commit fd48b757d3a85099057d27a74555d87fcd33936e Author: Nick Mathewson nickm@torproject.org Date: Tue Apr 25 16:44:24 2017 -0400

Parse recognized entries from the Accept-Encoding header. --- src/or/directory.c | 59 ++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 48 insertions(+), 11 deletions(-)

diff --git a/src/or/directory.c b/src/or/directory.c index e0409e2..8229279 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -2789,6 +2789,31 @@ write_http_response_header(dir_connection_t *conn, ssize_t length, cache_lifetime); }

+/** Parse the compression methods listed in an Accept-Encoding header <b>h</b>, + * and convert them to a bitfield where compression method x is supported if + * and only if 1 &lt;&lt; x is set in the bitfield. */ +static unsigned +parse_accept_encoding_header(const char *h) +{ + unsigned result = (1u << NO_METHOD); + smartlist_t *methods = smartlist_new(); + smartlist_split_string(methods, h, ",", + SPLIT_SKIP_SPACE|SPLIT_STRIP_SPACE|SPLIT_IGNORE_BLANK, 0); + + SMARTLIST_FOREACH_BEGIN(methods, const char *, m) { + compress_method_t method = compression_method_get_by_name(m); + if (method != UNKNOWN_METHOD) { + tor_assert(method < 8*sizeof(unsigned)); + result |= (1u << method); + } + } SMARTLIST_FOREACH_END(m); + SMARTLIST_FOREACH_BEGIN(methods, char *, m) { + tor_free(m); + } SMARTLIST_FOREACH_END(m); + smartlist_free(methods); + return result; +} + /** Decide whether a client would accept the consensus we have. * * Clients can say they only want a consensus if it's signed by more @@ -2863,8 +2888,9 @@ choose_compression_level(ssize_t n_bytes)

/** Information passed to handle a GET request. */ typedef struct get_handler_args_t { - /** True if the client asked for compressed data. */ - int compressed; + /** Bitmask of compression methods that the client said (or implied) it + * supported. */ + unsigned compression_supported; /** If nonzero, the time included an if-modified-since header with this * value. */ time_t if_modified_since; @@ -2938,8 +2964,9 @@ directory_handle_command_get,(dir_connection_t *conn, const char *headers, { char *url, *url_mem, *header; time_t if_modified_since = 0; - int compressed; + int zlib_compressed_in_url; size_t url_len; + unsigned compression_methods_supported;

/* We ignore the body of a GET request. */ (void)req_body; @@ -2970,17 +2997,27 @@ directory_handle_command_get,(dir_connection_t *conn, const char *headers,

url_mem = url; url_len = strlen(url); - compressed = url_len > 2 && !strcmp(url+url_len-2, ".z"); - if (compressed) { + + zlib_compressed_in_url = url_len > 2 && !strcmp(url+url_len-2, ".z"); + if (zlib_compressed_in_url) { url[url_len-2] = '\0'; url_len -= 2; }

+ if ((header = http_get_header(headers, "Accept-Encoding"))) { + compression_methods_supported = parse_accept_encoding_header(header); + tor_free(header); + } else { + compression_methods_supported = (1u << NO_METHOD); + if (zlib_compressed_in_url) + compression_methods_supported |= (1u << ZLIB_METHOD); + } + get_handler_args_t args; args.url = url; args.headers = headers; args.if_modified_since = if_modified_since; - args.compressed = compressed; + args.compression_supported = compression_methods_supported;

int i, result = -1; for (i = 0; url_table[i].string; ++i) { @@ -3059,7 +3096,7 @@ handle_get_current_consensus(dir_connection_t *conn, const get_handler_args_t *args) { const char *url = args->url; - const int compressed = args->compressed; + const int compressed = args->compression_supported & (1u << ZLIB_METHOD); const time_t if_modified_since = args->if_modified_since; int clear_spool = 0;

@@ -3200,7 +3237,7 @@ static int handle_get_status_vote(dir_connection_t *conn, const get_handler_args_t *args) { const char *url = args->url; - const int compressed = args->compressed; + const int compressed = args->compression_supported & (1u << ZLIB_METHOD); { int current; ssize_t body_len = 0; @@ -3307,7 +3344,7 @@ static int handle_get_microdesc(dir_connection_t *conn, const get_handler_args_t *args) { const char *url = args->url; - const int compressed = args->compressed; + const int compressed = args->compression_supported & (1u << ZLIB_METHOD); int clear_spool = 1; { conn->spool = smartlist_new(); @@ -3357,7 +3394,7 @@ static int handle_get_descriptor(dir_connection_t *conn, const get_handler_args_t *args) { const char *url = args->url; - const int compressed = args->compressed; + const int compressed = args->compression_supported & (1u << ZLIB_METHOD); const or_options_t *options = get_options(); int clear_spool = 1; if (!strcmpstart(url,"/tor/server/") || @@ -3450,7 +3487,7 @@ static int handle_get_keys(dir_connection_t *conn, const get_handler_args_t *args) { const char *url = args->url; - const int compressed = args->compressed; + const int compressed = args->compression_supported & (1u << ZLIB_METHOD); const time_t if_modified_since = args->if_modified_since; { smartlist_t *certs = smartlist_new();