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- typedef struct Opt Opt;
- int debug;
- #define DPRINT if(debug)fprint
- enum
- {
- /* control characters */
- Se= 240, /* end subnegotiation */
- NOP= 241,
- Mark= 242, /* data mark */
- Break= 243,
- Interrupt= 244,
- Abort= 245, /* TENEX ^O */
- AreYouThere= 246,
- Erasechar= 247, /* erase last character */
- Eraseline= 248, /* erase line */
- GoAhead= 249, /* half duplex clear to send */
- Sb= 250, /* start subnegotiation */
- Will= 251,
- Wont= 252,
- Do= 253,
- Dont= 254,
- Iac= 255,
- /* options */
- Binary= 0,
- Echo,
- SGA,
- Stat,
- Timing,
- Det,
- Term,
- EOR,
- Uid,
- Outmark,
- Ttyloc,
- M3270,
- Padx3,
- Window,
- Speed,
- Flow,
- Line,
- Xloc,
- Extend,
- };
- struct Opt
- {
- char *name;
- int code;
- char noway;
- int (*change)(Biobuf*, int); /* routine for status change */
- int (*sub)(Biobuf*, uchar*, int n); /* routine for subnegotiation */
- char remote; /* remote value */
- char local; /* local value */
- };
- Opt opt[] =
- {
- [Binary] { "binary", 0, 0, },
- [Echo] { "echo", 1, 0, },
- [SGA] { "suppress Go Ahead", 3, 0, },
- [Stat] { "status", 5, 1, },
- [Timing] { "timing", 6, 1, },
- [Det] { "det", 20, 1, },
- [Term] { "terminal", 24, 0, },
- [EOR] { "end of record", 25, 1, },
- [Uid] { "uid", 26, 1, },
- [Outmark] { "outmark", 27, 1, },
- [Ttyloc] { "ttyloc", 28, 1, },
- [M3270] { "3270 mode", 29, 1, },
- [Padx3] { "pad x.3", 30, 1, },
- [Window] { "window size", 31, 1, },
- [Speed] { "speed", 32, 1, },
- [Flow] { "flow control", 33, 1, },
- [Line] { "line mode", 34, 1, },
- [Xloc] { "X display loc", 35, 0, },
- [Extend] { "Extended", 255, 1, },
- };
- int control(Biobuf*, int);
- Opt* findopt(int);
- int will(Biobuf*);
- int wont(Biobuf*);
- int doit(Biobuf*);
- int dont(Biobuf*);
- int sub(Biobuf*);
- int send2(int, int, int);
- int send3(int, int, int, int);
- int sendnote(int, char*);
- void fatal(char*, void*, void*);
- char* syserr(void);
- int wasintr(void);
- long iread(int, void*, int);
- long iwrite(int, void*, int);
- void binit(Biobuf*, int);
- void berase(Biobuf*);
- void bkill(Biobuf*);
- /*
- * parse telnet control messages
- */
- int
- control(Biobuf *bp, int c)
- {
- if(c < 0)
- return -1;
- switch(c){
- case AreYouThere:
- fprint(Bfildes(bp), "Plan 9 telnet, version 1\r\n");
- break;
- case Sb:
- return sub(bp);
- case Will:
- return will(bp);
- case Wont:
- return wont(bp);
- case Do:
- return doit(bp);
- case Dont:
- return dont(bp);
- case Se:
- fprint(2, "telnet: SE without an SB\n");
- break;
- default:
- break;
- }
- return 0;
- }
- Opt*
- findopt(int c)
- {
- Opt *o;
- for(o = opt; o <= &opt[Extend]; o++)
- if(o->code == c)
- return o;
- return 0;
- }
- int
- will(Biobuf *bp)
- {
- Opt *o;
- int c;
- int rv = 0;
- c = Bgetc(bp);
- if(c < 0)
- return -1;
- DPRINT(2, "will %d\n", c);
- o = findopt(c);
- if(o == 0){
- send3(Bfildes(bp), Iac, Dont, c);
- return 0;
- }
- if(o->noway)
- send3(Bfildes(bp), Iac, Dont, c);
- else if(o->remote == 0)
- rv |= send3(Bfildes(bp), Iac, Do, c);
- if(o->remote == 0){
- if(o->change)
- rv |= (*o->change)(bp, Will);
- }
- o->remote = 1;
- return rv;
- }
