1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
|
#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 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;
}
|