8,
+		    normalizer_func_t *normalizer,
+		    enum message_search_flags flags)
+{
+	struct message_search_context *ctx;
+
+	i_assert(*normalized_key_utf8 != '\0');
+
+	ctx = i_new(struct message_search_context, 1);
+	ctx->flags = flags;
+	ctx->decoder = message_decoder_init(normalizer, 0);
+	ctx->str_find_ctx = str_find_init(default_pool, normalized_key_utf8);
+	return ctx;
+}
+
+void message_search_deinit(struct message_search_context **_ctx)
+{
+	struct message_search_context *ctx = *_ctx;
+
+	*_ctx = NULL;
+	str_find_deinit(&ctx->str_find_ctx);
+	message_decoder_deinit(&ctx->decoder);
+	i_free(ctx);
+}
+
+static void parse_content_type(struct message_search_context *ctx,
+			       struct message_header_line *hdr)
+{
+	struct rfc822_parser_context parser;
+	string_t *content_type;
+
+	rfc822_parser_init(&parser, hdr->full_value, hdr->full_value_len, NULL);
+	rfc822_skip_lwsp(&parser);
+
+	content_type = t_str_new(64);
+	(void)rfc822_parse_content_type(&parser, content_type);
+	ctx->content_type_text =
+		strncasecmp(str_c(content_type), "text/", 5) == 0 ||
+		strncasecmp(str_c(content_type), "message/", 8) == 0;
+	rfc822_parser_deinit(&parser);
+}
+
+static void handle_header(struct message_search_context *ctx,
+			  struct message_header_line *hdr)
+{
+	if (hdr->name_len == 12 &&
+	    strcasecmp(hdr->name, "Content-Type") == 0) {
+		if (hdr->continues) {
+			hdr->use_full_value = TRUE;
+			return;
+		}
+		T_BEGIN {
+			parse_content_type(ctx, hdr);
+		} T_END;
+	}
+}
+
+static bool search_header(struct message_search_context *ctx,
+			  const struct message_header_line *hdr)
+{
+	static const unsigned char crlf[2] = { '\r', '\n' };
+
+	return str_find_more(ctx->str_find_ctx,
+			     (const unsigned char *)hdr->name, hdr->name_len) ||
+		str_find_more(ctx->str_find_ctx,
+			      hdr->middle, hdr->middle_len) ||
+		str_find_more(ctx->str_find_ctx, hdr->full_value,
+			      hdr->full_value_len) ||
+		(!hdr->no_newline &&
+		 str_find_more(ctx->str_find_ctx, crlf, 2));
+}
+
+static bool message_search_more_decoded2(struct message_search_context *ctx,
+					 struct message_block *block)
+{
+	if (block->hdr != NULL) {
+		if (search_header(ctx, block->hdr))
+			return TRUE;
+	} else {
+		if (str_find_more(ctx->str_find_ctx, block->data, block->size))
+			return TRUE;
+	}
+	return FALSE;
+}
+
+bool message_search_more(struct message_search_context *ctx,
+			 struct message_block *raw_block)
+{
+	struct message_block decoded_block;
+
+	return message_search_more_get_decoded(ctx, raw_block, &decoded_block);
+}
+
+bool message_search_more_get_decoded(struct message_search_context *ctx,
+				     struct message_block *raw_block,
+				     struct message_block *decoded_block_r)
+{
+	struct message_header_line *hdr = raw_block->hdr;
+	struct message_block decoded_block;
+
+	i_zero(decoded_block_r);
+	decoded_block_r->part = raw_block->part;
+
+	if (raw_block->part != ctx->prev_part) {
+		/* part changes. we must change this before looking at
+		   content type */
+		message_search_reset(ctx);
+		ctx->prev_part = raw_block->part;
+
+		if (hdr == NULL) {
+			/* we're returning to a multipart message. */
+			ctx->content_type_text = FALSE;
+		}
+	}
+
+	if (hdr != NULL) {
+		handle_header(ctx, hdr);
+		if ((ctx->flags & MESSAGE_SEARCH_FLAG_SKIP_HEADERS) != 0) {
+			/* we want to search only message bodies, but
+			   but decoder needs some headers so that it can
+			   decode the body properly. */
+			if (hdr->name_len != 12 && hdr->name_len != 25)
+				return FALSE;
+			if (strcasecmp(hdr->name, "Content-Type") != 0 &&
+			    strcasecmp(hdr->name,
+				       "Content-Transfer-Encoding") != 0)
+				return FALSE;
+		}
+	} else {
+		/* body */
+		if (!ctx->content_type_text)
+			return FALSE;
+	}
+	if (!message_decoder_decode_next_block(ctx->decoder, raw_block,
+					       &decoded_block))
+		return FALSE;
+
+	if (decoded_block.hdr != NULL &&
+	    (ctx->flags & MESSAGE_SEARCH_FLAG_SKIP_HEADERS) != 0) {
+		/* Content-* header */
+		return FALSE;
+	}
+
+	*decoded_block_r = decoded_block;
+	return message_search_more_decoded2(ctx, &decoded_block);
+}
+
+bool message_search_more_decoded(struct message_search_context *ctx,
+				 struct message_block *block)
+{
+	if (block->part != ctx->prev_part) {
+		/* part changes */
+		message_search_reset(ctx);
+		ctx->prev_part = block->part;
+	}
+
+	return message_search_more_decoded2(ctx, block);
+}
+
+void message_search_reset(struct message_search_context *ctx)
+{
+	/* Content-Type defaults to text/plain */
+	ctx->content_type_text = TRUE;
+
+	ctx->prev_part = NULL;
+	str_find_reset(ctx->str_find_ctx);
+	message_decoder_decode_reset(ctx->decoder);
+}
+
+static int
+message_search_msg_real(struct message_search_context *ctx,
+			struct istream *input, struct message_part *parts,
+			const char **error_r)
+{
+	const struct message_parser_settings parser_set = {
+		.hdr_flags = MESSAGE_HEADER_PARSER_FLAG_CLEAN_ONELINE,
+	};
+	struct message_parser_ctx *parser_ctx;
+	struct message_block raw_block;
+	struct message_part *new_parts;
+	int ret;
+
+	message_search_reset(ctx);
+
+	if (parts != NULL) {
+		parser_ctx = message_parser_init_from_parts(parts,
+						input, &parser_set);
+	} else {
+		parser_ctx = message_parser_init(pool_datastack_create(),
+						 input, &parser_set);
+	}
+
+	while ((ret = message_parser_parse_next_block(parser_ctx,
+						      &raw_block)) > 0) {
+		if (message_search_more(ctx, &raw_block)) {
+			ret = 1;
+			break;
+		}
+	}
+	i_assert(ret != 0);
+	if (ret < 0 && input->stream_errno == 0) {
+		/* normal exit */
+		ret = 0;
+	}
+	if (message_parser_deinit_from_parts(&parser_ctx, &new_parts, error_r) < 0) {
+		/* broken parts */
+		ret = -1;
+	}
+	return ret;
+}
+
+int message_search_msg(struct message_search_context *ctx,
+		       struct istream *input, struct message_part *parts,
+		       const char **error_r)
+{
+	int ret;
+
+	T_BEGIN {
+		ret = message_search_msg_real(ctx, input, parts, error_r);
+	} T_END_PASS_STR_IF(ret < 0, error_r);
+	return ret;
+}