ref: a3f3e31b204821b31891c91dbb4266a03c82bf0b
parent: eed90aa0ad7ac012d9f1abe638074156654d81ef
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Sun Jun 10 18:08:57 EDT 2018
dhcp6d: add minimal stateless DHCPv6 server for network boot and DNS configuration
--- a/sys/man/8/dhcpd
+++ b/sys/man/8/dhcpd
@@ -1,6 +1,6 @@
.TH DHCPD 8
.SH NAME
-dhcpd, dhcpleases, rarpd, tftpd \- Internet booting
+dhcpd, dhcp6d, dhcpleases, rarpd, tftpd \- Internet booting
.SH SYNOPSIS
.PP
.B ip/dhcpd
@@ -20,6 +20,13 @@
.PP
.B ip/dhcpleases
.PP
+.B ip/dhcp6d
+.RB [ -d ]
+.RB [ -f
+.IR ndb-file ]
+.RB [ -x
+.IR netmtpt ]
+.PP
.B ip/rarpd
.RB [ -d ]
.RB [ -e
@@ -37,7 +44,8 @@
These programs support booting over the Internet.
They should all be run on the same server to
allow other systems to be booted.
-.I Dhcpd
+.IR Dhcpd ,
+.I dhcp6d
and
.I tftpd
are used to boot everything;
@@ -220,6 +228,10 @@
.I secs
as the minimum lease time for static addresses.
.PD
+.PP
+.I Dhcp6d
+provides DHCPv6 service for IPv6 clients. Only network boot and
+DNS parameters are supported.
.PP
.I Dhcpleases
prints out the currently valid DHCP leases found in the
--- /dev/null
+++ b/sys/src/cmd/ip/dhcp6d.c
@@ -1,0 +1,561 @@
+/* minimal stateless DHCPv6 server for network boot */
+#include <u.h>
+#include <libc.h>
+#include <ip.h>
+#include <bio.h>
+#include <ndb.h>
+
+enum {+ Eaddrlen = 6,
+};
+
+typedef struct Req Req;
+struct Req
+{+ int tra;
+
+ Udphdr *udp;
+ Ipifc *ifc;
+
+ uchar mac[Eaddrlen];
+ uchar ips[IPaddrlen*8];
+ int nips;
+
+ Ndb *db;
+ Ndbtuple *t;
+
+ struct {+ int t;
+ uchar *p;
+ uchar *e;
+ } req;
+
+ struct {+ int t;
+ uchar *p;
+ uchar *e;
+ } resp;
+};
+
+typedef struct Otab Otab;
+struct Otab
+{+ int t;
+ int (*f)(uchar *, int, Otab*, Req*);
+ char *q[3];
+ int done;
+};
+
+static Otab otab[];
+static Ipifc *ipifcs;
+static ulong starttime;
+static int debug;
+
+static uchar v6loopback[IPaddrlen] = {+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 1
+};
+
+/*
+ * open ndbfile as db if not already open. also check for stale data
+ * and reload as needed.
+ */
+static Ndb *
+opendb(char *ndbfile)
+{+ static Ndb *db;
+ /* check no more often than once every minute */
+ if(db == nil)
+ db = ndbopen(ndbfile);
+ else if (ndbchanged(db))
+ ndbreopen(db);
+ return db;
+}
+
+static Ipifc*
+findifc(char *net, uchar ip[IPaddrlen])
+{+ Ipifc *ifc;
+ Iplifc *lifc;
+
+ ipifcs = readipifc(net, ipifcs, -1);
+ for(ifc = ipifcs; ifc != nil; ifc = ifc->next)
+ for(lifc = ifc->lifc; lifc != nil; lifc = lifc->next)
+ if(ipcmp(lifc->ip, ip) == 0)
+ return ifc;
+
+ return nil;
+}
+
+static int
+openlisten(char *net)
+{+ int fd, cfd;
+ char data[128], devdir[40];
+ Ipifc *ifc;
+
+ sprint(data, "%s/udp!*!dhcp6s", net);
+ cfd = announce(data, devdir);
+ if(cfd < 0)
