/*
* look through a containing subset
*/
static Ndbtuple*
subnet(Ndb *db, uint8_t *net, Ndbtuple *f, int prefix)
{
Ndbs s;
Ndbtuple *t, *nt, *xt;
char netstr[128];
uint8_t 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));
nt = nil;
}
}
ndbfree(nt);
nt = ndbsnext(&s, "ip", netstr);
}
ndbsetmalloctag(t, getcallerpc(&db));
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;
ndbsetmalloctag(t, getcallerpc(&db));
return t;
}
/*
* parse the next entry in the file
*/
struct ndbtuple*
ndbparse(struct ndb *db)
{
char *line;
struct ndbtuple *t;
struct ndbtuple *first, *last;
int len;
first = last = 0;
for(;;){
if((line = fgets(db->buf, sizeof(db->buf),db->b)) == 0)
break;
len = strlen(db->buf);
if(line[len-1] != '\n')
break;
if(first && !isspace(*line) && *line != '#'){
fseek(db->b, -len, 1);
break;
}
t = _ndbparseline(line);
if(t == 0)
continue;
if(first)
last->entry = t;
else
first = t;
last = t;
while(last->entry)
last = last->entry;
}
ndbsetmalloctag(first, getcallerpc(&db));
return first;
}
/*
* parse all tuples in a line. we assume that the
* line ends in a '\n'.
*
* the tuples are linked as a list using ->entry and
* as a ring using ->line.
*/
Ndbtuple*
_ndbparseline(char *cp)
{
Ndbtuple *t;
Ndbtuple *first, *last;
first = last = 0;
while(*cp != '#' && *cp != '\n'){
t = 0;
cp = _ndbparsetuple(cp, &t);
if(cp == 0)
break;
if(first){
last->line = t;
last->entry = t;
} else
first = t;
last = t;
t->line = 0;
t->entry = 0;
setmalloctag(t, getcallerpc());
}
if(first)
last->line = first;
ndbsetmalloctag(first, getcallerpc());
return first;
}
/*
* search for a tuple that has the given 'attr=val' and also 'rattr=x'.
* copy 'x' into 'buf' and return the whole tuple.
*
* return 0 if not found.
*/
Ndbtuple*
dnsquery(char *net, char *val, char *type)
{
char rip[128];
char *p;
Ndbtuple *t;
int fd;
/* if the address is V4 or V6 null address, give up early */
if(strcmp(val, "::") == 0 || strcmp(val, "0.0.0.0") == 0)
return nil;
if(net == nil)
net = "/net";
snprint(rip, sizeof(rip), "%s/dns", net);
fd = open(rip, ORDWR);
if(fd < 0) {
if(strcmp(net, "/net") == 0)
snprint(rip, sizeof(rip), "/srv/dns");
else {
snprint(rip, sizeof(rip), "/srv/dns%s", net);
p = strrchr(rip, '/');
*p = '_';
}
fd = open(rip, ORDWR);
if(fd < 0)
return nil;
if(mount(fd, -1, net, MBEFORE, "") < 0) {
close(fd);
return nil;
}
/* fd is now closed */
snprint(rip, sizeof(rip), "%s/dns", net);
fd = open(rip, ORDWR);
if(fd < 0)
return nil;
}
/* zero out the error string */
werrstr("");
/* if this is a reverse lookup, first lookup the domain name */
if(strcmp(type, "ptr") == 0) {
mkptrname(val, rip, sizeof rip);
t = doquery(fd, rip, "ptr");
} else
t = doquery(fd, val, type);
/*
* TODO: make fd static and keep it open to reduce 9P traffic
* walking to /net*^/dns.
