+/* The 'ipset' data structure and related algorithms in this file were
+ inspired by the 'ipaddr.py' library from Cendio Systems AB. */
+
#include "secnet.h"
+#include <limits.h>
+#include <assert.h>
#include <stdio.h>
+#include <string.h>
+#include "ipaddr.h"
+
+#define DEFAULT_ALLOC 2
+#define EXTEND_ALLOC_BY 4
-/* This file should eventually incorporate all the functionality of
- ipaddr.py */
+struct subnet_list *subnet_list_new(void)
+{
+ struct subnet_list *r;
+ r=safe_malloc(sizeof(*r),"subnet_list_new:list");
+ r->entries=0;
+ r->alloc=DEFAULT_ALLOC;
+ r->list=safe_malloc_ary(sizeof(*r->list),r->alloc,"subnet_list_new:data");
+ return r;
+}
-bool_t subnet_match(struct subnet *s, uint32_t address)
+void subnet_list_free(struct subnet_list *a)
{
- return (s->prefix==(address&s->mask));
+ if (a->list) free(a->list);
+ free(a);
}
-bool_t subnet_matches_list(struct subnet_list *list, uint32_t address)
+static void subnet_list_set_len(struct subnet_list *a, int32_t l)
{
- uint32_t i;
- for (i=0; i<list->entries; i++) {
- if (list->list[i].prefix == (address&list->list[i].mask)) return True;
+ struct subnet *nd;
+ int32_t na;
+
+ if (l>a->alloc) {
+ assert(a->alloc < (int)(INT_MAX/sizeof(*nd))-EXTEND_ALLOC_BY);
+ na=a->alloc+EXTEND_ALLOC_BY;
+ nd=realloc(a->list,sizeof(*nd)*na);
+ if (!nd) {
+ fatal_perror("subnet_list_set_len: realloc");
+ }
+ a->alloc=na;
+ a->list=nd;
}
- return False;
+ a->entries=l;
+}
+
+void subnet_list_append(struct subnet_list *a, uint32_t prefix, int len)
+{
+ struct subnet *sn;
+ assert(a->entries < INT_MAX);
+ subnet_list_set_len(a,a->entries+1);
+ sn=&a->list[a->entries-1];
+ sn->prefix=prefix;
+ sn->len=len;
+ sn->mask=len?(0xffffffff << (32-len)):0;
+}
+
+struct ipset *ipset_new(void)
+{
+ struct ipset *r;
+ r=safe_malloc(sizeof(*r),"ipset_new:set");
+ r->l=0;
+ r->a=DEFAULT_ALLOC;
+ r->d=safe_malloc(sizeof(*r->d)*r->a,"ipset_new:data");
+ return r;
}
-bool_t subnets_intersect(struct subnet a, struct subnet b)
+void ipset_free(struct ipset *a)
{
- uint32_t mask=a.mask&b.mask;
- return ((a.prefix&mask)==(b.prefix&mask));
+ if (a->d) free(a->d);
+ free(a);
}
-bool_t subnet_intersects_with_list(struct subnet a, struct subnet_list *b)
+#ifdef DEBUG
+static void ipset_dump(struct ipset *a, string_t name)
{
- uint32_t i;
+ int32_t i;
- for (i=0; i<b->entries; i++) {
- if (subnets_intersect(a,b->list[i])) return True;
+ printf("%s: ",name);
+ for (i=0; i<a->l; i++) {
+ printf("[%08x-%08x] ",a->d[i].a,a->d[i].b);
}
- return False;
+ printf("\n");
+}
+#endif
+
+struct ipset *ipset_from_subnet(struct subnet s)
+{
+ struct ipset *r;
+
+ r=ipset_new();
+ r->l=1;
+ r->d[0].a=s.prefix;
+ r->d[0].b=s.prefix | (~s.mask);
+ return r;
+}
+
+struct ipset *ipset_from_subnet_list(struct subnet_list *l)
+{
+ struct ipset *r, *a, *b;
+ int32_t i;
+
+ r=ipset_new();
+ for (i=0; i<l->entries; i++) {
+ a=ipset_from_subnet(l->list[i]);
+ b=ipset_union(r,a);
+ ipset_free(a);
+ ipset_free(r);
+ r=b;
+ }
+ return r;
+}
+
+static void ipset_set_len(struct ipset *a, int32_t l)
+{
+ struct iprange *nd;
+ int32_t na;
+
+ if (l>a->a) {
+ assert(a->a < INT_MAX-EXTEND_ALLOC_BY);
+ na=a->a+EXTEND_ALLOC_BY;
+ nd=realloc(a->d,sizeof(*nd)*na);
+ if (!nd) {
+ fatal_perror("ipset_set_len: realloc");
+ }
+ a->a=na;
+ a->d=nd;
+ }
+ a->l=l;
+}
+
