ref: 733c5d6645b133b60d304c38fcb1398f94d0618c
dir: /sys/src/cmd/ndb/inform.c/
/* RFC2136 DNS inform - necessary for Win2k3 DNS servers */ #include <u.h> #include <libc.h> #include <bio.h> #include <ndb.h> #include <ip.h> #include "dns.h" enum { FQDNMAX = 255, }; char *errmsgs[] = { [0] "ok", [1] "request format error", [2] "internal server error", [3] "domain name does not exist", [4] "request not supported", [5] "permission denied", [6] "domain name already exists", [7] "resource record already exists", [8] "resource record does not exist", [9] "server not authoritative", [10] "domain name not in zone", }; static uchar loopbacknet[IPaddrlen] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 127, 0, 0, 0 }; static uchar loopbackmask[IPaddrlen] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0, 0 }; static uchar loopback6[IPaddrlen] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }; void usage(void) { fprint(2, "usage: %s [-x netmtpt]\n", argv0); exits("usage"); } void ding(void *, char *msg) { if(strstr(msg, "alarm") != nil) noted(NCONT); noted(NDFLT); } int g16(uchar **p) { int n; n = *(*p)++ << 8; n |= *(*p)++; return n; } void p16(uchar **p, int n) { *(*p)++ = n >> 8; *(*p)++ = n; } void p32(uchar **p, int n) { *(*p)++ = n >> 24; *(*p)++ = n >> 16; *(*p)++ = n >> 8; *(*p)++ = n; } void pmem(uchar **p, void *v, int len) { memmove(*p, v, len); *p += len; } void pname(uchar **p, char *s) { uchar *len; while (*s){ len = (*p)++; while(*s && *s != '.') *(*p)++ = *s++; *len = *p - len - 1; if(*s == '.') s++; } *(*p)++ = 0; } void main(int argc, char *argv[]) { static char *query[] = { "dom", "dnsdomain", "ns", "inform" }; char *sysname, *dnsdomain, *dom, *inform, *ns, net[32], dn[256], ds[256]; int debug, len, fd; uint err; uchar *p, buf[4096], mynet[IPaddrlen]; ushort txid; Ndb *db; Ndbtuple *t, *tt; Ipifc *ifc; Iplifc *lifc; fmtinstall('I', eipfmt); fmtinstall('V', eipfmt); setnetmtpt(net, sizeof net, nil); debug = 0; ns = nil; dom = nil; inform = nil; dnsdomain = nil; ARGBEGIN{ case 'd': debug = 1; break; case 'x': setnetmtpt(net, sizeof net, EARGF(usage())); break; default: usage(); }ARGEND; if(argc != 0) usage(); if((sysname = getenv("sysname")) == nil) sysfatal("$sysname not set"); if((db = ndbopen(nil)) == nil) sysfatal("can't open ndb: %r"); tt = ndbipinfo(db, "sys", sysname, query, nelem(query)); for(t = tt; t; t = t->entry){ if(strcmp(t->attr, "ns") == 0) ns = t->val; else if(strcmp(t->attr, "dom") == 0) dom = t->val; else if(strcmp(t->attr, "dnsdomain") == 0) dnsdomain = t->val; else if(strcmp(t->attr, "inform") == 0) inform = t->val; } ndbfree(tt); ndbclose(db); if(inform) dom = inform; if(!ns) sysfatal("no relevant ns="); if(!dom) sysfatal("no relevant dom="); if(!dnsdomain) sysfatal("no relevant dnsdomain="); if(utf2idn(dom, dn, sizeof(dn)) <= 0) sysfatal("cannot convert dom"); if(utf2idn(dnsdomain, ds, sizeof(ds)) <= 0) sysfatal("cannot convert dnsdomain"); if(debug){ print("ns=%s\n", ns); print("dnsdomain=%s\n", dnsdomain); print("dom=%s\n", dom); } if((fd = dial(netmkaddr(ns, "udp", "dns"), 0, 0, 0)) < 0) sysfatal("can't dial %s: %r", ns); txid = time(nil) + getpid(); p = buf; p16(&p, txid); /* ID */ p16(&p, 5<<11); /* flags */ p16(&p, 1); /* # Zones */ p16(&p, 0); /* # prerequisites */ p16(&p, 2); /* # updates */ p16(&p, 0); /* # additionals */ pname(&p, ds); /* zone */ p16(&p, Tsoa); /* zone type */ p16(&p, Cin); /* zone class */ /* delete old name */ pname(&p, dn); /* name */ p16(&p, Ta); /* type: v4 addr */ p16(&p, Call); /* class */ p32(&p, 0); /* TTL */ p16(&p, 0); /* data len */ pname(&p, dn); /* name */ p16(&p, Taaaa); /* type: v6 addr */ p16(&p, Call); /* class */ p32(&p, 0); /* TTL */ p16(&p, 0); /* data len */ for(ifc = readipifc(net, nil, -1); ifc != nil; ifc = ifc->next){ for(lifc = ifc->lifc; lifc != nil; lifc = lifc->next){ /* unspecified */ if(ipcmp(lifc->ip, IPnoaddr) == 0) continue; /* ipv6 loopback */ if(ipcmp(lifc->ip, loopback6) == 0) continue; /* ipv4 loopback */ maskip(lifc->ip, loopbackmask, mynet); if(ipcmp(mynet, loopbacknet) == 0) continue; if(debug) print("ip=%I\n", lifc->ip); /* add new A record */ pname(&p, dn); /* name */ p16(&p, isv4(lifc->ip)?Ta:Taaaa); p16(&p, Cin); /* class */ p32(&p, 60*60*25); /* TTL (25 hours) */ if(isv4(lifc->ip)){ p16(&p, IPv4addrlen); pmem(&p, lifc->ip+IPv4off, IPv4addrlen); } else { p16(&p, IPaddrlen); pmem(&p, lifc->ip, IPaddrlen); } } } len = p - buf; if(write(fd, buf, len) != len) sysfatal("write failed: %r"); notify(ding); alarm(3000); do{ if(read(fd, buf, sizeof buf) < 0) sysfatal("timeout"); p = buf; }while(g16(&p) != txid); alarm(0); err = g16(&p) & 7; if(err != 0 && err != 7) /* err==7 is just a "yes, I know" warning */ if(err < nelem(errmsgs)) sysfatal("%s", errmsgs[err]); else sysfatal("unknown dns server error %d", err); exits(nil); }