1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include <ndb.h>
5 #include <ip.h>
6
7 enum
8 {
9 Ffound= 1<<0,
10 Fignore=1<<1,
11 Faddr= 1<<2,
12 };
13
14 static Ndbtuple* filter(Ndb *db, Ndbtuple *t, Ndbtuple *f);
15 static Ndbtuple* mkfilter(int argc, char **argv);
16 static int filtercomplete(Ndbtuple *f);
17 static Ndbtuple* toipaddr(Ndb *db, Ndbtuple *t);
18 static int prefixlen(uchar *ip);
19 static Ndbtuple* subnet(Ndb *db, uchar *net, Ndbtuple *f, int prefix);
20
21 /* make a filter to be used in filter */
22 static Ndbtuple*
mkfilter(int argc,char ** argv)23 mkfilter(int argc, char **argv)
24 {
25 Ndbtuple *t, *first, *last;
26 char *p;
27
28 last = first = nil;
29 while(argc-- > 0){
30 t = ndbnew(0, 0);
31 if(first)
32 last->entry = t;
33 else
34 first = t;
35 last = t;
36 p = *argv++;
37 if(*p == '@'){ /* @attr=val ? */
38 t->ptr |= Faddr; /* return resolved address(es) */
39 p++;
40 }
41 strncpy(t->attr, p, sizeof(t->attr)-1);
42 }
43 ndbsetmalloctag(first, getcallerpc(&argc));
44 return first;
45 }
46
47 /* return true if every pair of filter has been used */
48 static int
filtercomplete(Ndbtuple * f)49 filtercomplete(Ndbtuple *f)
50 {
51 for(; f; f = f->entry)
52 if((f->ptr & Fignore) == 0)
53 return 0;
54 return 1;
55 }
56
57 /* set the attribute of all entries in a tuple */
58 static Ndbtuple*
setattr(Ndbtuple * t,char * attr)59 setattr(Ndbtuple *t, char *attr)
60 {
61 Ndbtuple *nt;
62
63 for(nt = t; nt; nt = nt->entry)
64 strcpy(nt->attr, attr);
65 return t;
66 }
67
68 /*
69 * return only the attr/value pairs in t maching the filter, f.
70 * others are freed. line structure is preserved.
71 */
72 static Ndbtuple*
filter(Ndb * db,Ndbtuple * t,Ndbtuple * f)73 filter(Ndb *db, Ndbtuple *t, Ndbtuple *f)
74 {
75 Ndbtuple *nt, *nf, *next;
76
77 /* filter out what we don't want */
78 for(nt = t; nt; nt = next){
79 next = nt->entry;
80
81 /* look through filter */
82 for(nf = f; nf != nil; nf = nf->entry){
83 if(!(nf->ptr&Fignore) && strcmp(nt->attr, nf->attr) == 0)
84 break;
85 }
86 if(nf == nil){
87 /* remove nt from t */
88 t = ndbdiscard(t, nt);
89 } else {
90 if(nf->ptr & Faddr)
91 t = ndbsubstitute(t, nt, setattr(ndbgetipaddr(db, nt->val), nt->attr));
92 nf->ptr |= Ffound;
93 }
94 }
95
96 /* remember filter etnries that matched */
97 for(nf = f; nf != nil; nf = nf->entry)
98 if(nf->ptr & Ffound)
99 nf->ptr = (nf->ptr & ~Ffound) | Fignore;
100
101 ndbsetmalloctag(t, getcallerpc(&db));
102 return t;
103 }
104
105 static int
prefixlen(uchar * ip)106 prefixlen(uchar *ip)
107 {
108 int y, i;
109
110 for(y = IPaddrlen-1; y >= 0; y--)
111 for(i = 8; i > 0; i--)
112 if(ip[y] & (1<<(8-i)))
113 return y*8 + i;
114 return 0;
115 }
116
117 /*
118 * look through a containing subset
119 */
120 static Ndbtuple*
subnet(Ndb * db,uchar * net,Ndbtuple * f,int prefix)121 subnet(Ndb *db, uchar *net, Ndbtuple *f, int prefix)
122 {
123 Ndbs s;
124 Ndbtuple *t, *nt, *xt;
125 char netstr[128];
126 uchar mask[IPaddrlen];
127 int masklen;
128
129 t = nil;
130 snprint(netstr, sizeof netstr, "%I", net);
131 nt = ndbsearch(db, &s, "ip", netstr);
132 while(nt != nil){
133 xt = ndbfindattr(nt, nt, "ipnet");
134 if(xt){
135 xt = ndbfindattr(nt, nt, "ipmask");
136 if(xt)
137 parseipmask(mask, xt->val);
138 else
139 ipmove(mask, defmask(net));
140 masklen = prefixlen(mask);
141 if(masklen <= prefix){
142 t = ndbconcatenate(t, filter(db, nt, f));
143 nt = nil;
144 }
145 }
146 ndbfree(nt);
147 nt = ndbsnext(&s, "ip", netstr);
148 }
149 ndbsetmalloctag(t, getcallerpc(&db));
150 return t;
151 }
152
153 /*
154 * fill in all the requested attributes for a system.
