ref: c1d40df49550393f3afe53fb6e6d500dfa8eb7a8
dir: /sys/src/cmd/ip/pptpd.c/
#include <u.h> #include <libc.h> #include <bio.h> #include <ip.h> #define LOG "pptpd" typedef struct Call Call; typedef struct Event Event; #define SDB if(debug) fprint(2, #define EDB ); enum { Magic = 0x1a2b3c4d, Nhash = 17, Nchan = 10, /* maximum number of channels */ Window = 8, /* default window size */ Timeout = 60, /* timeout in seconds for control channel */ Pktsize = 2000, /* maximum packet size */ Tick = 500, /* tick length in milliseconds */ Sendtimeout = 4, /* in ticks */ }; enum { Syncframe = 0x1, Asyncframe = 0x2, Analog = 0x1, Digital = 0x2, Version = 0x100, }; enum { Tstart = 1, Rstart = 2, Tstop = 3, Rstop = 4, Techo = 5, Recho = 6, Tcallout = 7, Rcallout = 8, Tcallreq = 9, Rcallreq = 10, Acallcon = 11, Tcallclear = 12, Acalldis = 13, Awaninfo = 14, Alinkinfo = 15, }; struct Event { QLock; QLock waitlk; int wait; int ready; }; struct Call { int ref; QLock lk; int id; int serial; int pppfd; int closed; int pac; /* server is acting as a PAC */ int recvwindow; /* recv windows */ int sendwindow; /* send windows */ int delay; int sendaccm; int recvaccm; uint seq; /* current seq number - for send */ uint ack; /* current acked mesg - for send */ uint rseq; /* highest recv seq number for in order packet */ uint rack; /* highest ack sent */ Event eack; /* recved ack - for send */ ulong tick; uchar remoteip[IPaddrlen]; /* remote ip address */ int dhcpfd[2]; /* pipe to dhcpclient */ /* error stats */ struct { int crc; int frame; int hardware; int overrun; int timeout; int align; } err; struct { int send; int sendack; int recv; int recvack; int dropped; int missing; int sendwait; int sendtimeout; } stat; Call *next; }; struct { QLock lk; int start; int grefd; int grecfd; uchar local[IPaddrlen]; uchar remote[IPaddrlen]; char *tcpdir; uchar ipaddr[IPaddrlen]; /* starting ip addresss to allocate */ int recvwindow; char *pppdir; char *pppexec; double rcvtime; /* time at which last request was received */ int echoid; /* id of last echo request */ Call *hash[Nhash]; } srv; /* GRE flag bits */ enum { GRE_chksum = (1<<15), GRE_routing = (1<<14), GRE_key = (1<<13), GRE_seq = (1<<12), GRE_srcrt = (1<<11), GRE_recur = (7<<8), GRE_ack = (1<<7), GRE_ver = 0x7, }; /* GRE protocols */ enum { GRE_ppp = 0x880b, }; int debug; double drop; void myfatal(char *fmt, ...); #define PSHORT(p, v) ((p)[0]=((v)>>8), (p)[1]=(v)) #define PLONG(p, v) (PSHORT(p, (v)>>16), PSHORT(p+2, (v))) #define PSTRING(d,s,n) strncpy((char*)(d), s, n) #define GSHORT(p) (((p)[0]<<8) | ((p)[1]<<0)) #define GLONG(p) ((GSHORT((p))<<16) | ((GSHORT((p)+2))<<0)) #define GSTRING(d,s,n) strncpy(d, (char*)(s), n), d[(n)-1] = 0 void serve(void); int sstart(uchar*, int); int sstop(uchar*, int); int secho(uchar*, int); int scallout(uchar*, int); int scallreq(uchar*, int); int scallcon(uchar*, int); int scallclear(uchar*, int); int scalldis(uchar*, int); int swaninfo(uchar*, int); int slinkinfo(uchar*, int); Call *callalloc(int id); void callclose(Call*); void callfree(Call*); Call *calllookup(int id); void