+ sysfatal("can't announce: %r");+ if(fprint(cfd, "headers") < 0)
+ sysfatal("can't set header mode: %r");+
+ ipifcs = readipifc(net, ipifcs, -1);
+ for(ifc = ipifcs; ifc != nil; ifc = ifc->next){+ if(ifc->lifc == nil)
+ continue;
+ if(strcmp(ifc->dev, "/dev/null") == 0)
+ continue;
+ if(fprint(cfd, "addmulti %I ff02::1:2", ifc->lifc->ip) < 0)
+ fprint(2, "can't add interface %s: %r", ifc->dev);
+ }
+
+ sprint(data, "%s/data", devdir);
+ fd = open(data, ORDWR);
+ if(fd < 0)
+ sysfatal("open udp data: %r");+
+ return fd;
+}
+
+static uchar*
+gettlv(int x, int *plen, uchar *p, uchar *e)
+{+ int t;
+ int l;
+
+ if(plen != nil)
+ *plen = 0;
+ while(p+4 <= e){+ t = p[0]<<8 | p[1];
+ l = p[2]<<8 | p[3];
+ if(p+4+l > e)
+ break;
+ if(t == x){+ if(plen != nil)
+ *plen = l;
+ return p+4;
+ }
+ p += l+4;
+ }
+ return nil;
+}
+
+static int
+getv6ips(uchar *ip, int n, Ndbtuple *t, char *attr)
+{+ int r = 0;
+
+ if(n < IPaddrlen)
+ return 0;
+ if(*attr == '@')
+ attr++;
+ for(; t != nil; t = t->entry){+ if(strcmp(t->attr, attr) != 0)
+ continue;
+ if(parseip(ip, t->val) == -1)
+ continue;
+ if(isv4(ip))
+ continue;
+ ip += IPaddrlen;
+ r += IPaddrlen;
+ if(r >= n)
+ break;
+ }
+ return r;
+}
+
+static int
+lookupips(uchar *ip, int n, Ndb *db, uchar mac[Eaddrlen])
+{+ Ndbtuple *t;
+ Ndbs s;
+ char val[256], *attr;
+ int r;
+
+ /*
+ * use hardware address to find an ip address
+ */
+ attr = "ether";
+ snprint(val, sizeof val, "%E", mac);
+
+ t = ndbsearch(db, &s, attr, val);
+ r = 0;
+ while(t != nil){+ r += getv6ips(ip + r, n - r, t, "ip");
+ ndbfree(t);
+ if(r >= n)
+ break;
+ t = ndbsnext(&s, attr, val);
+ }
+ return r;
+}
+
+static void
+clearotab(void)
+{+ Otab *o;
+
+ for(o = otab; o->t != 0; o++)
+ o->done = 0;
+}
+
+static Otab*
+findotab(int t)
+{+ Otab *o;
+
+ for(o = otab; o->t != 0; o++)
+ if(o->t == t)
+ return o;
+ return nil;
+}
+
+static int
+addoption(Req *r, int t)
+{+ Otab *o;
+ int n;
+
+ if(r->resp.p+4 > r->resp.e)
+ return -1;
+ o = findotab(t);
+ if(o == nil || o->f == nil || o->done)
+ return -1;
+ o->done = 1;
+ n = (*o->f)(r->resp.p+4, r->resp.e - (r->resp.p+4), o, r);
+ if(n < 0 || r->resp.p+4+n > r->resp.e)
+ return -1;
+ r->resp.p[0] = t>>8, r->resp.p[1] = t;
+ r->resp.p[2] = n>>8, r->resp.p[3] = n;
+ if(debug) fprint(2, "%d(%.*H)\n", t, n, r->resp.p+4);
+ r->resp.p += 4+n;
+ return n;
+}
+
+static void
+usage(void)
+{+ fprint(2, "%s [-d] [-f ndbfile] [-x netmtpt]\n", argv0);
+ exits("usage");+}
+
+void
+main(int argc, char *argv[])
+{+ char *ndbfile = nil;
+ char *net = "/net";
+ uchar ibuf[4096], obuf[4096];
+ Req r[1];
+ int fd, n, i;
+
+ fmtinstall('H', encodefmt);+ fmtinstall('I', eipfmt);+ fmtinstall('E', eipfmt);+
+ ARGBEGIN {+ case 'd':
+ debug++;
+ break;
+ case 'f':
+ ndbfile = EARGF(usage());
+ break;
+ case 'x':
+ net = EARGF(usage());
+ break;
+ default:
