Break connection_dir_client_reached_eof() into smaller functions

This was a >630-line function, which doesn't make anybody happy.  It
was also mostly composed of a bunch of if-statements that handled
different directory responses differently depending on the original
purpose of the directory connection.  The logical refactoring here
is to move the body of each switch statement into a separate handler
function, and to invoke those functions from a separate switch
statement.

This commit leaves whitespace mostly untouched, for ease of review.
I'll reindent in the next commit.
This commit is contained in:
Nick Mathewson 2017-05-02 13:06:25 -04:00
parent fd437f2a02
commit db86b9194d
2 changed files with 286 additions and 38 deletions

View File

@ -0,0 +1,5 @@
o Code simplification and refactoring:
- Break up the 630-line function connection_dir_client_reached_eof() into
a dozen smaller functions. This change should help maintainability and
readability of the client directory code.

View File

@ -2073,6 +2073,39 @@ load_downloaded_routers(const char *body, smartlist_t *which,
return added;
}
/** A structure to hold arguments passed into each directory response
* handler */
typedef struct response_handler_args_t {
int status_code;
const char *reason;
const char *body;
size_t body_len;
const char *headers;
} response_handler_args_t;
static int handle_response_fetch_consensus(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_certificate(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_status_vote(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_detached_signatures(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_desc(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_microdesc(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_upload_dir(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_upload_vote(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_upload_signatures(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_renddesc_v2(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_upload_renddesc_v2(dir_connection_t *,
const response_handler_args_t *);
/** We are a client, and we've finished reading the server's
* response. Parse it and act appropriately.
*
@ -2098,8 +2131,6 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
int allow_partial = (conn->base_.purpose == DIR_PURPOSE_FETCH_SERVERDESC ||
conn->base_.purpose == DIR_PURPOSE_FETCH_EXTRAINFO ||
conn->base_.purpose == DIR_PURPOSE_FETCH_MICRODESC);
time_t now = time(NULL);
int src_code;
size_t received_bytes;
received_bytes = connection_get_inbuf_len(TO_CONN(conn));
@ -2193,6 +2224,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
"'%s:%d'. I'll try again soon.",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
time_t now = approx_time();
if ((rs = router_get_mutable_consensus_status_by_id(id_digest)))
rs->last_dir_503_at = now;
if ((ds = router_get_fallback_dirserver_by_digest(id_digest)))
@ -2260,7 +2292,77 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
}
}
if (conn->base_.purpose == DIR_PURPOSE_FETCH_CONSENSUS) {
int rv;
response_handler_args_t args;
memset(&args, 0, sizeof(args));
args.status_code = status_code;
args.reason = reason;
args.body = body;
args.body_len = body_len;
args.headers = headers;
switch (conn->base_.purpose) {
case DIR_PURPOSE_FETCH_CONSENSUS:
rv = handle_response_fetch_consensus(conn, &args);
break;
case DIR_PURPOSE_FETCH_CERTIFICATE:
rv = handle_response_fetch_certificate(conn, &args);
break;
case DIR_PURPOSE_FETCH_STATUS_VOTE:
rv = handle_response_fetch_status_vote(conn, &args);
break;
case DIR_PURPOSE_FETCH_DETACHED_SIGNATURES:
rv = handle_response_fetch_detached_signatures(conn, &args);
break;
case DIR_PURPOSE_FETCH_SERVERDESC:
case DIR_PURPOSE_FETCH_EXTRAINFO:
rv = handle_response_fetch_desc(conn, &args);
break;
case DIR_PURPOSE_FETCH_MICRODESC:
rv = handle_response_fetch_microdesc(conn, &args);
break;
case DIR_PURPOSE_FETCH_RENDDESC_V2:
rv = handle_response_fetch_renddesc_v2(conn, &args);
break;
case DIR_PURPOSE_UPLOAD_DIR:
rv = handle_response_upload_dir(conn, &args);
break;
case DIR_PURPOSE_UPLOAD_SIGNATURES:
rv = handle_response_upload_signatures(conn, &args);
break;
case DIR_PURPOSE_UPLOAD_VOTE:
rv = handle_response_upload_vote(conn, &args);
break;
case DIR_PURPOSE_UPLOAD_RENDDESC_V2:
rv = handle_response_upload_renddesc_v2(conn, &args);
break;
default:
tor_assert_nonfatal_unreached();
rv = -1;
break;
}
tor_free(body);
tor_free(headers);
tor_free(reason);
return rv;
}
/**
* Handler function: processes a response to a request for a networkstatus
* consensus document by checking the consensus, storing it, and marking
* router requests as reachable.
**/
static int
handle_response_fetch_consensus(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_CONSENSUS);
const int status_code = args->status_code;
const char *body = args->body;
const size_t body_len = args->body_len;
const char *reason = args->reason;
const time_t now = approx_time();
int r;
const char *flavname = conn->requested_resource;
if (status_code != 200) {