+static void ipset_append_range(struct ipset *a, struct iprange r)
+{
+ ipset_set_len(a,a->l+1);
+ a->d[a->l-1]=r;
+}
+
+#define max(a,b) (a>b?a:b)
+struct ipset *ipset_union(struct ipset *a, struct ipset *b)
+{
+ struct ipset *c;
+ struct iprange r;
+ int32_t ia,ib;
+
+ c=ipset_new();
+ ia=0; ib=0;
+ while (ia<a->l || ib<b->l) {
+ if (ia<a->l)
+ if (ib<b->l)
+ if (a->d[ia].a < b->d[ib].a)
+ r=a->d[ia++];
+ else
+ r=b->d[ib++];
+ else
+ r=a->d[ia++];
+ else
+ r=b->d[ib++];
+
+ if (c->l==0)
+ ipset_append_range(c,r);
+ else if (r.a <= c->d[c->l-1].b+1)
+ /* Extends (or is consumed by) the last range */
+ c->d[c->l-1].b=max(c->d[c->l-1].b, r.b);
+ else
+ ipset_append_range(c,r);
+ }
+ return c;
+}
+
+struct ipset *ipset_intersection(struct ipset *a, struct ipset *b)
+{
+ struct ipset *r;
+ struct iprange ra, rb;
+ int32_t ia,ib;
+
+ r=ipset_new();
+ ia=0; ib=0;
+
+ while (ia<a->l && ib<b->l) {
+ ra=a->d[ia];
+ rb=b->d[ib];
+ if (ra.b < rb.a)
+ /* The first entry of a doesn't overlap with any part of b */
+ ia++;
+ else if (ra.a > rb.b)
+ /* The first entry of b doesn't overlap with any part of a */
+ ib++;
+ else {
+ /* Trim away any leading edges */
+ if (ra.a < rb.a)
+ /* a starts before b */
+ ra.a=rb.a;
+ else if (ra.a > rb.a)
+ /* b starts before a */
+ rb.a=ra.a;
+
+ /* Now the ranges start at the same point */
+ if (ra.b == rb.b) {
+ /* The ranges are equal */
+ ipset_append_range(r,ra);
+ ia++;
+ ib++;
+ } else if (ra.b < rb.b) {
+ /* a is the smaller range */
+ ipset_append_range(r,ra);
+ ia++;
+ } else {
+ /* y is the smaller range */
+ ipset_append_range(r,rb);
+ ib++;
+ }
+ }
+ }
+ return r;
+}
+
+struct ipset *ipset_complement(struct ipset *a)
+{
+ struct ipset *r;
+ struct iprange n;
+ int64_t pre;
+ int32_t i;
+ uint32_t lo,hi;
+
+ r=ipset_new();
+ pre=-1;
+ for (i=0; i<a->l; i++) {
+ lo=a->d[i].a;
+ hi=a->d[i].b;
+ if (lo!=0) {
+ n.a=pre+1;
+ n.b=lo-1;
+ ipset_append_range(r,n);
+ }
+ pre=hi;
+ }
+ if (pre!=0xffffffff) {
+ n.a=pre+1;
+ n.b=0xffffffff;
+ ipset_append_range(r,n);
+ }
+ return r;
+}
+
+/* Return a-b */
+struct ipset *ipset_subtract(struct ipset *a, struct ipset *b)
+{
+ struct ipset *c, *r;
+ c=ipset_complement(b);
+ r=ipset_intersection(a,c);
+ ipset_free(c);
+ return r;
}
-bool_t subnet_lists_intersect(struct subnet_list *a, struct subnet_list *b)
+bool_t ipset_is_empty(struct ipset *a)
{
- uint32_t i;
- for (i=0; i<a->entries; i++) {
- if (subnet_intersects_with_list(a->list[i],b)) return True;
+ return (a->l==0);
+}
+
+bool_t ipset_contains_addr(struct ipset *a, uint32_t addr)
+{
+ int32_t i;
+ struct iprange r;
+
+ for (i=0; i<a->l; i++) {
+ r=a->d[i];
+ if (addr>=r.a && addr<=r.b) return True;
+ if (addr<r.a) return False;
}
return False;
}
+/* sub is a subset of super if it does not intersect with the complement
+ of super */
+bool_t ipset_is_subset(struct ipset *super, struct ipset *sub)
+{
+ struct ipset *superc;
+ struct ipset *inter;
+ bool_t empty;
+
+ superc=ipset_complement(super);
+ inter=ipset_intersection(superc,sub);
+ empty=ipset_is_empty(inter);
+ ipset_free(inter);
+ ipset_free(superc);
+ return empty;
+}
+
+struct subnet_list *ipset_to_subnet_list(struct ipset *is)
+{
+ struct subnet_list *r;
+ int64_t a,b,lobit,himask,lomask;
+ int bits;
+ int32_t i;
+
+ r=subnet_list_new();
+ for (i=0; i<is->l; i++) {
+ a=is->d[i].a;
+ b=is->d[i].b;
