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exportfs: fix endless loop for eof/error on second read in localread9pmsg()

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the ini buffer was not reset when we got eof in the message
body read causing a endless loop. instead of defining our
own read9pmsg() function, just handle the first read specially
when we consumed the first 4 bytes for the "impo" protocol
escape check.
This commit is contained in:
cinap_lenrek 2016-02-21 20:11:04 +01:00
parent 688c1f15cd
commit 046e0ee259
1 changed files with 16 additions and 40 deletions
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56
sys/src/cmd/exportfs/exportfs.c
View file

@ -51,7 +51,6 @@ int encproto = Encnone;
int readonly;
static void mksecret(char *, uchar *);
static int localread9pmsg(int, void *, uint, void *);
static char *anstring = "tcp!*!0";
char *netdir = "", *local = "", *remote = "";
@ -391,60 +390,37 @@ main(int argc, char **argv)
if(ai != nil)
auth_freeAI(ai);
if(ini != nil){
r = getsbuf();
memmove(r->buf, ini, BIT32SZ);
n = GBIT32(r->buf);
if(n <= BIT32SZ || n > messagesize)
fatal("bad length in 9P2000 message header");
n -= BIT32SZ;
if(readn(0, r->buf+BIT32SZ, n) != n)
fatal(nil);
n += BIT32SZ;
goto Message;
}
/*
* Start serving file requests from the network
*/
for(;;) {
r = getsbuf();
while((n = localread9pmsg(0, r->buf, messagesize, ini)) == 0)
while((n = read9pmsg(0, r->buf, messagesize)) == 0)
;
if(n < 0)
if(n <= 0)
fatal(nil);
Message:
if(convM2S(r->buf, n, &r->work) == 0)
fatal("convM2S format error");
DEBUG(DFD, "%F\n", &r->work);
(fcalls[r->work.type])(r);
ini = nil;
}
}
/*
* WARNING: Replace this with the original version as soon as all
* _old_ imports have been replaced with negotiating imports. Also
* cpu relies on this (which needs to be fixed!) -- pb.
*/
static int
localread9pmsg(int fd, void *abuf, uint n, void *ini)
{
int m, len;
uchar *buf;
buf = abuf;
/* read count */
if(ini != nil)
memcpy(buf, ini, BIT32SZ);
else {
m = readn(fd, buf, BIT32SZ);
if(m != BIT32SZ){
if(m < 0)
return -1;
return 0;
}
}
len = GBIT32(buf);
if(len <= BIT32SZ || len > n){
werrstr("bad length in 9P2000 message header");
return -1;
}
len -= BIT32SZ;
m = readn(fd, buf+BIT32SZ, len);
if(m < len)
return 0;
return BIT32SZ+m;
}
void
reply(Fcall *r, Fcall *t, char *err)
{