Pi-Hole/dnsmasq
1
0
Fork 0
mirror of https://github.com/pi-hole/dnsmasq.git synced 2025-12-19 10:18:25 +00:00
Code Issues Packages Projects Releases Wiki Activity

Handle UDP packet loss when fragmentation of large packets is broken.

Browse Source
This commit is contained in:
Simon Kelley
2015-05-08 16:25:38 +01:00
parent 64bcff1c7c
commit a77cec8d58
8 changed files with 66 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
src/rfc1035.c
View File

@@ -552,7 +552,7 @@ static size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned
return plen;
*p++ = 0; /* empty name */
PUTSHORT(T_OPT, p);
PUTSHORT(daemon->edns_pktsz, p); /* max packet length */
PUTSHORT(SAFE_PKTSZ, p); /* max packet length, this will be overwritten */
PUTSHORT(0, p); /* extended RCODE and version */
PUTSHORT(set_do ? 0x8000 : 0, p); /* DO flag */
lenp = p;
@@ -1537,7 +1537,6 @@ size_t answer_request(struct dns_header *header, char *limit, size_t qlen,
unsigned short flag;
int q, ans, anscount = 0, addncount = 0;
int dryrun = 0, sec_reqd = 0, have_pseudoheader = 0;
int is_sign;
struct crec *crecp;
int nxdomain = 0, auth = 1, trunc = 0, sec_data = 1;
struct mx_srv_record *rec;
@@ -1557,28 +1556,19 @@ size_t answer_request(struct dns_header *header, char *limit, size_t qlen,
forward rather than answering from the cache, which doesn't include
security information, unless we're in DNSSEC validation mode. */
if (find_pseudoheader(header, qlen, NULL, &pheader, &is_sign))
if (find_pseudoheader(header, qlen, NULL, &pheader, NULL))
{
unsigned short udpsz, flags;
unsigned char *psave = pheader;
unsigned short flags;
have_pseudoheader = 1;
GETSHORT(udpsz, pheader);
pheader += 2; /* ext_rcode */
pheader += 4; /* udp size, ext_rcode */
GETSHORT(flags, pheader);
if ((sec_reqd = flags & 0x8000))
*do_bit = 1;/* do bit */
*ad_reqd = 1;
/* If our client is advertising a larger UDP packet size
than we allow, trim it so that we don't get an overlarge
response from upstream */
if (!is_sign && (udpsz > daemon->edns_pktsz))
PUTSHORT(daemon->edns_pktsz, psave);
dryrun = 1;
}