- int
- wont(Biobuf *bp)
- {
- Opt *o;
- int c;
- int rv = 0;
- c = Bgetc(bp);
- if(c < 0)
- return -1;
- DPRINT(2, "wont %d\n", c);
- o = findopt(c);
- if(o == 0)
- return 0;
- if(o->remote){
- if(o->change)
- rv |= (*o->change)(bp, Wont);
- rv |= send3(Bfildes(bp), Iac, Dont, c);
- }
- o->remote = 0;
- return rv;
- }
- int
- doit(Biobuf *bp)
- {
- Opt *o;
- int c;
- int rv = 0;
- c = Bgetc(bp);
- if(c < 0)
- return -1;
- DPRINT(2, "do %d\n", c);
- o = findopt(c);
- if(o == 0 || o->noway){
- send3(Bfildes(bp), Iac, Wont, c);
- return 0;
- }
- if(o->noway)
- return 0;
- if(o->local == 0){
- if(o->change)
- rv |= (*o->change)(bp, Do);
- rv |= send3(Bfildes(bp), Iac, Will, c);
- }
- o->local = 1;
- return rv;
- }
- int
- dont(Biobuf *bp)
- {
- Opt *o;
- int c;
- int rv = 0;
- c = Bgetc(bp);
- if(c < 0)
- return -1;
- DPRINT(2, "dont %d\n", c);
- o = findopt(c);
- if(o == 0)
- return 0;
- if(o->noway)
- return 0;
- if(o->local){
- o->local = 0;
- if(o->change)
- rv |= (*o->change)(bp, Dont);
- rv |= send3(Bfildes(bp), Iac, Wont, c);
- }
- o->local = 0;
- return rv;
- }
- /* read in a subnegotiation message and pass it to a routine for that option */
- int
- sub(Biobuf *bp)
- {
- uchar subneg[128];
- uchar *p;
- Opt *o;
- int c;
- p = subneg;
- for(;;){
- c = Bgetc(bp);
- if(c == Iac){
- c = Bgetc(bp);
- if(c == Se)
- break;
- if(p < &subneg[sizeof(subneg)])
- *p++ = Iac;
- }
- if(c < 0)
- return -1;
- if(p < &subneg[sizeof(subneg)])
- *p++ = c;
- }
- if(p == subneg)
- return 0;
- DPRINT(2, "sub %d %d n = %d\n", subneg[0], subneg[1], (int)(p - subneg - 1));
- o = findopt(subneg[0]);
- if(o == 0 || o->sub == 0)
- return 0;
- return (*o->sub)(bp, subneg+1, p - subneg - 1);
- }
- void
- sendd(int c0, int c1)
- {
- char *t = 0;
- switch(c0){
- case Will:
- t = "Will";
- break;
- case Wont:
- t = "Wont";
- break;
- case Do:
- t = "Do";
- break;
- case Dont:
- t = "Dont";
- break;
- }
- if(t)
- DPRINT(2, "r %s %d\n", t, c1);
- }
- int
- send2(int f, int c0, int c1)
- {
- uchar buf[2];
- buf[0] = c0;
- buf[1] = c1;
- return iwrite(f, buf, 2) == 2 ? 0 : -1;
- }
- int
- send3(int f, int c0, int c1, int c2)
- {
- uchar buf[3];
- buf[0] = c0;
- buf[1] = c1;
- buf[2] = c2;
- sendd(c1, c2);
- return iwrite(f, buf, 3) == 3 ? 0 : -1;
- }
- int
- sendnote(int pid, char *msg)
- {
- int fd;
- char name[128];
- sprint(name, "/proc/%d/note", pid);
- fd = open(name, OWRITE);
- if(fd < 0)
- return -1;
- if(write(fd, msg, strlen(msg))!=strlen(msg))
- return -1;
- return close(fd);
- }
- void
- fatal(char *fmt, void *a0, void *a1)
- {
- char buf[128];
- sprint(buf, fmt, a0, a1);
- fprint(2, "%s: %s\n", argv0, buf);
- exits(buf);
- }
- char*
- syserr(void)
- {
- static char err[ERRMAX];
- errstr(err, sizeof err);
- return err;
- }
- int
- wasintr(void)
- {
- return strcmp(syserr(), "interrupted") == 0;
- }
- long
- iread(int f, void *a, int n)
- {
- long m;
- for(;;){
- m = read(f, a, n);
- if(m >= 0 || !wasintr())
- break;
- }
- return m;
- }
- long
- iwrite(int f, void *a, int n)
- {
- long m;
- m = write(f, a, n);
- if(m < 0 && wasintr())
- return n;
- return m;
- }
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