ref: 6fa3e08412c49a188e2abe7d9ee54cd1f37a85f5
dir: /sys/src/cmd/ip/telnet.h/
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; }