4 * tuntap-socket-raw create [<ifname>] => <sockid>
5 * tuntap-socket-raw ifname <sockid> => <ifname>
6 * tuntap-socket-raw close <sockid>
7 * tuntap-socket-raw receive <sockid> <data>
8 * tuntap-socket-raw on-transmit <sockid> <mtu> [<script>]
9 * calls, effectively, eval <script> [list <data> <socket>]
10 * if script not supplied, cancel
13 #include "chiark_tcl_tuntap.h"
15 typedef struct TunSocket {
16 int ix, fd, script_llength;
18 ScriptToInvoke script;
20 unsigned char *msg_buf;
24 int cht_do_tuntapsocket_create_tun(ClientData cd, Tcl_Interp *ip,
25 const char *ifname, void **sock_r) {
30 memset(&ifr,0,sizeof(ifr));
31 ifr.ifr_flags= IFF_TUN | IFF_NO_PI;
34 if (strlen(ifname) > IFNAMSIZ-1) return
35 cht_staticerr(ip,"tun interface name too long","TUNTAP IFNAME LENGTH");
36 strcpy(ifr.ifr_name, ifname);
39 fd= open("/dev/net/tun", O_RDWR);
40 if (fd<0) return cht_posixerr(ip,errno,"open /dev/net/tun");
42 r= cht_setnonblock(fd,1);
43 if (r) return cht_posixerr(ip,errno,"setnonblock tun");
45 r= ioctl(fd, TUNSETIFF, (void*)&ifr);
46 if (r) return cht_newfdposixerr(ip,fd,"ioctl TUNSETIFF");
48 sock= TALLOC(sizeof(TuntapSocket));
53 sock->ifname= TALLOC(strlen(ifr.ifr_name)+1);
54 strcpy(sock->ifname, ifr.ifr_name);
55 cht_scriptinv_init(&sock->script);
61 int cht_do_tuntapsocket_receive(ClientData cd, Tcl_Interp *ip,
62 void *sock_v, HBytes_Value data) {
63 TuntapSocket *sock= sock_v;
67 cht_hb_data(&data), l=cht_hb_len(&data));
68 if (r==-1) return cht_posixerr(ip,errno,"write tuntap");
69 else if (r!=l) return cht_staticerr(ip,"write tuntap gave wrong answer",0);
73 int cht_do_tuntapsocket_ifname(ClientData cd, Tcl_Interp *ip,
74 void *sock_v, const char **result) {
75 TuntapSocket *sock= sock_v;
76 *result= sock->ifname;
80 static void cancel(TuntapSocket *sock) {
81 if (sock->script.script) {
82 cht_scriptinv_cancel(&sock->script);
83 Tcl_DeleteFileHandler(sock->fd);
89 static void read_call(ClientData sock_cd, int mask) {
90 TuntapSocket *sock= (void*)sock_cd;
91 Tcl_Interp *ip= sock->ip;
94 HBytes_Value message_val;
98 sz= read(sock->fd, sock->msg_buf, sock->mtu);
100 if (errno == EAGAIN || errno == EWOULDBLOCK) rc=0;
101 else rc= cht_posixerr(ip,errno,"read tuntap");
105 assert(sz <= sock->mtu);
107 cht_hb_array(&message_val, sock->msg_buf, sz);
108 args[0]= cht_ret_hb(ip, message_val); cht_hb_empty(&message_val);
109 args[1]= cht_ret_iddata(ip, sock, &cht_tuntap_socks);
110 cht_scriptinv_invoke(&sock->script, 2, args);
114 if (rc) Tcl_BackgroundError(ip);
117 int cht_do_tuntapsocket_on_transmit(ClientData cd, Tcl_Interp *ip,
119 long mtu, Tcl_Obj *newscript) {
120 TuntapSocket *sock= sock_v;
124 return cht_staticerr(ip,"tuntap mtu >2^16","TUNTAP MTU OVERRUN");
129 rc= cht_scriptinv_set(&sock->script,ip,newscript,0);
133 sock->msg_buf= TALLOC(mtu);
134 Tcl_CreateFileHandler(sock->fd, TCL_READABLE, read_call, sock);
139 static void destroy(void *sock_v) {
140 TuntapSocket *sock= sock_v;
142 close(sock->fd); /* nothing useful to be done with errors */
143 TFREE(sock->msg_buf);
147 static void destroy_idtabcb(Tcl_Interp *ip, void *sock_v) {
151 int cht_do_tuntapsocket_close(ClientData cd, Tcl_Interp *ip, void *sock) {
152 cht_tabledataid_disposing(ip,sock,&cht_tuntap_socks);
157 const IdDataSpec cht_tuntap_socks= {
158 "tuntap", "tuntap-table", destroy_idtabcb
161 CHT_INIT(tuntap, { }, CHTI_COMMANDS(cht_tuntaptoplevel_entries))