+
+ lomask=1;
+ lobit=1;
+ himask=0xfffffffe;
+ bits=32;
+ while (a<=b) {
+ if ((a & lomask) != 0) {
+ subnet_list_append(r,a,bits);
+ a=a+lobit;
+ } else if ((b & lomask) != lomask) {
+ subnet_list_append(r,b&himask,bits);
+ b=b-lobit;
+ } else {
+ lomask = (lomask << 1) | 1;
+ lobit = (lobit << 1);
+ himask = himask ^ lobit;
+ bits = bits - 1;
+ ASSERT(bits>=0);
+ }
+ }
+ }
+ /* Sort the list? */
+ return r;
+}
+
/* The string buffer must be at least 16 bytes long */
string_t ipaddr_to_string(uint32_t addr)
{
return s;
}
-string_t subnet_to_string(struct subnet *sn)
+string_t subnet_to_string(struct subnet sn)
{
- uint32_t mask=sn->mask, addr=sn->prefix;
+ uint32_t addr=sn.prefix;
uint8_t a,b,c,d;
string_t s;
- int i;
s=safe_malloc(19,"subnet_to_string");
a=addr>>24;
b=addr>>16;
c=addr>>8;
d=addr;
- for (i=0; mask; i++) {
- mask=(mask<<1);
+ snprintf(s, 19, "%d.%d.%d.%d/%d", a, b, c, d, sn.len);
+ return s;
+}
+
+static struct subnet string_item_to_subnet(item_t *i, cstring_t desc,
+ bool_t *invert)
+{
+ struct subnet s;
+ uint32_t a, b, c, d, n;
+ int match;
+ cstring_t in;
+
+ *invert=False;
+
+ /* i is not guaranteed to be a string */
+ if (i->type!=t_string) {
+ cfgfatal(i->loc,desc,"expecting a string (subnet specification)\n");
+ }
+ in=i->data.string;
+
+ if (strcmp(in,"default")==0) {
+ s.prefix=0;
+ s.mask=0;
+ s.len=0;
+ return s;
+ }
+
+ if (*in=='!') {
+ *invert=True;
+ in++;
+ }
+ /* We expect strings of the form "a.b.c.d[/n]", i.e. the dots are
+ NOT optional. The subnet mask is optional; if missing it is assumed
+ to be /32. */
+ match=sscanf(in,"%u.%u.%u.%u/%u", &a, &b, &c, &d, &n);
+ if (match<4) {
+ cfgfatal(i->loc,desc,"\"%s\" is not a valid "
+ "subnet specification\n",in);
+ }
+ if (match<5) {
+ n=32;
}
- if (i!=sn->len) {
- fatal("subnet_to_string: invalid subnet structure "
- "(i=%d sn->len=%d mask=0x%08x)!\n",i,sn->len,sn->mask);
+ if (a>255 || b>255 || c>255 || d>255 || n>32) {
+ cfgfatal(i->loc,desc,"\"%s\": range error\n",in);
+ }
+ s.prefix=(a<<24)|(b<<16)|(c<<8)|(d);
+ s.mask=n?(~0UL << (32-n)):0;
+ s.len=n;
+ if (s.prefix & ~s.mask) {
+ cfgfatal(i->loc,desc,"\"%s\": prefix not fully contained "
+ "in mask\n",in);
}
- snprintf(s, 19, "%d.%d.%d.%d/%d", a, b, c, d, sn->len);
return s;
}
+
+uint32_t string_item_to_ipaddr(item_t *i, cstring_t desc)
+{
+ uint32_t a, b, c, d;
+ int match;
+
+ /* i is not guaranteed to be a string */
+ if (i->type!=t_string) {
+ cfgfatal(i->loc,desc,"expecting a string (IP address)\n");
+ }
+
+ match=sscanf(i->data.string,"%u.%u.%u.%u", &a, &b, &c, &d);
+ if (match<4) {
+ cfgfatal(i->loc,desc,"\"%s\" is not a valid "
+ "IP address\n",i->data.string);
+ }
+ if (a>255 || b>255 || c>255 || d>255) {
+ cfgfatal(i->loc,desc,"\"%s\": range error\n",i->data.string);
+ }
+ return (a<<24)|(b<<16)|(c<<8)|(d);
+}
+
+struct ipset *string_list_to_ipset(list_t *l, struct cloc loc,
+ cstring_t module, cstring_t param)
+{
+ struct ipset *r, *n, *isn;
+ uint32_t e,i;
+ item_t *item;
+ bool_t inv;
+
+ r=ipset_new();
+ e=list_length(l);
+ for (i=0; i<e; i++) {
+ item=list_elem(l,i);
+ isn=ipset_from_subnet(string_item_to_subnet(item,param,&inv));
+ if (inv) {
+ n=ipset_subtract(r,isn);
+ } else {
+ n=ipset_union(r,isn);
+ }
+ ipset_free(r);
+ ipset_free(isn);
+ r=n;
+ }
+ return r;
+}
~ian / secnet.git / blobdiff