diff options
Diffstat (limited to 'src/cmd/ip/snoopy/bootp.c')
-rwxr-xr-x | src/cmd/ip/snoopy/bootp.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/src/cmd/ip/snoopy/bootp.c b/src/cmd/ip/snoopy/bootp.c new file mode 100755 index 00000000..1adfdad1 --- /dev/null +++ b/src/cmd/ip/snoopy/bootp.c @@ -0,0 +1,176 @@ +#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(arp.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, + p_fields, + defaultframer, +}; |