ref: e0c19ae048ae671883fd4d27d5f617c02020bdf5
dir: /sys/src/cmd/ip/snoopy/bootp.c/
#include <u.h> #include <libc.h> #include <ip.h> #include "dat.h" #include "protos.h" enum { OfferTimeout= 60, /* when an offer times out */ MaxLease= 60*60, /* longest lease for dynamic binding */ MinLease= 15*60, /* shortest lease for dynamic binding */ StaticLease= 30*60, /* lease for static binding */ IPUDPHDRSIZE= 28, /* size of an IP plus UDP header */ MINSUPPORTED= 576, /* biggest IP message the client must support */ /* lengths of some bootp fields */ Maxhwlen= 16, Maxfilelen= 128, Maxoptlen= 312-4, /* bootp types */ Bootrequest= 1, Bootreply= 2, /* bootp flags */ Fbroadcast= 1<<15, }; typedef struct Hdr Hdr; struct Hdr { uchar op; /* opcode */ uchar htype; /* hardware type */ uchar hlen; /* hardware address len */ uchar hops; /* hops */ uchar xid[4]; /* a random number */ uchar secs[2]; /* elapsed since client started booting */ uchar flags[2]; uchar ciaddr[IPv4addrlen]; /* client IP address (client tells server) */ uchar yiaddr[IPv4addrlen]; /* client IP address (server tells client) */ uchar siaddr[IPv4addrlen]; /* server IP address */ uchar giaddr[IPv4addrlen]; /* gateway IP address */ uchar chaddr[Maxhwlen]; /* client hardware address */ char sname[64]; /* server host name (optional) */ char file[Maxfilelen]; /* boot file name */ uchar optmagic[4]; uchar optdata[Maxoptlen]; }; enum { Oca, Osa, Ot, }; static Field p_fields[] = { {"ca", Fv4ip, Oca, "client IP addr", } , {"sa", Fv4ip, Osa, "server IP addr", } , {0} }; #define plan9opt ((ulong)(('p'<<24) | ('9'<<16) | (' '<<8) | ' ')) #define genericopt (0x63825363UL) static Mux p_mux[] = { {"dhcp", genericopt,}, {"plan9bootp", plan9opt,}, {"dump", 0,}, {0} }; static void p_compile(Filter *f) { Mux *m; if(f->op == '='){ compile_cmp(bootp.name, f, p_fields); return; } for(m = p_mux; m->name != nil; m++) if(strcmp(f->s, m->name) == 0){ f->pr = m->pr; f->ulv = m->val; f->subop = Ot; return; } sysfatal("unknown bootp field: %s", f->s); } static int p_filter(Filter *f, Msg *m) { Hdr *h; h = (Hdr*)m->ps; if(m->pe < (uchar*)h->sname) return 0; m->ps = h->optdata; switch(f->subop){ case Oca: return NetL(h->ciaddr) == f->ulv || NetL(h->yiaddr) == f->ulv; case Osa: return NetL(h->siaddr) == f->ulv; case Ot: return NetL(h->optmagic) == f->ulv; } return 0; } static char* op(int i) { static char x[20]; switch(i){ case Bootrequest: return "Req"; case Bootreply: return "Rep"; default: sprint(x, "%d", i); return x; } } static int p_seprint(Msg *m) { Hdr *h; ulong x; h = (Hdr*)m->ps; if(m->pe < (uchar*)h->sname) return -1; /* point past data */ m->ps = h->optdata; /* next protocol */ m->pr = nil; if(m->pe >= (uchar*)h->optdata){ x = NetL(h->optmagic); demux(p_mux, x, x, m, &dump); } m->p = seprint(m->p, m->e, "t=%s ht=%d hl=%d hp=%d xid=%ux sec=%d fl=%4.4ux ca=%V ya=%V sa=%V ga=%V cha=%E magic=%lux", op(h->op), h->htype, h->hlen, h->hops, NetL(h->xid), NetS(h->secs), NetS(h->flags), h->ciaddr, h->yiaddr, h->siaddr, h->giaddr, h->chaddr, (ulong)NetL(h->optmagic)); if(m->pe > (uchar*)h->sname && *h->sname) m->p = seprint(m->p, m->e, " snam=%s", h->sname); if(m->pe > (uchar*)h->file && *h->file) m->p = seprint(m->p, m->e, " file=%s", h->file); return 0; } Proto bootp = { "bootp", p_compile, p_filter, p_seprint, p_mux, "%#.8lux", p_fields, defaultframer, };