+ usage();
+ } ARGEND;
+
+ starttime = time(nil) - 946681200UL;
+
+ if(opendb(ndbfile) == nil)
+ sysfatal("opendb: %r");+
+ fd = openlisten(net);
+
+ /* put process in background */
+ if(!debug)
+ switch(rfork(RFNOTEG|RFPROC|RFFDG)) {+ default:
+ exits(nil);
+ case -1:
+ sysfatal("fork: %r");+ case 0:
+ break;
+ }
+
+ while((n = read(fd, ibuf, sizeof(ibuf))) > Udphdrsize+4){+ r->req.p = ibuf+Udphdrsize;
+ r->req.e = ibuf+n;
+
+ memmove(obuf, ibuf, Udphdrsize);
+ r->udp = (Udphdr*)obuf;
+ r->resp.p = obuf+Udphdrsize;
+ r->resp.e = &obuf[sizeof(obuf)];
+
+ r->tra = r->req.p[1]<<16 | r->req.p[2]<<8 | r->req.p[3];
+ r->req.t = r->req.p[0];
+
+ if((r->ifc = findifc(net, r->udp->ifcaddr)) == nil)
+ continue;
+
+ if(debug)
+ fprint(2, "%I->%I(%s) typ=%d tra=%x\n",
+ r->udp->raddr, r->udp->laddr, r->ifc->dev,
+ r->req.t, r->tra);
+
+ switch(r->req.t){+ default:
+ continue;
+ case 1: /* solicit */
+ r->resp.t = 2; /* advertise */
+ break;
+ case 3: /* request */
+ case 11: /* information request */
+ r->resp.t = 7; /* reply */
+ break;
+ }
+ r->resp.p[0] = r->resp.t;
+ r->resp.p[1] = r->tra>>16;
+ r->resp.p[2] = r->tra>>8;
+ r->resp.p[3] = r->tra;
+
+ r->req.p += 4;
+ r->resp.p += 4;
+
+ r->t = nil;
+
+ clearotab();
+
+ /* Server Identifier */
+ if(addoption(r, 2) < 0)
+ continue;
+
+ /* Client Identifier */
+ if(addoption(r, 1) < 0)
+ continue;
+
+ /* Lookup taret ip addresses */
+ if((r->db = opendb(ndbfile)) == nil)
+ continue;
+ r->nips = lookupips(r->ips, sizeof(r->ips), r->db, r->mac)/IPaddrlen;
+ if(debug){+ for(i=0; i<r->nips; i++)
+ fprint(2, "ip=%I\n", r->ips+i*IPaddrlen);
+ }
+
+ addoption(r, 3);
+ addoption(r, 6);
+
+ write(fd, obuf, r->resp.p-obuf);
+ if(debug) fprint(2, "\n");
+ }
+
+ exits(nil);
+}
+
+static int
+oclientid(uchar *w, int n, Otab*, Req *r)
+{+ int len;
+ uchar *p;
+
+ if((p = gettlv(1, &len, r->req.p, r->req.e)) == nil)
+ return -1;
+ if(len < 4+4+Eaddrlen || n < len)
+ return -1;
+ memmove(r->mac, p+len-Eaddrlen, Eaddrlen);
+ memmove(w, p, len);
+
+ return len;
+}
+
+static int
+oserverid(uchar *w, int n, Otab*, Req *r)
+{+ if(n < 4+4+Eaddrlen)
+ return -1;
+ w[0] = 0, w[1] = 1; /* duid type: link layer address + time*/
+ w[2] = 0, w[3] = 1; /* hw type: ethernet */
+ w += 4;
+ w[0] = starttime>>24;
+ w[1] = starttime>>16;
+ w[2] = starttime>>8;
+ w[3] = starttime;
+ w += 4;
+ myetheraddr(w, r->ifc->dev);
+ return 4+4+Eaddrlen;
+}
+
+static int
+oiana(uchar *w, int n, Otab*, Req *r)
+{+ int i, len;
+ uchar *p;
+
+ p = gettlv(3, &len, r->req.p, r->req.e);
+ if(p == nil || len < 3*4)
+ return -1;
+
+ len = 3*4 + (4+IPaddrlen+2*4)*r->nips;
+ if(n < len)
+ return -1;
+
+ memmove(w, p, 3*4);
+ w += 3*4;
+
+ for(i = 0; i < r->nips; i++){+ w[0] = 0, w[1] = 5;
+ w[2] = 0, w[3] = IPaddrlen+2*4;
+ w += 4;
+
+ memmove(w, r->ips + i*IPaddrlen, IPaddrlen);
