}
-static int inet_rev_parsecomp(const char *p, size_t n) {
- int i= 0;
- if (n > 3) return -1;
+#define REVPARSE_P_L(labnum) \
+ const char *p= dgram + rps->labstart[labnum]; \
+ int l= rps->lablen[labnum]
+ /*
+ * REVPARSE_P_L(int labnum);
+ * expects:
+ * const char *dgram;
+ * const struct revparse_state *rps;
+ * produces:
+ * const char *p; // start of label labnum in dgram
+ * int l; // length of label in dgram
+ */
+
+static bool revparse_check_tail(struct revparse_state *rps,
+ const char *dgram, int nlabels,
+ int bodylen, const char *inarpa) {
+ int i;
- while (n--) {
- if ('0' <= *p && *p <= '9') i= 10*i + *p++ - '0';
- else return -1;
+ if (nlabels != bodylen+2) return 0;
+ for (i=0; i<2; i++) {
+ REVPARSE_P_L(bodylen+i);
+ const char *want= !i ? inarpa : "arpa";
+ if (!adns__labels_equal(p,l, want,strlen(want))) return 0;
}
- return i;
+ return 1;
}
-static void inet_rev_mkaddr(adns_sockaddr *addr, const byte *ipv) {
- struct in_addr *v4 = &addr->inet.sin_addr;
- v4->s_addr= htonl((ipv[3]<<24) | (ipv[2]<<16) |
- (ipv[1]<<8) | (ipv[0]));
+static bool revparse_atoi(const char *p, int l, int base,
+ unsigned max, unsigned *v_r) {
+ if (l>3) return 0;
+ if (l>1 && p[0]=='0') return 0;
+ unsigned v=0;
+ while (l-- > 0) {
+ int tv;
+ int c= ctype_toupper(*p++);
+ if ('0'<=c && c<='9') tv = c-'0';
+ else if ('A'<=c && c<='Z') tv = c-'A'+10;
+ else return 0;
+ if (tv >= base) return 0;
+ v *= base;
+ v += tv;
+ }
+ if (v>max) return 0;
+ *v_r= v;
+ return 1;
}
-static int inet6_rev_parsecomp(const char *p, size_t n) {
- if (n != 1) return -1;
- else if ('0' <= *p && *p <= '9') return *p - '0';
- else if ('a' <= *p && *p <= 'f') return *p - 'a' + 10;
- else if ('A' <= *p && *p <= 'F') return *p - 'a' + 10;
- else return -1;
-}
+static bool revparse_inet(struct revparse_state *rps,
+ const char *dgram, int nlabels,
+ adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
+ if (!revparse_check_tail(rps,dgram,nlabels,4,"in-addr")) return 0;
-static void inet6_rev_mkaddr(adns_sockaddr *addr, const byte *ipv) {
- struct in6_addr *v6 = &addr->inet6.sin6_addr;
- unsigned char *a= v6->s6_addr;
+ uint32_t a=0;
int i;
-
- for (i=0; i<16; i++)
- a[i]= (ipv[31-2*i] << 4) | (ipv[30-2*i] << 0);
+ for (i=3; i>=0; i--) {
+ REVPARSE_P_L(i);
+ unsigned v;
+ if (!revparse_atoi(p,l,10,255,&v)) return 0;
+ a <<= 8;
+ a |= v;
+ }
+ *rrtype_r= adns_r_a;
+ addr_r->inet.sin_family= AF_INET;
+ addr_r->inet.sin_addr.s_addr= htonl(a);
+ return 1;
}
-static const struct revparse_domain {
- int af; /* address family */
- int nrevlab; /* n of reverse-address labels */
- adns_rrtype rrtype; /* forward-lookup type */
+static bool revparse_inet6(struct revparse_state *rps,
+ const char *dgram, int nlabels,
+ adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
+ if (!revparse_check_tail(rps,dgram,nlabels,32,"ip6")) return 0;
- int (*rev_parsecomp)(const char *p, size_t n);
- /* parse a single component from a label; return the integer value, or -1
- * if it was unintelligible.
