Fixed handling dot stuffing in the DATA stage of the smtp chat

Signed-off-by: Janos SUTO <sj@acts.hu>
This commit is contained in:
Janos SUTO 2021-07-03 13:08:33 +02:00
parent 62fcb37606
commit 0b18c6060f

View File

@ -85,12 +85,21 @@ void process_data(struct smtp_session *session, char *buf, int buflen){
int written=0, n_writes=0;
while(written < buflen) {
int len = write(session->fd, buf+written, buflen-written);
// In the DATA phase skip the 1st character if it's a dot (.)
// and there are more characters before the trailing CR-LF
//
// See https://www.ietf.org/rfc/rfc5321.html#section-4.5.2 for more.
int dotstuff = 0;
if(*buf == '.' && buflen > 1 && *(buf+1) != '\r' && *(buf+1) != '\n') dotstuff = 1;
int len = write(session->fd, buf+dotstuff+written, buflen-dotstuff-written);
n_writes++;
if(len > 0){
if(len != buflen) syslog(LOG_PRIORITY, "WARN: partial write: %d/%d bytes (round: %d)", len, buflen, n_writes);
written += len;
if(len != buflen-dotstuff) syslog(LOG_PRIORITY, "WARN: partial write: %d/%d bytes (round: %d)", len, buflen-dotstuff, n_writes);
written += len + dotstuff;
session->tot_len += len;
}
else syslog(LOG_PRIORITY, "ERROR (line: %d) process_data(): written %d bytes", __LINE__, len);