gretimeout(void*); void pppread(void*); void srvinit(void); void greinit(void); void greread(void*); void greack(Call *c); void timeoutthread(void*); int argatoi(char *p); void usage(void); int ipaddralloc(Call *c); void *emallocz(int size); void esignal(Event *e); void ewait(Event *e); int proc(char **argv, int fd0, int fd1, int fd2); double realtime(void); ulong thread(void(*f)(void*), void *a); void main(int argc, char *argv[]) { ARGBEGIN{ case 'd': debug++; break; case 'p': srv.pppdir = ARGF(); break; case 'P': srv.pppexec = ARGF(); break; case 'w': srv.recvwindow = argatoi(ARGF()); break; case 'D': drop = atof(ARGF()); break; default: usage(); }ARGEND fmtinstall('I', eipfmt); fmtinstall('E', eipfmt); fmtinstall('V', eipfmt); fmtinstall('M', eipfmt); rfork(RFNOTEG|RFREND); if(argc != 1) usage(); srv.tcpdir = argv[0]; srvinit(); syslog(0, LOG, ": src=%I: pptp started: %d", srv.remote, getpid()); SDB "\n\n\n%I: pptp started\n", srv.remote EDB greinit(); thread(timeoutthread, 0); serve(); syslog(0, LOG, ": src=%I: server exits", srv.remote); postnote(PNGROUP, getpid(), "die"); exits(0); } void usage(void) { fprint(2, "usage: pptpd [-dD] [-p ppp-net] [-w window] tcpdir\n"); exits("usage"); } void serve(void) { uchar buf[2000], *p; int n, n2, len; int magic; int op, type; n = 0; for(;;) { n2 = read(0, buf+n, sizeof(buf)-n); if(n2 < 0) myfatal("bad read on ctl channel: %r"); if(n2 == 0) break; n += n2; p = buf; for(;;) { if(n < 12) break; qlock(&srv.lk); srv.rcvtime = realtime(); qunlock(&srv.lk); len = GSHORT(p); type = GSHORT(p+2); magic = GLONG(p+4); op = GSHORT(p+8); if(magic != Magic) myfatal("bad magic number: got %x", magic); if(type != 1) myfatal("bad message type: %d", type); switch(op) { default: myfatal("unknown control op: %d", op); case Tstart: /* start-control-connection-request */ n2 = sstart(p, n); break; case Tstop: n2 = sstop(p, n); if(n2 > 0) return; break; case Techo: n2 = secho(p, n); break; case Tcallout: n2 = scallout(p, n); break; case Tcallreq: n2 = scallreq(p, n); break; case Acallcon: n2 = scallcon(p, n); break; case Tcallclear: n2 = scallclear(p, n); break; case Acalldis: n2 = scalldis(p, n); break; case Awaninfo: n2 = swaninfo(p, n); break; case Alinkinfo: n2 = slinkinfo(p, n); break; } if(n2 == 0) break; if(n2 != len) myfatal("op=%d: bad length: got %d expected %d", op, len, n2); n -= n2; p += n2; } /* move down partial message */ if(p != buf && n != 0) memmove(buf, p, n); } } int sstart(uchar *p, int n) { int ver, frame, bearer, maxchan, firm; char host[64], vendor[64], *sysname; uchar buf[156]; if(n < 156) return 0; ver = GSHORT(p+12); frame = GLONG(p+16); bearer = GLONG(p+20); maxchan = GSHORT(p+24); firm = GSHORT(p+26); GSTRING(host, p+28, 64); GSTRING(vendor, p+92, 64); SDB "%I: start ver = %x f = %d b = %d maxchan = %d firm = %d host = %s vendor = %s\n", srv.remote, ver, frame, bearer, maxchan, firm, host, vendor EDB if(ver != Version) myfatal("bad version: got %x expected %x", ver, Version); if(srv.start) myfatal("multiple start messages"); srv.start = 1; sysname = getenv("sysname"); if(sysname == 