- */
-
- void (*rev_mkaddr)(adns_sockaddr *addr, const byte *ipv);
- /* write out the parsed protocol address from a vector of parsed components */
-
- const char *const tail[3]; /* tail label names */
-} revparse_domains[NREVDOMAINS] = {
- { AF_INET, 4, adns_r_a, inet_rev_parsecomp, inet_rev_mkaddr,
- { DNS_INADDR_ARPA, 0 } },
- { AF_INET6, 32, adns_r_aaaa, inet6_rev_parsecomp, inet6_rev_mkaddr,
- { DNS_IP6_ARPA, 0 } },
-};
-
-#define REVDOMAIN_MAP(rps, labnum) \
- ((labnum) ? (rps)->map : (1 << NREVDOMAINS) - 1)
-
-int adns__revparse_label(struct revparse_state *rps, int labnum,
- const char *dgram, int labstart, int lablen) {
- const char *label = dgram+labstart;
- unsigned f= REVDOMAIN_MAP(rps, labnum);
- const struct revparse_domain *rpd;
- const char *tp;
- unsigned d;
- int i, ac;
-
- for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
- if (!(f & d)) continue;
- if (labnum >= rpd->nrevlab) {
- tp = rpd->tail[labnum - rpd->nrevlab];
- if (!tp || strncmp(label, tp, lablen) != 0 || tp[lablen])
- goto mismatch;
- } else {
- ac= rpd->rev_parsecomp(label, lablen);
- if (ac < 0) goto mismatch;
- assert(labnum < sizeof(rps->ipv[i]));
- rps->ipv[i][labnum]= ac;
+ int i, j;
+ memset(addr_r,0,sizeof(*addr_r));
+ unsigned char *a= addr_r->inet6.sin6_addr.s6_addr+16;
+ for (i=0; i<32; ) { /* i incremented in inner loop */
+ unsigned b=0;
+ for (j=0; j<2; j++, i++) {
+ REVPARSE_P_L(i);
+ unsigned v;
+ if (!revparse_atoi(p,l,16,15,&v)) return 0;
+ b >>= 4;
+ b |= v << 4;
}
- continue;
-
- mismatch:
- f &= ~d;
- if (!f) return -1;
+ *--a= b;
}
-
- rps->map= f;
- return 0;
+ *rrtype_r= adns_r_aaaa;
+ addr_r->inet.sin_family= AF_INET6;
+ return 1;
}
-int adns__revparse_done(struct revparse_state *rps,
- const char *dgram, int nlabels,
- adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
- unsigned f= REVDOMAIN_MAP(rps, nlabels);
- const struct revparse_domain *rpd;
- unsigned d;
- int i, found= -1;
-
- for (rpd=revparse_domains, i=0, d=1; i<NREVDOMAINS; rpd++, i++, d <<= 1) {
- if (!(f & d)) continue;
- if (nlabels >= rpd->nrevlab && !rpd->tail[nlabels - rpd->nrevlab])
- { found = i; continue; }
- f &= ~d;
- if (!f) return -1;
- }
- assert(found >= 0); assert(f == (1 << found));
+bool adns__revparse_label(struct revparse_state *rps, int labnum,
+ const char *dgram, int labstart, int lablen) {
+ if (labnum >= MAXREVLABELS)
+ return 0;
- rpd= &revparse_domains[found];
- *rrtype_r= rpd->rrtype;
- addr_r->sa.sa_family= rpd->af;
- rpd->rev_mkaddr(addr_r, rps->ipv[found]);
- return 0;
+ assert(labstart <= 65535);
+ assert(lablen <= 255);
+ rps->labstart[labnum] = labstart;
+ rps->lablen[labnum] = lablen;
+ return 1;
+}
+
+bool adns__revparse_done(struct revparse_state *rps,
+ const char *dgram, int nlabels,
+ adns_rrtype *rrtype_r, adns_sockaddr *addr_r) {
+ return
+ revparse_inet(rps,dgram,nlabels,rrtype_r,addr_r) ||
+ revparse_inet6(rps,dgram,nlabels,rrtype_r,addr_r);
}