Mercurial > dovecot > core-2.2
view src/lib-http/http-message-parser.c @ 21557:219ec946f7c3
lib-http: message parser: Don't create the connection_options array, unless it is actually used.
author | Stephan Bosch <stephan.bosch@dovecot.fi> |
---|---|
date | Sat, 04 Feb 2017 14:03:25 +0100 |
parents | 2e2563132d5f |
children | 390c3ef87cc8 |
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/* Copyright (c) 2013-2017 Dovecot authors, see the included COPYING file */ #include "lib.h" #include "array.h" #include "istream.h" #include "iostream.h" #include "istream-sized.h" #include "http-parser.h" #include "http-header.h" #include "http-header-parser.h" #include "http-date.h" #include "http-transfer.h" #include "http-message-parser.h" #include <ctype.h> void http_message_parser_init(struct http_message_parser *parser, struct istream *input, const struct http_header_limits *hdr_limits, uoff_t max_payload_size, bool lenient) { i_zero(parser); parser->input = input; i_stream_ref(parser->input); if (hdr_limits != NULL) parser->header_limits = *hdr_limits; parser->max_payload_size = max_payload_size; parser->lenient = lenient; } void http_message_parser_deinit(struct http_message_parser *parser) { if (parser->header_parser != NULL) http_header_parser_deinit(&parser->header_parser); if (parser->msg.pool != NULL) pool_unref(&parser->msg.pool); if (parser->payload != NULL) i_stream_unref(&parser->payload); if (parser->input != NULL) i_stream_unref(&parser->input); } void http_message_parser_restart(struct http_message_parser *parser, pool_t pool) { i_assert(parser->payload == NULL); if (parser->header_parser == NULL) { parser->header_parser = http_header_parser_init (parser->input, &parser->header_limits, parser->lenient); } else { http_header_parser_reset(parser->header_parser); } if (parser->msg.pool != NULL) pool_unref(&parser->msg.pool); i_zero(&parser->msg); if (pool == NULL) { parser->msg.pool = pool_alloconly_create("http_message", 4096); } else { parser->msg.pool = pool; pool_ref(pool); } parser->msg.date = (time_t)-1; parser->msg.header = http_header_create(parser->msg.pool, 32); } int http_message_parse_version(struct http_message_parser *parser) { const unsigned char *p = parser->cur; const size_t size = parser->end - parser->cur; parser->error_code = HTTP_MESSAGE_PARSE_ERROR_NONE; parser->error = NULL; /* RFC 7230, Section 2.6: Protocol Versioning HTTP-version = HTTP-name "/" DIGIT "." DIGIT HTTP-name = %x48.54.54.50 ; "HTTP", case-sensitive */ if (size < 8) return 0; if (memcmp(p, "HTTP/", 5) != 0 || !i_isdigit(p[5]) || p[6] != '.' || !i_isdigit(p[7])) { parser->error = "Bad HTTP version"; parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_MESSAGE; return -1; } parser->msg.version_major = p[5] - '0'; parser->msg.version_minor = p[7] - '0'; parser->cur += 8; return 1; } int http_message_parse_finish_payload(struct http_message_parser *parser) { const unsigned char *data; size_t size; int ret; parser->error_code = HTTP_MESSAGE_PARSE_ERROR_NONE; parser->error = NULL; if (parser->payload == NULL) return 1; while ((ret = i_stream_read_data(parser->payload, &data, &size, 0)) > 0) i_stream_skip(parser->payload, size); if (ret == 0 || parser->payload->stream_errno != 0) { if (ret < 0) { if (parser->payload->stream_errno == EMSGSIZE) { parser->error_code = HTTP_MESSAGE_PARSE_ERROR_PAYLOAD_TOO_LARGE; parser->error = "Payload is too large"; } else if (parser->payload->stream_errno == EIO) { parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_MESSAGE; parser->error = "Invalid payload"; } else { parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_STREAM; parser->error = "Stream error while skipping payload"; } } return ret; } i_stream_destroy(&parser->payload); return 1; } static int http_message_parse_header(struct http_message_parser *parser, const char *name, const unsigned char *data, size_t size) { const struct http_header_field *hdr; struct http_parser hparser; hdr = http_header_field_add(parser->msg.header, name, data, size); /* RFC 7230, Section 3.2.2: Field Order A sender MUST NOT generate multiple header fields with the same field name in a message unless either the entire field value for that header field is defined as a comma-separated list [i.e., #(values)] or the header field is a well-known exception. */ switch (name[0]) { case 'C': case 'c': /* Connection: */ if (strcasecmp(name, "Connection") == 0) { const char **opt_idx; const char *option; unsigned int num_tokens = 0; /* RFC 7230, Section 6.1: Connection Connection = 1#connection-option connection-option = token */ /* Multiple Connection headers are allowed and combined into one */ http_parser_init(&hparser, data, size); for (;;) { if (http_parse_token_list_next(&hparser, &option) <= 0) break; num_tokens++; if (strcasecmp(option, "close") == 0) parser->msg.connection_close = TRUE; if (!array_is_created(&parser->msg.connection_options)) p_array_init(&parser->msg.connection_options, parser->msg.pool, 4); opt_idx = array_append_space(&parser->msg.connection_options); *opt_idx = p_strdup(parser->msg.pool, option); } if (hparser.cur < hparser.end || num_tokens == 0) { parser->error = "Invalid Connection header"; parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_MESSAGE; return -1; } return 0; } /* Content-Length: */ if (strcasecmp(name, "Content-Length") == 0) { if (parser->msg.have_content_length) { parser->error = "Duplicate Content-Length header"; parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_MESSAGE; return -1; } /* RFC 7230, Section 3.3.2: Content-Length Content-Length = 1*DIGIT */ if (str_to_uoff(hdr->value, &parser->msg.content_length) < 0) { parser->error= "Invalid Content-Length header"; parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_MESSAGE; return -1; } parser->msg.have_content_length = TRUE; return 0; } break; case 'D': case 'd': /* Date: */ if (strcasecmp(name, "Date") == 0) { if (parser->msg.date != (time_t)-1) { parser->error = "Duplicate Date header"; parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_MESSAGE; return -1; } /* RFC 7231, Section 7.1.1.2: Date Date = HTTP-date */ (void)http_date_parse(data, size, &parser->msg.date); return 0; } break; case 'L': case 'l': /* Location: */ if (strcasecmp(name, "Location") == 0) { /* RFC 7231, Section 7.1.2: Location Location = URI-reference -> not parsed here */ /* FIXME: move this to response parser */ parser->msg.location = hdr->value; return 0; } break; case 'T': case 't': /* Transfer-Encoding: */ if (strcasecmp(name, "Transfer-Encoding") == 0) { const char *trenc = NULL; /* Multiple Transfer-Encoding headers are allowed and combined into one */ if (!array_is_created(&parser->msg.transfer_encoding)) p_array_init(&parser->msg.transfer_encoding, parser->msg.pool, 4); /* RFC 7230, Section 3.3.1: Transfer-Encoding Transfer-Encoding = 1#transfer-coding RFC 7230, Section 4: Transfer Codings transfer-coding = "chunked" ; RFC 7230, Section 4.1 / "compress" ; RFC 7230, Section 4.2.1 / "deflate" ; RFC 7230, Section 4.2.2 / "gzip" ; RFC 7230, Section 4.2.3 / transfer-extension transfer-extension = token *( OWS ";" OWS transfer-parameter ) transfer-parameter = token BWS "=" BWS ( token / quoted-string ) */ http_parser_init(&hparser, data, size); for (;;) { /* transfer-coding */ if (http_parse_token(&hparser, &trenc) > 0) { struct http_transfer_coding *coding; bool parse_error; coding = array_append_space(&parser->msg.transfer_encoding); coding->name = p_strdup(parser->msg.pool, trenc); /* *( OWS ";" OWS transfer-parameter ) */ parse_error = FALSE; for (;;) { struct http_transfer_param *param; const char *attribute, *value; /* OWS ";" OWS */ http_parse_ows(&hparser); if (hparser.cur >= hparser.end || *hparser.cur != ';') break; hparser.cur++; http_parse_ows(&hparser); /* attribute */ if (http_parse_token(&hparser, &attribute) <= 0) { parse_error = TRUE; break; } /* BWS "=" BWS */ http_parse_ows(&hparser); if (hparser.cur >= hparser.end || *hparser.cur != '=') { parse_error = TRUE; break; } hparser.cur++; http_parse_ows(&hparser); /* token / quoted-string */ if (http_parse_token_or_qstring(&hparser, &value) <= 0) { parse_error = TRUE; break; } if (!array_is_created(&coding->parameters)) p_array_init(&coding->parameters, parser->msg.pool, 2); param = array_append_space(&coding->parameters); param->attribute = p_strdup(parser->msg.pool, attribute); param->value = p_strdup(parser->msg.pool, value); } if (parse_error) break; } else { /* RFC 7230, Section 7: ABNF List Extension: #rule For compatibility with legacy list rules, a recipient MUST parse and ignore a reasonable number of empty list elements: enough to handle common mistakes by senders that merge values, but not so much that they could be used as a denial-of-service mechanism. */ // FIXME: limit allowed number of empty list elements // FIXME: handle invalid transfer encoding } http_parse_ows(&hparser); if (hparser.cur >= hparser.end || *hparser.cur != ',') break; hparser.cur++; http_parse_ows(&hparser); } if (hparser.cur < hparser.end || array_count(&parser->msg.transfer_encoding) == 0) { parser->error = "Invalid Transfer-Encoding header"; parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_MESSAGE; return -1; } return 0; } break; default: break; } return 0; } int http_message_parse_headers(struct http_message_parser *parser) { const unsigned char *field_data; struct http_message *msg = &parser->msg; const char *field_name, *error; size_t field_size; int ret; parser->error_code = HTTP_MESSAGE_PARSE_ERROR_NONE; parser->error = NULL; /* *( header-field CRLF ) CRLF */ while ((ret=http_header_parse_next_field(parser->header_parser, &field_name, &field_data, &field_size, &error)) > 0) { if (field_name == NULL) { /* EOH */ /* handle HTTP/1.0 persistence */ if (msg->version_major == 1 && msg->version_minor == 0 && !msg->connection_close) { const char *const *option; msg->connection_close = TRUE; if (array_is_created(&parser->msg.connection_options)) { array_foreach(&msg->connection_options, option) { if (strcasecmp(*option, "Keep-Alive") == 0) { msg->connection_close = FALSE; break; } } } } return 1; } if (http_message_parse_header(parser, field_name, field_data, field_size) < 0) return -1; } if (ret < 0) { if (parser->input->eof || parser->input->stream_errno != 0) { parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_STREAM; parser->error = "Broken stream"; } else { parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_MESSAGE; parser->error = t_strdup_printf("Failed to parse header: %s", error); } } return ret; } static const char * http_istream_error_callback(const struct istream_sized_error_data *data, struct istream *input) { i_assert(data->eof); i_assert(data->v_offset + data->new_bytes < data->wanted_size); return t_strdup_printf("Disconnected while reading response payload at offset %"PRIuUOFF_T " (wanted %"PRIuUOFF_T"): %s", data->v_offset + data->new_bytes, data->wanted_size, io_stream_get_disconnect_reason(input, NULL)); } int http_message_parse_body(struct http_message_parser *parser, bool request) { struct istream *input; i_assert(parser->payload == NULL); parser->error_code = HTTP_MESSAGE_PARSE_ERROR_NONE; parser->error = NULL; if (array_is_created(&parser->msg.transfer_encoding)) { const struct http_transfer_coding *coding; bool chunked_last = FALSE; array_foreach(&parser->msg.transfer_encoding, coding) { if (strcasecmp(coding->name, "chunked") == 0) { chunked_last = TRUE; if ((parser->error_code == HTTP_MESSAGE_PARSE_ERROR_NONE) && array_is_created(&coding->parameters) && array_count(&coding->parameters) > 0) { const struct http_transfer_param *param = array_idx(&coding->parameters, 0); parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BAD_MESSAGE; parser->error = t_strdup_printf( "Unexpected parameter `%s' specified" "for the `%s' transfer coding", param->attribute, coding->name); /* recoverable */ } } else if (chunked_last) { parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_MESSAGE; parser->error = "Chunked Transfer-Encoding must be last"; return -1; } else if (parser->error_code == HTTP_MESSAGE_PARSE_ERROR_NONE) { parser->error_code = HTTP_MESSAGE_PARSE_ERROR_NOT_IMPLEMENTED; parser->error = t_strdup_printf( "Unknown transfer coding `%s'", coding->name); /* recoverable */ } } if (chunked_last) { parser->payload = http_transfer_chunked_istream_create (parser->input, parser->max_payload_size); } else if (!request) { /* RFC 7230, Section 3.3.3: Message Body Length If a Transfer-Encoding header field is present in a response and the chunked transfer coding is not the final encoding, the message body length is determined by reading the connection until it is closed by the server. */ /* FIXME: enforce max payload size (relevant to http-client only) */ parser->payload = i_stream_create_limit(parser->input, (size_t)-1); } else { /* RFC 7230, Section 3.3.3: Message Body Length If a Transfer-Encoding header field is present in a request and the chunked transfer coding is not the final encoding, the message body length cannot be determined reliably; the server MUST respond with the 400 (Bad Request) status code and then close the connection. */ parser->error_code = HTTP_MESSAGE_PARSE_ERROR_BROKEN_MESSAGE; parser->error = "Final Transfer-Encoding in request is not chunked"; return -1; } /* RFC 7230, Section 3.3.3: Message Body Length If a message is received with both a Transfer-Encoding and a Content-Length header field, the Transfer-Encoding overrides the Content-Length. Such a message might indicate an attempt to perform request smuggling (Section 9.5 of [RFC7230]) or response splitting (Section 9.4 of [RFC7230]) and ought to be handled as an error. A sender MUST remove the received Content-Length field prior to forwarding such a message downstream. */ // FIXME: make this an error? if (parser->msg.have_content_length) http_header_field_delete(parser->msg.header, "Content-Length"); } else if (parser->msg.content_length > 0) { if (parser->max_payload_size > 0 && parser->msg.content_length > parser->max_payload_size) { parser->error_code = HTTP_MESSAGE_PARSE_ERROR_PAYLOAD_TOO_LARGE; parser->error = "Payload is too large"; return -1; } /* Got explicit message size from Content-Length: header */ input = i_stream_create_limit(parser->input, parser->msg.content_length); /* Make sure we return failure if HTTP connection closes before we've finished reading the full input. */ parser->payload = i_stream_create_sized_with_callback(input, parser->msg.content_length, http_istream_error_callback, input); i_stream_unref(&input); } else if (!parser->msg.have_content_length && !request) { /* RFC 7230, Section 3.3.3: Message Body Length 6. If this is a request message and none of the above are true, then the message body length is zero (no message body is present). 7. Otherwise, this is a response message without a declared message body length, so the message body length is determined by the number of octets received prior to the server closing the connection */ // FIXME: enforce max payload size (relevant to http-client only) // FIXME: handle request case correctly. parser->payload = i_stream_create_limit(parser->input, (size_t)-1); } if (parser->error_code != HTTP_MESSAGE_PARSE_ERROR_NONE) return -1; return 0; }