0) strcpy(host, "gnot"); else strncpy(host, sysname, 64); free(sysname); memset(buf, 0, sizeof(buf)); PSHORT(buf+0, sizeof(buf)); /* length */ PSHORT(buf+2, 1); /* message type */ PLONG(buf+4, Magic); /* magic */ PSHORT(buf+8, Rstart); /* op */ PSHORT(buf+12, Version); /* version */ buf[14] = 1; /* result = ok */ PLONG(buf+16, Syncframe|Asyncframe); /* frameing */ PLONG(buf+20, Digital|Analog); /* berear capabilities */ PSHORT(buf+24, Nchan); /* max channels */ PSHORT(buf+26, 1); /* driver version */ PSTRING(buf+28, host, 64); /* host name */ PSTRING(buf+92, "plan 9", 64); /* vendor */ if(write(1, buf, sizeof(buf)) < sizeof(buf)) myfatal("write failed: %r"); return 156; } int sstop(uchar *p, int n) { int reason; uchar buf[16]; if(n < 16) return 0; reason = p[12]; SDB "%I: stop %d\n", srv.remote, reason EDB memset(buf, 0, sizeof(buf)); PSHORT(buf+0, sizeof(buf)); /* length */ PSHORT(buf+2, 1); /* message type */ PLONG(buf+4, Magic); /* magic */ PSHORT(buf+8, Rstop); /* op */ buf[12] = 1; /* ok */ if(write(1, buf, sizeof(buf)) < sizeof(buf)) myfatal("write failed: %r"); return 16; } int secho(uchar *p, int n) { int id; uchar buf[20]; if(n < 16) return 0; id = GLONG(p+12); SDB "%I: echo %d\n", srv.remote, id EDB memset(buf, 0, sizeof(buf)); PSHORT(buf+0, sizeof(buf)); /* length */ PSHORT(buf+2, 1); /* message type */ PLONG(buf+4, Magic); /* magic */ PSHORT(buf+8, Recho); /* op */ PLONG(buf+12, id); /* id */ p[16] = 1; /* ok */ if(write(1, buf, sizeof(buf)) < sizeof(buf)) myfatal("write failed: %r"); return 16; } int scallout(uchar *p, int n) { int id, serial; int minbps, maxbps, bearer, frame; int window, delay; int nphone; char phone[64], sub[64], buf[32]; Call *c; if(n < 168) return 0; if(!srv.start) myfatal("%I: did not recieve start message", srv.remote); id = GSHORT(p+12); serial = GSHORT(p+14); minbps = GLONG(p+16); maxbps = GLONG(p+20); bearer = GLONG(p+24); frame = GLONG(p+28); window = GSHORT(p+32); delay = GSHORT(p+34); nphone = GSHORT(p+36); GSTRING(phone, p+40, 64); GSTRING(sub, p+104, 64); SDB "%I: callout id = %d serial = %d bps=[%d,%d] b=%x f=%x win = %d delay = %d np=%d phone=%s sub=%s\n", srv.remote, id, serial, minbps, maxbps, bearer, frame, window, delay, nphone, phone, sub EDB c = callalloc(id); c->sendwindow = window; c->delay = delay; c->pac = 1; c->recvwindow = srv.recvwindow; memset(buf, 0, sizeof(buf)); PSHORT(buf+0, sizeof(buf)); /* length */ PSHORT(buf+2, 1); /* message type */ PLONG(buf+4, Magic); /* magic */ PSHORT(buf+8, Rcallout); /* op */ PSHORT(buf+12, id); /* call id */ PSHORT(buf+14, id); /* peer id */ buf[16] = 1; /* ok */ PLONG(buf+20, 10000000); /* speed */ PSHORT(buf+24, c->recvwindow); /* window size */ PSHORT(buf+26, 0); /* delay */ PLONG(buf+28, 0); /* channel id */ if(write(1, buf, sizeof(buf)) < sizeof(buf)) myfatal("write failed: %r"); return 168; } int scallreq(uchar *p, int n) { USED(p); USED(n); myfatal("callreq: not done yet"); return 0; } int scallcon(uchar *p, int n) { USED(p); USED(n); myfatal("callcon: not done yet"); return 0; } int scallclear(uchar *p, int n) { Call *c; int id; uchar buf[148]; if(n < 16) return 0; id = GSHORT(p+12); SDB "%I: callclear id=%d\n", srv.remote, id EDB if(c = calllookup(id)) { callclose(c); callfree(c); } memset(buf, 0, sizeof(buf)); PSHORT(buf+0, sizeof(buf)); /* length */ PSHORT(buf+2, 1); /* message type */ PLONG(buf+4, Magic); /* magic */ PSHORT(buf+8, Acalldis); /* op */ PSHORT(buf+12, id); /* id */ buf[14] = 3; /* reply to callclear */ if(write(1, buf, sizeof(buf)) < sizeof(buf)) myfatal("write failed: %r"); return 16; } int scalldis(uchar *p, int n) { Call *c; int id, res; if(n < 148) return 0; id = GSHORT(p+12); res = p[14]; SDB "%I: calldis id=%d res=%d\n", srv.remote, id, res EDB if(c = calllookup(id)) { callclose(c); callfree(c); } return 148; } int swaninfo(uchar *p, int n) { Call *c; int id; if(n < 40) return 0; id = GSHORT(p+12); SDB "%I: waninfo id = %d\n", srv.remote, id EDB c = calllookup(id); if(c != 0) { c->err.crc = GLONG(p+16); c->err.frame = GLONG(p+20); c->err.hardware = GLONG(p+24); c->err.overrun = GLONG(p+28); c->err.timeout = GLONG(p+32); c->err.align = GLONG(p+36); callfree(c); } return 40; } int slinkinfo(uchar *p, int n) { Call *c; int id; int sendaccm, recvaccm; if(n < 24) return 0; id = GSHORT(p+12); sendaccm = GLONG(p+16); recvaccm = GLONG(p+20); SDB "%I: linkinfo id=%d saccm=%ux raccm=%ux\n", srv.remote, id, sendaccm, recvaccm EDB if(c = calllookup(id)) { c->sendaccm = sendaccm; c->recvaccm = recvaccm; callfree(c); } return 24; } Call* callalloc(int id) { uint h; Call *c; char *argv[30], local[20], remote[20], **p; int pfd[2]; h = id%Nhash; qlock(&srv.lk); for(c=srv.hash[h]; c; c=c->next) if(c->id == id) myfatal("callalloc: duplicate id: %d", id); c = emallocz(sizeof(Call)); c->ref = 1; c->id = id; c->sendaccm = ~0; c->recvaccm = ~0; if(!ipaddralloc(c)) myfatal("callalloc: could not alloc remote ip address"); if(pipe(pfd) < 0) myfatal("callalloc: pipe failed: %r"); p = argv; *p++ = srv.pppexec; *p++ = "-SC"; *p++ = "-x"; *p++ = srv.pppdir; if(debug) *p++ = "-d"; sprint(local, "%I", srv.ipaddr); *p++ = local; sprint(remote, "%I", c->remoteip); *p++ = remote; *p = 0; proc(argv, pfd[0], pfd[0], 2); close(pfd[0]); c->pppfd = pfd[1]; c->next = srv.hash[h]; srv.hash[h] = c; qunlock(&srv.lk); c->ref++; thread(pppread, c); c->ref++; thread(gretimeout, c); syslog(0, LOG, ": src=%I: call started: id=%d: remote ip=%I", srv.remote, id, c->remoteip); return c; } void callclose(Call *c) { Call *oc; int id; uint h; syslog(0, LOG, ": src=%I: call closed: id=%d: send=%d sendack=%d recv=%d recvack=%d dropped=%d missing=%d sendwait=%d sendtimeout=%d", srv.remote, c->id, c->stat.send, c->stat.sendack, c->stat.recv, c->stat.recvack, c->stat.dropped, c->stat.missing, c->stat.sendwait, c->stat.sendtimeout); qlock(&srv.lk); if(c->closed) { qunlock(&srv.lk); return; } c->closed = 1; close(c->dhcpfd[0]); close(c->dhcpfd[1]); close(c->pppfd); c->pppfd = -1; h = c->id%Nhash; id = c->id; for(c=srv.hash[h],oc=0; c; oc=c,c=c->next) if(c->id == id) break; if(oc == 0) srv.hash[h] = c->next; else oc->next = c->next; c->next = 0; qunlock(&srv.lk); callfree(c); } void callfree(Call *c) { int