@ -2270,7 +2372,6 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
"'%s:%d' while fetching consensus directory.",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
tor_free(body); tor_free(headers); tor_free(reason);
networkstatus_consensus_download_failed(status_code, flavname);
return -1;
}
@ -2282,7 +2383,6 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
"Unable to load %s consensus directory downloaded from "
"server '%s:%d'. I'll try again soon.",
flavname, conn->base_.address, conn->base_.port);
tor_free(body); tor_free(headers); tor_free(reason);
networkstatus_consensus_download_failed(0, flavname);
return -1;
}
@ -2300,17 +2400,31 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
networkstatus_get_latest_consensus_by_flavor(FLAV_NS));
}
log_info(LD_DIR, "Successfully loaded consensus.");
}
if (conn->base_.purpose == DIR_PURPOSE_FETCH_CERTIFICATE) {
if (status_code != 200) {
return 0;
}
/**
* Handler function: processes a response to a request for one or more
* authority certificates
**/
static int
handle_response_fetch_certificate(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_CERTIFICATE);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
if (status_code != 200) {
log_warn(LD_DIR,
"Received http status code %d (%s) from server "
"'%s:%d' while fetching \"/tor/keys/%s\".",
status_code, escaped(reason), conn->base_.address,
conn->base_.port, conn->requested_resource);
connection_dir_download_cert_failed(conn, status_code);
tor_free(body); tor_free(headers); tor_free(reason);
return -1;
}
log_info(LD_DIR,"Received authority certificates (body size %d) from "
@ -2321,7 +2435,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
* Tell trusted_dirs_load_certs_from_string() whether it was by fp
* or fp-sk pair.
*/
src_code = -1;
int src_code = -1;
if (!strcmpstart(conn->requested_resource, "fp/")) {
src_code = TRUSTED_DIRS_CERTS_SRC_DL_BY_ID_DIGEST;
} else if (!strcmpstart(conn->requested_resource, "fp-sk/")) {
@ -2336,6 +2450,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
* ones got flushed to disk so it's safe to call this on them */
connection_dir_download_cert_failed(conn, status_code);
} else {
time_t now = approx_time();
directory_info_has_arrived(now, 0, 0);
log_info(LD_DIR, "Successfully loaded certificates from fetch.");
}
@ -2346,8 +2461,24 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
conn->requested_resource);
connection_dir_download_cert_failed(conn, status_code);
}
}
if (conn->base_.purpose == DIR_PURPOSE_FETCH_STATUS_VOTE) {
return 0;
}
/**
* Handler function: processes a response to a request for an authority's
* current networkstatus vote.
**/
static int
handle_response_fetch_status_vote(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_STATUS_VOTE);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
const char *msg;
int st;
log_info(LD_DIR,"Got votes (body size %d) from server %s:%d",
@ -2358,7 +2489,6 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
"'%s:%d' while fetching \"/tor/status-vote/next/%s.z\".",
status_code, escaped(reason), conn->base_.address,
conn->base_.port, conn->requested_resource);
tor_free(body); tor_free(headers); tor_free(reason);
return -1;
}
dirvote_add_vote(body, &msg, &st);
@ -2367,8 +2497,24 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
} else {
log_info(LD_DIR, "Added vote(s) successfully [msg: %s]", msg);
}
}
if (conn->base_.purpose == DIR_PURPOSE_FETCH_DETACHED_SIGNATURES) {
return 0;
}
/**
* Handler function: processes a response to a request for the signatures
* that an authority knows about on a given consensus.
**/
static int
handle_response_fetch_detached_signatures(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_DETACHED_SIGNATURES);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
const char *msg = NULL;
log_info(LD_DIR,"Got detached signatures (body size %d) from server %s:%d",
(int)body_len, conn->base_.address, conn->base_.port);
@ -2378,17 +2524,31 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
"\"/tor/status-vote/next/consensus-signatures.z\".",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
tor_free(body); tor_free(headers); tor_free(reason);
return -1;
}
if (dirvote_add_signatures(body, conn->base_.address, &msg)<0) {
log_warn(LD_DIR, "Problem adding detached signatures from %s:%d: %s",
conn->base_.address, conn->base_.port, msg?msg:"???");
}
}
if (conn->base_.purpose == DIR_PURPOSE_FETCH_SERVERDESC ||
conn->base_.purpose == DIR_PURPOSE_FETCH_EXTRAINFO) {
return 0;
}
/**
* Handler function: processes a response to a request for a group of server
* descriptors or an extrainfo documents.
**/
static int
handle_response_fetch_desc(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_SERVERDESC ||
conn->base_.purpose == DIR_PURPOSE_FETCH_EXTRAINFO);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
int was_ei = conn->base_.purpose == DIR_PURPOSE_FETCH_EXTRAINFO;
smartlist_t *which = NULL;
int n_asked_for = 0;
@ -2425,7 +2585,6 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
SMARTLIST_FOREACH(which, char *, cp, tor_free(cp));
