jonathan@comp.vuw.ac.nz (Jonathan) (09/04/88)
Symptom:
Any calls to clnt_broadcast() fail on 4.3bsd with error
message "Cannot send broadcast packet: Permission denied",
even for the super-user.
On Pyramid OSx 4.0, clnt_broadcast() succeeds, but
no broadcast UDP packet leaves the local machine.
Repeat_By:
The broadcast RPC example from the manual is
probably sufficient.
Diagnosis:
On 4.3bsd systems, a socket must be setsockopt()'ed
SO_BROADCAST before it can be used for broadcast.
SunRPC 3.9 doesn't, causing sendto() to return EACCESS.
Fix:
For 4.3bsd systems, apply the following context diff.
It can easily be made applicable to other 4.3bsd-derived
systems (eg, OSx 4.0), if you are prepared to replace the
vendor's definition of clnt_broadcast() with the patched
SunRPC 3.9 source.
I don't know what the effect on non-bsd systems is.
*** pmap_rmt.c Sun Sep 4 14:29:24 1988
--- pmap_rmt.bsdfix.c Sun Sep 4 14:28:11 1988
***************
*** 52,57 ****
--- 52,59 ----
#include <arpa/inet.h>
#define MAX_BROADCAST_SIZE 1400
+ #include <sys/param.h>
+
extern int errno;
static struct timeval timeout = { 3, 0 };
***************
*** 241,246 ****
--- 243,249 ----
struct rpc_msg msg;
struct timeval t;
char outbuf[MAX_BROADCAST_SIZE], inbuf[UDPMSGSIZE];
+ int brdcst_enbl =1;
/*
* initialization: create a socket, a broadcast address, and
***************
*** 262,267 ****
--- 265,279 ----
baddr.sin_family = AF_INET;
baddr.sin_port = htons(PMAPPORT);
baddr.sin_addr.s_addr = htonl(INADDR_ANY);
+
+ #ifdef BSD4_3
+ if (setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &brdcst_enbl, sizeof (brdcst_enbl)) < 0) {
+ perror("Broadcast authorization problem");
+ stat = RPC_CANTSEND;
+ goto done_broad;
+ }
+ #endif BSD4_3
+
/* baddr.sin_addr.S_un.S_addr = htonl(INADDR_ANY); */
(void)gettimeofday(&t, (struct timezone *)0);
msg.rm_xid = xid = getpid() ^ t.tv_sec ^ t.tv_usec;
--
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