*/
close(fd);
ndbsetmalloctag(t, getcallerpc(&net));
return t;
}
/* return list of ip addresses for a name */
Ndbtuple*
ndbgetipaddr(Ndb *db, char *val)
{
char *attr, *p;
Ndbtuple *it, *first, *last, *next;
Ndbs s;
/* already an IP address? */
attr = ipattr(val);
if(strcmp(attr, "ip") == 0){
it = ndbnew("ip", val);
ndbsetmalloctag(it, getcallerpc(&db));
return it;
}
/* look it up */
p = ndbgetvalue(db, &s, attr, val, "ip", &it);
if(p == nil)
return nil;
free(p);
/* remove the non-ip entries */
first = last = nil;
for(; it; it = next){
next = it->entry;
if(strcmp(it->attr, "ip") == 0){
if(first == nil)
first = it;
else
last->entry = it;
it->entry = nil;
it->line = first;
last = it;
} else {
it->entry = nil;
ndbfree(it);
}
}
ndbsetmalloctag(first, getcallerpc(&db));
return first;
}
static Ndbtuple*
doquery(int fd, char *dn, char *type)
{
char buf[1024];
int n;
Ndbtuple *t, *first, *last;
seek(fd, 0, 0);
snprint(buf, sizeof(buf), "!%s %s", dn, type);
if(write(fd, buf, strlen(buf)) < 0)
return nil;
seek(fd, 0, 0);
first = last = nil;
for(;;) {
n = read(fd, buf, sizeof(buf)-2);
if(n <= 0)
break;
if(buf[n-1] != '\n')
buf[n++] = '\n'; /* ndbparsline needs a trailing new line */
buf[n] = 0;
/* check for the error condition */
if(buf[0] == '!') {
werrstr("%s", buf+1);
return nil;
}
t = _ndbparseline(buf);
if(t != nil) {
if(first)
last->entry = t;
else
first = t;
last = t;
while(last->entry)
last = last->entry;
}
}
ndbsetmalloctag(first, getcallerpc(&fd));
return first;
}
/*
* allocate a tuple
*/
struct ndbtuple*
ndbnew(char *attr, char *val)
{
struct ndbtuple *t;
t = calloc(1, sizeof(*t));
if(t == NULL){
fprintf(stderr, "ndbnew %r");
exit(1);
}
if(attr != NULL)
strncpy(t->attr, attr, sizeof(t->attr)-1);
t->val = t->valbuf;
if(val != NULL)
ndbsetval(t, val, strlen(val));
ndbsetmalloctag(t, getcallerpc(&attr));
return t;
}
struct ndbtuple*
ndbgetval(struct ndb *db,
struct ndbs *s, char *attr, char *val, char *rattr, char *buf)
{
struct ndbtuple *t;
char *p;
p = ndbgetvalue(db, s, attr, val, rattr, &t);
if(p == NULL){
if(buf != NULL)
*buf = 0;
} else {
if(buf != NULL){
strncpy(buf, p, Ndbvlen-1);
buf[Ndbvlen-1] = 0;
}
free(p);
}
ndbsetmalloctag(t, getcallerpc(&db));
return t;
}
static Ndbtuple*
ndbcopy(Ndb *db, Ndbtuple *from_t, Ndbs *from_s, Ndbs *to_s)
{
Ndbtuple *first, *to_t, *last, *line;
int newline;
*to_s = *from_s;
to_s->t = nil;
to_s->db = db;
newline = 1;
last = nil;
first = nil;
line = nil;
for(; from_t != nil; from_t = from_t->entry){
to_t = ndbnew(from_t->attr, from_t->val);
/* have s point to matching tuple */
if(from_s->t == from_t)
to_s->t = to_t;
if(newline)
line = to_t;
else
last->line = to_t;
if(last != nil)
last->entry = to_t;
else {
first = to_t;
line = to_t;
}
to_t->entry = nil;
to_t->line = line;
last = to_t;
newline = from_t->line != from_t->entry;
}
ndbsetmalloctag(first, getcallerpc(&db));
return first;
}
/* 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 == '@'){ /* @attr=val ? */