+ w += IPaddrlen;
+
+ memset(w, 255, 2*4);
+ w += 2*4;
+ }
+
+ return len;
+}
+
+static Ndbtuple*
+lookup(Req *r, char *av[], int ac)
+{+ Ndbtuple *t;
+ char *s;
+
+ if(ac <= 0)
+ return nil;
+
+ t = nil;
+ if(r->nips > 0){+ int i;
+
+ /* use the target ip's to lookup info if any */
+ for(i=0; i<r->nips; i++){+ s = smprint("%I", &r->ips[i*IPaddrlen]);+ t = ndbconcatenate(t, ndbipinfo(r->db, "ip", s, av, ac));
+ free(s);
+ }
+ } else {+ Iplifc *lifc;
+
+ /* use the ipv6 networks on the interface */
+ for(lifc=r->ifc->lifc; lifc!=nil; lifc=lifc->next){+ if(isv4(lifc->ip)
+ || ipcmp(lifc->ip, v6loopback) == 0
+ || ISIPV6LINKLOCAL(lifc->ip))
+ continue;
+ s = smprint("%I", lifc->net);+ t = ndbconcatenate(t, ndbipinfo(r->db, "ip", s, av, ac));
+ free(s);
+ }
+ }
+ return t;
+}
+
+static int
+oro(uchar*, int, Otab *o, Req *r)
+{+ uchar *p;
+ char *av[100];
+ int i, j, l, ac;
+ Ndbtuple *t;
+
+ p = gettlv(6, &l, r->req.p, r->req.e);
+ if(p == nil || l < 2)
+ return -1;
+
+ ac = 0;
+ for(i=0; i<l; i+=2){+ if((o = findotab(p[i]>>8 | p[i+1])) == nil || o->done)
+ continue;
+ for(j=0; j<3 && o->q[j]!=nil && ac<nelem(av); j++)
+ av[ac++] = o->q[j];
+ }
+
+ r->t = lookup(r, av, ac);
+
+ if(debug){+ fprint(2, "ndb(");+ for(t = r->t; t != nil; t = t->entry){+ fprint(2, "%s=%s ", t->attr, t->val);
+ if(t->entry != nil && t->entry != t->line)
+ fprint(2, "\n");
+ }
+ fprint(2, ")\n");
+ }
+
+ /* process the options */
+ for(i=0; i<l; i+=2)
+ addoption(r, p[i]>>8 | p[i+1]);
+
+ ndbfree(r->t);
+ r->t = nil;
+
+ return -1;
+}
+
+static int
+oservers(uchar *w, int n, Otab *o, Req *r)
+{+ return getv6ips(w, n, r->t, o->q[0]);
+}
+
+static int
+odomainlist(uchar *w, int n, Otab *o, Req *q)
+{+ Ndbtuple *t;
+ int l, r;
+ char *s;
+
+ r = 0;
+ for(t = q->t; t != nil; t = t->entry){+ if(strcmp(t->attr, o->q[0]) != 0)
+ continue;
+ for(s = t->val; *s != 0; s++){+ for(l = 0; *s != 0 && *s != '.'; l++)
+ s++;
+ if(r+1+l > n)
+ return -1;
+ w[r++] = l;
+ memmove(w+r, s-l, l);
+ r += l;
+ }
+ if(r >= n)
+ return -1;
+ w[r++] = 0;
+ }
+ return r;
+}
+
+static int
+obootfileurl(uchar *w, int n, Otab *, Req *q)
+{+ uchar ip[IPaddrlen];
+ Ndbtuple *bootf;
+
+ if((bootf = ndbfindattr(q->t, q->t, "bootf")) == nil)
+ return -1;
+ if(strstr(bootf->val, "://") != nil)
+ return snprint((char*)w, n, "%s", bootf->val);
+ else if(getv6ips(ip, sizeof(ip), q->t, "tftp"))
+ return snprint((char*)w, n, "tftp://[%I]/%s", ip, bootf->val);
+ return -1;
+}
+
+static Otab otab[] = {+ { 1, oclientid, },+ { 2, oserverid, },+ { 3, oiana, },+ { 6, oro, },+ { 23, oservers, "@dns" },+ { 24, odomainlist, "dnsdomain" },+ { 59, obootfileurl, "bootf", "@tftp", },+ { 0 },+};
--- a/sys/src/cmd/ip/mkfile
+++ b/sys/src/cmd/ip/mkfile
@@ -2,6 +2,7 @@
TARG = 6in4\
ayiya\
+ dhcp6d\
dhcpclient\
ftpd\
gping\