Hi linux-il colleagues,
In >= 2.6.31 are there any conditions under which a write to a connected
UDP socket can block? e.g. some change in routing or iface config after
connect and before write? Has anyone encountered a concrete exampe of a
write to a UDP socket that blocks? See test code below. That is, I am
trying to demonstrate that I can get to a situation where UDP write in
fact does block.
Best regards,
- yba
#include <stdio.h>
#include <strings.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <net/if.h>
#include <stdlib.h>
#include <errno.h>
int main()
{
int sd;
int rc;
struct ifreq interface;
struct sockaddr_in sin;
unsigned char buf[1024];
struct sockaddr_in serveraddr;
if (0 > (sd = socket(AF_INET, SOCK_DGRAM, 0))) {
printf("socket failed\n");
exit(1);
}
sin.sin_family = AF_INET;
sin.sin_port = htons(0);
bzero(&(sin.sin_zero), 8);
sin.sin_addr.s_addr = INADDR_ANY;
if (-1 == bind(sd, (struct sockaddr *)&sin, sizeof(struct
sockaddr_in))) {
printf("bind to sd failed [%m]");
return -1;
}
bzero(&serveraddr, sizeof(struct sockaddr_in));
serveraddr.sin_family = AF_INET;
serveraddr.sin_port = htons(80);
inet_pton(AF_INET, "1.0.1.2", &serveraddr.sin_addr);
if (0 > (rc = connect(sd, (const struct sockaddr*)&serveraddr,
sizeof(serveraddr)))) {
printf("connect failed [%m]");
exit(1);
}
while ( 1 ) {
if (0 > (rc = write(sd, buf, 1024))) {
printf("write error [%m]\n");
}
else
printf("wrote to socket [%d]\n", rc);
}
}
--
EE 77 7F 30 4A 64 2E C5 83 5F E7 49 A6 82 29 BA ~. .~ Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
- y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
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