smartlist_free(which);
}
tor_free(body); tor_free(headers); tor_free(reason);
return dir_okay ? 0 : -1;
}
/* Learn the routers, assuming we requested by fingerprint or "all"
@ -2449,8 +2608,10 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
// descriptor_digests, conn->router_purpose);
if (load_downloaded_routers(body, which, descriptor_digests,
conn->router_purpose,
conn->base_.address))
conn->base_.address)) {
time_t now = approx_time();
directory_info_has_arrived(now, 0, 0);
}
}
}
if (which) { /* mark remaining ones as failed */
@ -2468,8 +2629,24 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
}
if (directory_conn_is_self_reachability_test(conn))
router_dirport_found_reachable();
}
if (conn->base_.purpose == DIR_PURPOSE_FETCH_MICRODESC) {
return 0;
}
/**
* Handler function: processes a response to a request for a group of
* microdescriptors
**/
static int
handle_response_fetch_microdesc(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_MICRODESC);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
smartlist_t *which = NULL;
log_info(LD_DIR,"Received answer to microdescriptor request (status %d, "
"body size %d) from server '%s:%d'",
@ -2490,10 +2667,10 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
dir_microdesc_download_failed(which, status_code);
SMARTLIST_FOREACH(which, char *, cp, tor_free(cp));
smartlist_free(which);
tor_free(body); tor_free(headers); tor_free(reason);
return 0;
} else {
smartlist_t *mds;
time_t now = approx_time();
mds = microdescs_add_to_cache(get_microdesc_cache(),
body, body+body_len, SAVED_NOWHERE, 0,
now, which);
@ -2510,9 +2687,23 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
smartlist_free(which);
smartlist_free(mds);
}
}
if (conn->base_.purpose == DIR_PURPOSE_UPLOAD_DIR) {
return 0;
}
/**
* Handler function: processes a response to a POST request to upload our
* router descriptor.
**/
static int
handle_response_upload_dir(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_UPLOAD_DIR);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *headers = args->headers;
switch (status_code) {
case 200: {
dir_server_t *ds =
@ -2563,9 +2754,22 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
}
/* return 0 in all cases, since we don't want to mark any
* dirservers down just because they don't like us. */
}
if (conn->base_.purpose == DIR_PURPOSE_UPLOAD_VOTE) {
return 0;
}
/**
* Handler function: processes a response to POST request to upload our
* own networkstatus vote.
**/
static int
handle_response_upload_vote(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_UPLOAD_VOTE);
const int status_code = args->status_code;
const char *reason = args->reason;
switch (status_code) {
case 200: {
log_notice(LD_DIR,"Uploaded a vote to dirserver %s:%d",
@ -2587,9 +2791,21 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
}
/* return 0 in all cases, since we don't want to mark any
* dirservers down just because they don't like us. */
}
return 0;
}
/**
* Handler function: processes a response to POST request to upload our
* view of the signatures on the current consensus.
**/
static int
handle_response_upload_signatures(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_UPLOAD_SIGNATURES);
const int status_code = args->status_code;
const char *reason = args->reason;
if (conn->base_.purpose == DIR_PURPOSE_UPLOAD_SIGNATURES) {
switch (status_code) {
case 200: {
log_notice(LD_DIR,"Uploaded signature(s) to dirserver %s:%d",
@ -2611,10 +2827,25 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
}
/* return 0 in all cases, since we don't want to mark any
* dirservers down just because they don't like us. */
}
if (conn->base_.purpose == DIR_PURPOSE_FETCH_RENDDESC_V2) {
#define SEND_HS_DESC_FAILED_EVENT(reason) ( \
return 0;
}
/**
* Handler function: processes a response to a request for a v2 hidden service
* descriptor.
**/
static int
handle_response_fetch_renddesc_v2(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_RENDDESC_V2);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
#define SEND_HS_DESC_FAILED_EVENT(reason) ( \
control_event_hs_descriptor_failed(conn->rend_data, \
conn->identity_digest, \
reason) )
@ -2689,10 +2920,23 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
SEND_HS_DESC_FAILED_CONTENT();
break;
}
}
if (conn->base_.purpose == DIR_PURPOSE_UPLOAD_RENDDESC_V2) {
#define SEND_HS_DESC_UPLOAD_FAILED_EVENT(reason) ( \
return 0;
}
/**
* Handler function: processes a response to a POST request to upload a v2
* hidden service descriptor.
**/
static int
handle_response_upload_renddesc_v2(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_UPLOAD_RENDDESC_V2);
const int status_code = args->status_code;
const char *reason = args->reason;
#define SEND_HS_DESC_UPLOAD_FAILED_EVENT(reason) ( \
control_event_hs_descriptor_upload_failed( \
conn->identity_digest, \
rend_data_get_address(conn->rend_data), \
@ -2726,8 +2970,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
SEND_HS_DESC_UPLOAD_FAILED_EVENT("UNEXPECTED");
break;
}
}
tor_free(body); tor_free(headers); tor_free(reason);
return 0;
}