155 * if the system's entry doesn't have all required,
156 * walk through successively more inclusive networks
157 * for inherited attributes.
158 */
159 Ndbtuple*
ndbipinfo(Ndb * db,char * attr,char * val,char ** alist,int n)160 ndbipinfo(Ndb *db, char *attr, char *val, char **alist, int n)
161 {
162 Ndbtuple *t, *nt, *f;
163 Ndbs s;
164 char *ipstr;
165 uchar net[IPaddrlen], ip[IPaddrlen];
166 int prefix, smallestprefix, force;
167 vlong r;
168
169 /* just in case */
170 fmtinstall('I', eipfmt);
171 fmtinstall('M', eipfmt);
172
173 /* get needed attributes */
174 f = mkfilter(n, alist);
175
176 /*
177 * first look for a matching entry with an ip address
178 */
179 t = nil;
180 ipstr = ndbgetvalue(db, &s, attr, val, "ip", &nt);
181 if(ipstr == nil){
182 /* none found, make one up */
183 if(strcmp(attr, "ip") != 0) {
184 ndbfree(f);
185 return nil;
186 }
187 t = ndbnew("ip", val);
188 t->line = t;
189 t->entry = nil;
190 r = parseip(net, val);
191 if(r == -1)
192 ndbfree(t);
193 } else {
194 /* found one */
195 while(nt != nil){
196 nt = ndbreorder(nt, s.t);
197 t = ndbconcatenate(t, nt);
198 nt = ndbsnext(&s, attr, val);
199 }
200 r = parseip(net, ipstr);
201 free(ipstr);
202 }
203 if(r < 0){
204 ndbfree(f);
205 return nil;
206 }
207 ipmove(ip, net);
208 t = filter(db, t, f);
209
210 /*
211 * now go through subnets to fill in any missing attributes
212 */
213 if(isv4(net)){
214 prefix = 127;
215 smallestprefix = 100;
216 force = 0;
217 } else {
218 /* in v6, the last 8 bytes have no structure (we hope) */
219 prefix = 64;
220 smallestprefix = 2;
221 memset(net+8, 0, 8);
222 force = 1;
223 }
224
225 /*
226 * to find a containing network, keep turning off
227 * the lower bit and look for a network with
228 * that address and a shorter mask. tedius but
229 * complete, we may need to find a trick to speed this up.
230 */
231 for(; prefix >= smallestprefix; prefix--){
232 if(filtercomplete(f))
233 break;
234 if(!force && (net[prefix/8] & (1<<(7-(prefix%8)))) == 0)
235 continue;
236 force = 0;
237 net[prefix/8] &= ~(1<<(7-(prefix%8)));
238 t = ndbconcatenate(t, subnet(db, net, f, prefix));
239 }
240
241 /*
242 * if there's an unfulfilled ipmask, make one up
243 */
244 nt = ndbfindattr(f, f, "ipmask");
245 if(nt && !(nt->ptr & Fignore)){
246 char x[64];
247
248 snprint(x, sizeof(x), "%M", defmask(ip));
249 t = ndbconcatenate(t, ndbnew("ipmask", x));
250 }
251
252 ndbfree(f);
253 ndbsetmalloctag(t, getcallerpc(&db));
254 return t;
255 }
256