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client: improve handling of unknown responses

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Rework the code to not ignore valid packets with unknown or obsolete
responses and return immediately with "bad reply from daemon" instead of
timing out with "cannot talk to daemon".
This commit is contained in:
Miroslav Lichvar 2018-03-06 11:48:44 +01:00
parent 499a69e611
commit 448ef779c2
1 changed files with 23 additions and 29 deletions
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52
client.c
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@ -1326,11 +1326,9 @@ static int proto_version = PROTO_VERSION_NUMBER;
static int
submit_request(CMD_Request *request, CMD_Reply *reply)
{
int bad_length, bad_sequence, bad_header;
int select_status;
int recv_status;
int read_length;
int expected_length;
int command_length;
int padding_length;
struct timespec ts_now, ts_start;
@ -1429,34 +1427,18 @@ submit_request(CMD_Request *request, CMD_Reply *reply)
DEBUG_LOG("Received %d bytes", recv_status);
read_length = recv_status;
if (read_length >= offsetof(CMD_Reply, data)) {
expected_length = PKL_ReplyLength(reply);
} else {
expected_length = 0;
}
bad_length = (read_length < expected_length ||
expected_length < offsetof(CMD_Reply, data));
if (!bad_length) {
bad_sequence = reply->sequence != request->sequence;
} else {
bad_sequence = 0;
}
if (bad_length || bad_sequence) {
continue;
}
bad_header = ((reply->version != proto_version &&
!(reply->version >= PROTO_VERSION_MISMATCH_COMPAT_CLIENT &&
ntohs(reply->status) == STT_BADPKTVERSION)) ||
(reply->pkt_type != PKT_TYPE_CMD_REPLY) ||
(reply->res1 != 0) ||
(reply->res2 != 0) ||
(reply->command != request->command));
if (bad_header) {
/* Check if the header is valid */
if (read_length < offsetof(CMD_Reply, data) ||
(reply->version != proto_version &&
!(reply->version >= PROTO_VERSION_MISMATCH_COMPAT_CLIENT &&
ntohs(reply->status) == STT_BADPKTVERSION)) ||
reply->pkt_type != PKT_TYPE_CMD_REPLY ||
reply->res1 != 0 ||
reply->res2 != 0 ||
reply->command != request->command ||
reply->sequence != request->sequence) {
DEBUG_LOG("Invalid reply");
continue;
}
@ -1475,6 +1457,15 @@ submit_request(CMD_Request *request, CMD_Reply *reply)
#error unknown compatibility with PROTO_VERSION - 1
#endif
/* Check that the packet contains all data it is supposed to have.
Unknown responses will always pass this test as their expected
length is zero. */
if (read_length < PKL_ReplyLength(reply)) {
DEBUG_LOG("Reply too short");
new_attempt = 1;
continue;
}
/* Good packet received, print out results */
DEBUG_LOG("Reply cmd=%d reply=%d stat=%d",
ntohs(reply->command), ntohs(reply->reply), ntohs(reply->status));
@ -1581,6 +1572,9 @@ request_reply(CMD_Request *request, CMD_Reply *reply, int requested_reply, int v
return 0;
}
/* Make sure an unknown response was not requested */
assert(PKL_ReplyLength(reply));
return 1;
}