t->ptr |= Faddr; /* return resolved address(es) */
p++;
}
strncpy(t->attr, p, sizeof(t->attr)-1);
}
ndbsetmalloctag(first, getcallerpc(&argc));
return first;
}
/* remove a from t and free it */
struct ndbtuple*
ndbdiscard(struct ndbtuple *t, struct ndbtuple *a)
{
struct ndbtuple *nt;
/* unchain a */
for(nt = t; nt != NULL; nt = nt->entry){
if(nt->line == a)
nt->line = a->line;
if(nt->entry == a)
nt->entry = a->entry;
}
/* a may be start of chain */
if(t == a)
t = a->entry;
/* free a */
a->entry = NULL;
ndbfree(a);
ndbsetmalloctag(t, getcallerpc(&t));
return t;
}
Ndbtuple*
_ndbcacheadd(Ndb *db, Ndbs *s, char *attr, char *val, Ndbtuple *t)
{
Ndbcache *c, **l;
c = mallocz(sizeof *c, 1);
if(c == nil)
return nil;
c->attr = strdup(attr);
if(c->attr == nil)
goto err;
c->val = strdup(val);
if(c->val == nil)
goto err;
c->t = ndbcopy(db, t, s, &c->s);
if(c->t == nil && t != nil)
goto err;
/* add to front */
c->next = db->cache;
db->cache = c;
/* trim list */
if(db->ncache < Maxcached){
db->ncache++;
return t;
}
for(l = &db->cache; (*l)->next; l = &(*l)->next)
;
c = *l;
*l = nil;
err:
ndbcachefree(c);
ndbsetmalloctag(t, getcallerpc(&db));
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;
uint8_t net[IPaddrlen], ip[IPaddrlen];
int prefix, smallestprefix, force;
int64_t r;
/* 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) {
ndbfree(f);
return nil;
}
t = ndbnew("ip", val);
t->line = t;
t->entry = nil;
r = parseip(net, val);
if(r == -1)
ndbfree(t);
} else {
/* found one */
while(nt != nil){
nt = ndbreorder(nt, s.t);
t = ndbconcatenate(t, nt);
nt = ndbsnext(&s, attr, val);
}
r = parseip(net, ipstr);
free(ipstr);
}
if(r < 0){
ndbfree(f);
return nil;
}
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);
ndbsetmalloctag(t, getcallerpc(&db));
return t;
}
/*
* look up the ip attributes 'list' for an entry that has the
* given 'attr=val' and a 'ip=' tuples.
*
* return NULL if not found.
*/
struct ndbtuple*
csipinfo(char *netroot, char *attr, char *val, char **list, int n)
{
struct ndbtuple *t, *first, *last;
int i;
char line[1024];
int fd;
char *p, *e;
int left,amt;
if(netroot)
snprintf(line, sizeof(line), "%s/cs", netroot);
else
strcpy(line, "/net/cs");
fd = open(line, O_RDWR);
if(fd < 0)
return 0;
lseek(fd, 0, 0);
left = sizeof(line);
amt = snprintf(line, left, "!ipinfo %s=%s", attr, val);
if(amt < 0)
return 0;
left -= amt;
for(i = 0; i < n; i++){
if(*list == NULL)
break;
amt = snprintf(p, left, " %s", *list++);
if(amt < 0)
return 0;
left -= amt;
}
if(write(fd, line, strlen(line)) < 0){
close(fd);
return 0;
}
lseek(fd, 0, 0);
first = last = 0;
for(;;){
n = read(fd, line, sizeof(line)-2);
if(n <= 0)
break;
line[n] = '\n';
line[n+1] = 0;
t = _ndbparseline(line);
if(t == 0)
continue;
if(first)
last->entry = t;
else
first = t;
last = t;
while(last->entry)
last = last->entry;
}
close(fd);
ndbsetmalloctag(first, getcallerpc(&netroot));
return first;
}