Reusing linux abstract namespace socket - c

Question

I would like to reuse one abstract socket adress during one server session. I tried to close sockets and bind them again, but it isn't working.
server.c:
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
int main()
{
struct sockaddr_un workmanaddr;
workmanaddr.sun_family=AF_UNIX;
strcpy(workmanaddr.sun_path+1,"name");
workmanaddr.sun_path[0]='0';
char buf[255];
int sd = socket(AF_UNIX, SOCK_DGRAM, 0);
if(sd <0)
{
perror("socket() error");
exit(2);
}
if((bind(sd , (struct sockaddr *)&workmanaddr,sizeof(workmanaddr)))<0)
{
perror("bind() error");
exit(3);
}
while(true)
{
recv(sd, buf, sizeof(buf), 0);
printf("%s\n",buf);
close(sd);
sd = socket(AF_UNIX, SOCK_DGRAM, 0);
if(sd <0)
{
perror("socket() error");
exit(2);
}
if((bind(sd , (struct sockaddr*)&workmanaddr,sizeof(workmanaddr)))<0)
{
perror("bind() error");
exit(3);
}
}
return 0;
}
client.c:
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
int main(int argc, char *argv[])
{
char _path[108]="name";
struct sockaddr_un tempadres = {0};
int tmpsock;
tmpsock = socket(AF_UNIX, SOCK_DGRAM, 0);
if(tmpsock<0)
{
perror("socket() error");
exit(2);
}
tempadres.sun_family=AF_UNIX;
strcpy(tempadres.sun_path+1,_path);
tempadres.sun_path[0]='0';
if((connect(tmpsock, (struct sockaddr *)&tempadres,sizeof(tempadres)))<0)
{
perror("connect() error");
exit(3);
}
char buf[255];
scanf("%s",buf);
if(send(tmpsock, buf, sizeof(buf), 0)<0)
{
perror("send() error");
exit(4);
}
return 0;
}
What should I do to make it possible to reuse it many times? Any advices?

Answer 1

In this line: tempadres.sun_path[0]='0','0' is not null byte what abstract socket requires for the first byte of the sun_path field. So it wouldn't be regarded as abstract socket. Change it to tempadres.sun_path[0]=0 or tempadres.sun_path[0]='\0'.
PS: there is another problem in your server.c, you didn't zero out workmanaddr, so the sun_path is very likely to contain garbage value as it's allocated on the stack even though you called strcpy(workmanaddr.sun_path+1,"name"); and a null byte is appended because all the remaining bytes in sun_path define the "name" of the socket. it would lead to different socket names with the client, resulting in connection refused on client side.