[ZOOKEEPER-3426] ZK prime_connection(the Handshake) can complete without reading all the payload.

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 3.7.0
• Component/s: c client
• Labels: pull-request-available
• Assignee: Damien Diederen
• Reporter: Suhas Dantkale
• Created: 11/Jun/19 19:11
• Updated: 28/Mar/21 08:55
• Resolved: 13/Jan/21 08:29

Description

/* returns:

• -1 if recv call failed,

• 0 if recv would block,

• 1 if success

*/

static int recv_buffer(zhandle_t *zh, buffer_list_t *buff)

{

int off = buff->curr_offset;

int rc = 0;

[................]

if (buff == &zh->primer_buffer && rc == buff->len - 1) ++rc; <====== Handshake prematurely complete.

On non-blocking socket, it's possible that socket has exactly "buff->len - 1" bytes to read.
Because of the above line, the Handshake is prematurely completed.
What this can lead to is:
There will be one outstanding byte left on the socket and it might go as part of next message which could get corrupted.

I think this can lead to ZRUNTIMEINCONSISTENCY issues later.

Issue Links

• links to: GitHub Pull Request #1576