diff options
Diffstat (limited to 'src/libndb/ndbipinfo.c')
| -rw-r--r-- | src/libndb/ndbipinfo.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/src/libndb/ndbipinfo.c b/src/libndb/ndbipinfo.c new file mode 100644 index 00000000..5cdc24b5 --- /dev/null +++ b/src/libndb/ndbipinfo.c @@ -0,0 +1,242 @@ +#include <u.h> +#include <libc.h> +#include <bio.h> +#include <ndb.h> +#include <ip.h> + +enum +{ + Ffound= 1<<0, + Fignore=1<<1, + Faddr= 1<<2, +}; + +static Ndbtuple* filter(Ndb *db, Ndbtuple *t, Ndbtuple *f); +static Ndbtuple* mkfilter(int argc, char **argv); +static int filtercomplete(Ndbtuple *f); +static Ndbtuple* toipaddr(Ndb *db, Ndbtuple *t); +static int prefixlen(uchar *ip); +static Ndbtuple* subnet(Ndb *db, uchar *net, Ndbtuple *f, int prefix); + +/* make a filter to be used in filter */ +static Ndbtuple* +mkfilter(int argc, char **argv) +{ + Ndbtuple *t, *first, *last; + char *p; + + last = first = nil; + while(argc-- > 0){ + t = ndbnew(0, 0); + if(first) + last->entry = t; + else + first = t; + last = t; + p = *argv++; + if(*p == '@'){ + t->ptr |= Faddr; + p++; + } + strncpy(t->attr, p, sizeof(t->attr)-1); + } + return first; +} + +/* return true if every pair of filter has been used */ +static int +filtercomplete(Ndbtuple *f) +{ + for(; f; f = f->entry) + if((f->ptr & Fignore) == 0) + return 0; + return 1; +} + +/* set the attribute of all entries in a tuple */ +static Ndbtuple* +setattr(Ndbtuple *t, char *attr) +{ + Ndbtuple *nt; + + for(nt = t; nt; nt = nt->entry) + strcpy(nt->attr, attr); + return t; +} + +/* + * return only the attr/value pairs in t maching the filter, f. + * others are freed. line structure is preserved. + */ +static Ndbtuple* +filter(Ndb *db, Ndbtuple *t, Ndbtuple *f) +{ + Ndbtuple *nt, *nf, *next; + + /* filter out what we don't want */ + for(nt = t; nt; nt = next){ + next = nt->entry; + + /* look through filter */ + for(nf = f; nf != nil; nf = nf->entry){ + if(!(nf->ptr&Fignore) && strcmp(nt->attr, nf->attr) == 0) + break; + } + if(nf == nil){ + /* remove nt from t */ + t = ndbdiscard(t, nt); + } else { + if(nf->ptr & Faddr) + t = ndbsubstitute(t, nt, setattr(ndbgetipaddr(db, nt->val), nt->attr)); + nf->ptr |= Ffound; + } + } + + /* remember filter etnries that matched */ + for(nf = f; nf != nil; nf = nf->entry) + if(nf->ptr & Ffound) + nf->ptr = (nf->ptr & ~Ffound) | Fignore; + + return t; +} + +static int +prefixlen(uchar *ip) +{ + int y, i; + + for(y = IPaddrlen-1; y >= 0; y--) + for(i = 8; i > 0; i--) + if(ip[y] & (1<<(8-i))) + return y*8 + i; + return 0; +} + +/* + * look through a containing subset + */ +static Ndbtuple* +subnet(Ndb *db, uchar *net, Ndbtuple *f, int prefix) +{ + Ndbs s; + Ndbtuple *t, *nt, *xt; + char netstr[128]; + uchar mask[IPaddrlen]; + int masklen; + + t = nil; + sprint(netstr, "%I", net); + nt = ndbsearch(db, &s, "ip", netstr); + while(nt != nil){ + xt = ndbfindattr(nt, nt, "ipnet"); + if(xt){ + xt = ndbfindattr(nt, nt, "ipmask"); + if(xt) + parseipmask(mask, xt->val); + else + ipmove(mask, defmask(net)); + masklen = prefixlen(mask); + if(masklen <= prefix) + t = ndbconcatenate(t, filter(db, nt, f)); + } else + ndbfree(nt); + nt = ndbsnext(&s, "ip", netstr); + } + return t; +} + +/* + * fill in all the requested attributes for a system. + * if the system's entry doesn't have all required, + * walk through successively more inclusive networks + * for inherited attributes. + */ +Ndbtuple* +ndbipinfo(Ndb *db, char *attr, char *val, char **alist, int n) +{ + Ndbtuple *t, *nt, *f; + Ndbs s; + char *ipstr; + uchar net[IPaddrlen]; + uchar ip[IPaddrlen]; + int prefix, smallestprefix; + int force; + + /* just in case */ + fmtinstall('I', eipfmt); + fmtinstall('M', eipfmt); + + /* get needed attributes */ + f = mkfilter(n, alist); + + /* + * first look for a matching entry with an ip address + */ + t = nil; + ipstr = ndbgetvalue(db, &s, attr, val, "ip", &nt); + if(ipstr == nil){ + /* none found, make one up */ + if(strcmp(attr, "ip") != 0) + return nil; + t = ndbnew("ip", val); + t->line = t; + t->entry = nil; + parseip(net, val); + } else { + /* found one */ + while(nt != nil){ + nt = ndbreorder(nt, s.t); + t = ndbconcatenate(t, nt); + nt = ndbsnext(&s, attr, val); + } + parseip(net, ipstr); + free(ipstr); + } + ipmove(ip, net); + t = filter(db, t, f); + + /* + * now go through subnets to fill in any missing attributes + */ + if(isv4(net)){ + prefix = 127; + smallestprefix = 100; + force = 0; + } else { + /* in v6, the last 8 bytes have no structure (we hope) */ + prefix = 64; + smallestprefix = 2; + memset(net+8, 0, 8); + force = 1; + } + + /* + * to find a containing network, keep turning off + * the lower bit and look for a network with + * that address and a shorter mask. tedius but + * complete, we may need to find a trick to speed this up. + */ + for(; prefix >= smallestprefix; prefix--){ + if(filtercomplete(f)) + break; + if(!force && (net[prefix/8] & (1<<(7-(prefix%8)))) == 0) + continue; + force = 0; + net[prefix/8] &= ~(1<<(7-(prefix%8))); + t = ndbconcatenate(t, subnet(db, net, f, prefix)); + } + + /* + * if there's an unfulfilled ipmask, make one up + */ + nt = ndbfindattr(f, f, "ipmask"); + if(nt && !(nt->ptr & Fignore)){ + char x[64]; + + snprint(x, sizeof(x), "%M", defmask(ip)); + t = ndbconcatenate(t, ndbnew("ipmask", x)); + } + + ndbfree(f); + return t; +} |