static NetSocketState *net_socket_fd_init_dgram(VLANState *vlan, int fd, int is_connected) { struct sockaddr_in saddr; int newfd; socklen_t saddr_len; NetSocketState *s; /* fd passed: multicast: "learn" dgram_dst address from bound address and save it * Because this may be "shared" socket from a "master" process, datagrams would be recv() * by ONLY ONE process: we must "clone" this dgram socket --jjo */ if (is_connected) { if (getsockname(fd, (struct sockaddr *) &saddr, &saddr_len) == 0) { /* must be bound */ if (saddr.sin_addr.s_addr==0) { fprintf(stderr, "qemu: error: init_dgram: fd=%d unbound, cannot setup multicast dst addr\n", fd); return NULL; } /* clone dgram socket */ newfd = net_socket_mcast_create(&saddr); if (newfd < 0) { /* error already reported by net_socket_mcast_create() */ close(fd); return NULL; } /* clone newfd to fd, close newfd */ dup2(newfd, fd); close(newfd); } else { fprintf(stderr, "qemu: error: init_dgram: fd=%d failed getsockname(): %s\n", fd, strerror(errno)); return NULL; } } s = qemu_mallocz(sizeof(NetSocketState)); if (!s) return NULL; s->fd = fd; s->vc = qemu_new_vlan_client(vlan, net_socket_receive_dgram, s); qemu_set_fd_handler(s->fd, net_socket_send_dgram, NULL, s); /* mcast: save bound address as dst */ if (is_connected) s->dgram_dst=saddr; snprintf(s->vc->info_str, sizeof(s->vc->info_str), "socket: fd=%d (%s mcast=%s:%d)", fd, is_connected? "cloned" : "", inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port)); return s; }