ref; qlock(&srv.lk); ref = --c->ref; qunlock(&srv.lk); if(ref > 0) return; /* already unhooked from hash list - see callclose */ assert(c->closed == 1); assert(ref == 0); assert(c->next == 0); SDB "call free\n" EDB free(c); } Call* calllookup(int id) { uint h; Call *c; h = id%Nhash; qlock(&srv.lk); for(c=srv.hash[h]; c; c=c->next) if(c->id == id) break; if(c != 0) c->ref++; qunlock(&srv.lk); return c; } void srvinit(void) { char buf[100]; int fd, n; sprint(buf, "%s/local", srv.tcpdir); if((fd = open(buf, OREAD)) < 0) myfatal("could not open %s: %r", buf); if((n = read(fd, buf, sizeof(buf))) < 0) myfatal("could not read %s: %r", buf); buf[n] = 0; parseip(srv.local, buf); close(fd); sprint(buf, "%s/remote", srv.tcpdir); if((fd = open(buf, OREAD)) < 0) myfatal("could not open %s: %r", buf); if((n = read(fd, buf, sizeof(buf))) < 0) myfatal("could not read %s: %r", buf); buf[n] = 0; parseip(srv.remote, buf); close(fd); if(srv.pppdir == 0) srv.pppdir = "/net"; if(srv.pppexec == 0) srv.pppexec = "/bin/ip/ppp"; if(myipaddr(srv.ipaddr, srv.pppdir) < 0) myfatal("could not read local ip addr: %r"); if(srv.recvwindow == 0) srv.recvwindow = Window; } void greinit(void) { char addr[100], *p; int fd, cfd; SDB "srv.tcpdir = %s\n", srv.tcpdir EDB strcpy(addr, srv.tcpdir); p = strrchr(addr, '/'); if(p == 0) myfatal("bad tcp dir: %s", srv.tcpdir); *p = 0; p = strrchr(addr, '/'); if(p == 0) myfatal("bad tcp dir: %s", srv.tcpdir); sprint(p, "/gre!%I!34827", srv.remote); SDB "addr = %s\n", addr EDB fd = dial(addr, 0, 0, &cfd); if(fd < 0) myfatal("%I: dial %s failed: %r", srv.remote, addr); srv.grefd = fd; srv.grecfd = cfd; thread(greread, 0); } void greread(void *) { uchar buf[Pktsize], *p; int n, i; int flag, prot, len, callid; uchar src[IPaddrlen], dst[IPaddrlen]; uint rseq, ack; Call *c; static double t, last; for(;;) { n = read(srv.grefd, buf, sizeof(buf)); if(n < 0) myfatal("%I: bad read on gre: %r", srv.remote); if(n == sizeof(buf)) myfatal("%I: gre read: buf too small", srv.remote); p = buf; v4tov6(src, p); v4tov6(dst, p+4); flag = GSHORT(p+8); prot = GSHORT(p+10); p += 12; n -= 12; if(ipcmp(src, srv.remote) != 0 || ipcmp(dst, srv.local) != 0) myfatal("%I: gre read bad address src=%I dst=%I", srv.remote, src, dst); if(prot != GRE_ppp) myfatal("%I: gre read gave bad protocol", srv.remote); if(flag & (GRE_chksum|GRE_routing)){ p += 4; n -= 4; } if(!(flag&GRE_key)) myfatal("%I: gre packet does not contain a key: f=%ux", srv.remote, flag); len = GSHORT(p); callid = GSHORT(p+2); p += 4; n -= 4; c = calllookup(callid); if(c == 0) { SDB "%I: unknown callid: %d\n", srv.remote, callid EDB continue; } qlock(&c->lk); c->stat.recv++; if(flag&GRE_seq) { rseq = GLONG(p); p += 4; n -= 4; } else rseq = c->rseq; if(flag&GRE_ack){ ack = GLONG(p); p += 4; n -= 4; } else ack = c->ack; /* skip routing if present */ if(flag&GRE_routing) { while((i=p[3]) != 0) { n -= i; p += i; } } if(len > n) myfatal("%I: bad len in gre packet", srv.remote); if((int)(ack-c->ack) > 0) { c->ack = ack; esignal(&c->eack); } if(debug) t = realtime(); if(len == 0) { /* ack packet */ c->stat.recvack++; SDB "%I: %.3f (%.3f): gre %d: recv ack a=%ux n=%d flag=%ux\n", srv.remote, t, t-last, c->id, ack, n, flag EDB } else { SDB "%I: %.3f (%.3f): gre %d: recv s=%ux a=%ux len=%d\n", srv.remote, t, t-last, c->id, rseq, ack, len EDB /* * the following handles the case of a single pair of packets * received out of order */ n = rseq-c->rseq; if(n > 0 && (drop == 0. || frand() > drop)) { c->stat.missing += n-1; /* current packet */ write(c->pppfd, p, len); } else { /* out of sequence - drop on the floor */ c->stat.dropped++; SDB "%I: %.3f: gre %d: recv out of order or dup packet: seq=%ux len=%d\n", srv.remote, realtime(), c->id, rseq, len EDB } } if((int)(rseq-c->rseq) > 0) c->rseq = rseq; if(debug) last=t; /* open up client window */ if((int)(c->rseq-c->rack) > (c->recvwindow>>1)) greack(c); qunlock(&c->lk); callfree(c); } } void greack(Call *c) { uchar buf[20]; c->stat.sendack++; SDB "%I: %.3f: gre %d: send ack %ux\n", srv.remote, realtime(), c->id, c->rseq EDB v6tov4(buf+0, srv.local); /* source */ v6tov4(buf+4, srv.remote); /* source */ PSHORT(buf+8, GRE_key|GRE_ack|1); PSHORT(buf+10, GRE_ppp); PSHORT(buf+12, 0); PSHORT(buf+14, c->id); PLONG(buf+16, c->rseq); write(srv.grefd, buf, sizeof(buf)); c->rack = c->rseq; } void gretimeout(void *a) { Call *c; c = a; while(!c->closed) { sleep(Tick); qlock(&c->lk); c->tick++; qunlock(&c->lk); esignal(&c->eack); } callfree(c); exits(0); } void pppread(void *a) { Call *c; uchar buf[2000], *p; int n; ulong tick; c = a; for(;;) { p = buf+24; n = read(c->pppfd, p, sizeof(buf)-24); if(n <= 0) break; qlock(&c->lk); /* add gre header */ c->seq++; tick = c->tick; while(c->seq-c->ack>c->sendwindow && c->tick-tick<Sendtimeout && !c->closed) { c->stat.sendwait++; SDB "window full seq = %d ack = %ux window = %ux\n", c->seq, c->ack, c->sendwindow EDB qunlock(&c->lk); ewait(&c->eack); qlock(&c->lk); } if(c->tick-tick >= Sendtimeout) { c->stat.sendtimeout++; SDB "send timeout = %d ack = %ux window = %ux\n", c->seq, c->ack, c->sendwindow EDB } v6tov4(buf+0, srv.local); /* source */ v6tov4(buf+4, srv.remote); /* source */ PSHORT(buf+8, GRE_key|GRE_seq|GRE_ack|1); PSHORT(buf+10, GRE_ppp); PSHORT(buf+12, n); PSHORT(buf+14, c->id); PLONG(buf+16, c->seq); PLONG(buf+20, c->rseq); c->stat.send++; c->rack = c->rseq; SDB "%I: %.3f: gre %d: send s=%ux a=%ux len=%d\n", srv.remote, realtime(), c->id, c->seq, c->rseq, n EDB if(drop == 0. || frand() > drop) if(write(srv.grefd, buf, n+24)<n+24) myfatal("pppread: write failed: %r"); qunlock(&c->lk); } SDB "pppread exit: %d\n", c->id); callfree(c); exits(0); } void timeoutthread(void*) { for(;;) { sleep(30*1000); qlock(&srv.lk); if(realtime() - srv.rcvtime > 5*60) myfatal("server timedout"); qunlock(&srv.lk); } } /* use syslog() rather than fprint(2, ...) */ void myfatal(char *fmt, ...) { char sbuf[512]; va_list arg; uchar buf[16]; /* NT don't seem to like us just going away */ memset(buf, 0, sizeof(buf)); PSHORT(buf+0, sizeof(buf)); /* length */ PSHORT(buf+2, 1); /* message type */ PLONG(buf+4, Magic); /* magic */ PSHORT(buf+8, Tstop); /* op */ buf[12] = 3; /* local shutdown */ write(1, buf, sizeof(buf)); va_start(arg, fmt); vseprint(sbuf, sbuf+sizeof(sbuf), fmt, arg); va_end(arg); SDB "%I: fatal: %s\n", srv.remote, sbuf EDB syslog(0, LOG, ": src=%I: fatal: %s", srv.remote, sbuf); close(0); close(1); close(srv.grefd); close(srv.grecfd); postnote(PNGROUP, getpid(), "die"); exits(sbuf); } int argatoi(char *p) { char *q; int i; if(p == 0) usage(); i = strtol(p, &q, 0); if(q == p) usage(); return i; } void dhcpclientwatch(void *a) { Call *c = a; uchar buf[1]; for(;;) { if(read(c->dhcpfd[0], buf, sizeof(buf)) <= 0) break; } if(!c->closed) myfatal("dhcpclient terminated"); callfree(c); exits(0); } int ipaddralloc(Call *c) { int pfd[2][2]; char *argv[4], *p; Biobuf bio; argv[0] = "/bin/ip/dhcpclient"; argv[1] = "-x"; argv[2] = srv.pppdir; argv[3] = 0; if(pipe(pfd[0])<0) myfatal("ipaddralloc: pipe failed: %r"); if(pipe(pfd[1])<0) myfatal("ipaddralloc: pipe failed: %r"); if(proc(argv, pfd[0][0], pfd[1][1], 2) < 0) myfatal("ipaddralloc: proc failed: %r"); close(pfd[0][0]); close(pfd[1][1]); c->dhcpfd[0] = pfd[1][0]; c->dhcpfd[1] = pfd[0][1]; Binit(&bio, pfd[1][0], OREAD); for(;;) { p = Brdline(&bio, '\n'); if(p == 0) break; if(strncmp(p, "ip=", 3) == 0) { p += 3; parseip(c->remoteip, p); } else if(strncmp(p, "end\n", 4) == 0) break; } Bterm(&bio); c->ref++; thread(dhcpclientwatch, c); return ipcmp(c->remoteip, IPnoaddr) != 0; } void esignal(Event *e) { qlock(e); if(e->wait == 0) { e->ready = 1; qunlock(e); return; } assert(e->ready == 0); e->wait = 0; rendezvous(e, (void*)1); qunlock(e); } void ewait(Event *e) { qlock(&e->waitlk); qlock(e); assert(e->wait == 0); if(e->ready) { e->ready = 0; } else { e->wait = 1; qunlock(e); rendezvous(e, (void*)2); qlock(e); } qunlock(e); qunlock(&e->waitlk); } ulong thread(void(*f)(void*), void *a) { int pid; pid=rfork(RFNOWAIT|RFMEM|RFPROC); if(pid < 0) myfatal("rfork failed: %r"); if(pid != 0) return pid; (*f)(a); return 0; // never reaches here } double realtime(void) { long times(long*); return times(0) / 1000.0; } void * emallocz(int size) { void *p; p = malloc(size); if(p == 0) myfatal("malloc failed: %r"); memset(p, 0, size); return p; } static void fdclose(void) { int fd, n, i; Dir *d, *p; if((fd = open("/fd", OREAD)) < 0) return; n = dirreadall(fd, &d); for(p = d; n > 0; n--, p++) { i = atoi(p->name); if(i > 2) close(i); } free(d); } int proc(char **argv, int fd0, int fd1, int fd2) { int r, flag; char *arg0, file[200]; arg0 = argv[0]; strcpy(file, arg0); if(access(file, 1) < 0) { if(strncmp(arg0, "/", 1)==0 || strncmp(arg0, "#", 1)==0 || strncmp(arg0, "./", 2)==0 || strncmp(arg0, "../", 3)==0) return 0; sprint(file, "/bin/%s", arg0); if(access(file, 1) < 0) return 0; } flag = RFPROC|RFFDG|RFENVG|RFNOWAIT; if((r = rfork(flag)) != 0) { if(r < 0) return 0; return r; } if(fd0 != 0) { if(fd1 == 0) fd1 = dup(0, -1); if(fd2 == 0) fd2 = dup(0, -1); close(0); if(fd0 >= 0) dup(fd0, 0); } if(fd1 != 1) { if(fd2 == 1) fd2 = dup(1, -1); close(1); if(fd1 >= 0) dup(fd1, 1); } if(fd2 != 2) { close(2); if(fd2 >= 0) dup(fd2, 2); } fdclose(); exec(file, argv); myfatal("proc: exec failed: %r"); return 0; }