DOH: add test case 1650 and 2100

2 files changed, 92 insertions, 65 deletions

diff --git a/lib/doh.c b/lib/doh.c
index 5d1cd3b78..33b3e06c9 100644
--- a/lib/doh.c
+++ b/lib/doh.c
@@ -38,31 +38,6 @@
 #define DNS_CLASS_IN 0x01
 #define DOH_MAX_RESPONSE_SIZE 3000 /* bytes */
 
-typedef enum {
-  DNS_TYPE_A = 1,
-  DNS_TYPE_NS = 2,
-  DNS_TYPE_CNAME = 5,
-  DNS_TYPE_AAAA = 28
-} DNStype;
-
-#define MAX_ADDR 24
-
-typedef enum {
-  DOH_OK,
-  DOH_DNS_BAD_LABEL,    /* 1 */
-  DOH_DNS_OUT_OF_RANGE, /* 2 */
-  DOH_DNS_LABEL_LOOP,   /* 3 */
-  DOH_TOO_SMALL_BUFFER, /* 4 */
-  DOH_OUT_OF_MEM,       /* 5 */
-  DOH_DNS_RDATA_LEN,    /* 6 */
-  DOH_DNS_MALFORMAT,    /* 7 */
-  DOH_DNS_BAD_RCODE,    /* 8 - no such name */
-  DOH_DNS_UNEXPECTED_TYPE,  /* 9 */
-  DOH_DNS_UNEXPECTED_CLASS, /* 10 */
-  DOH_NO_CONTENT,           /* 11 */
-  DOH_DNS_BAD_ID            /* 12 */
-} DOHcode;
-
 static const char * const errors[]={
   "",
   "Bad label",
@@ -86,11 +61,17 @@ static const char *doh_strerror(DOHcode code)
   return "bad error code";
 }
 
-static DOHcode doh_encode(const char *host,
-                          DNStype dnstype,
-                          unsigned char *dnsp, /* buffer */
-                          size_t len,  /* buffer size */
-                          size_t *olen) /* output length */
+#ifdef DEBUGBUILD
+#define UNITTEST
+#else
+#define UNITTEST static
+#endif
+
+UNITTEST DOHcode doh_encode(const char *host,
+                            DNStype dnstype,
+                            unsigned char *dnsp, /* buffer */
+                            size_t len,  /* buffer size */
+                            size_t *olen) /* output length */
 {
   size_t hostlen = strlen(host);
   unsigned char *orig = dnsp;
@@ -123,9 +104,11 @@ static DOHcode doh_encode(const char *host,
     }
     else
       labellen = strlen(hostp);
-    if(labellen > 63)
+    if(labellen > 63) {
       /* too long label, error out */
+      *olen = 0;
       return DOH_DNS_BAD_LABEL;
+    }
     *dnsp++ = (unsigned char)labellen;
     memcpy(dnsp, hostp, labellen);
     dnsp += labellen;
@@ -363,36 +346,10 @@ static unsigned int get32bit(unsigned char *doh, int index)
     (doh[index + 2] << 8) | doh[index + 3];
 }
 
-struct addr6 {
-  unsigned char byte[16];
-};
-
-struct cnamestore {
-  size_t len;       /* length of cname */
-  char *alloc;      /* allocated pointer */
-  size_t allocsize; /* allocated size */
-};
-
-struct dohaddr {
-  int type;
-  union {
-    unsigned int v4;
-    struct addr6 v6;
-  } ip;
-};
-
-struct dohentry {
-  unsigned int ttl;
-  int numaddr;
-  struct dohaddr addr[MAX_ADDR];
-  int numcname;
-  struct cnamestore cname[MAX_ADDR];
-};
-
 static DOHcode store_a(unsigned char *doh, int index, struct dohentry *d)
 {
   /* silently ignore addresses over the limit */
-  if(d->numaddr < MAX_ADDR) {
+  if(d->numaddr < DOH_MAX_ADDR) {
     struct dohaddr *a = &d->addr[d->numaddr];
     a->type = DNS_TYPE_A;
     a->ip.v4 = ntohl(get32bit(doh, index));
@@ -404,7 +361,7 @@ static DOHcode store_a(unsigned char *doh, int index, struct dohentry *d)
 static DOHcode store_aaaa(unsigned char *doh, int index, struct dohentry *d)
 {
   /* silently ignore addresses over the limit */
-  if(d->numaddr < MAX_ADDR) {
+  if(d->numaddr < DOH_MAX_ADDR) {
     struct dohaddr *a = &d->addr[d->numaddr];
     struct addr6 *inet6p = &a->ip.v6;
     a->type = DNS_TYPE_AAAA;
@@ -445,9 +402,14 @@ static DOHcode store_cname(unsigned char *doh,
                            unsigned int index,
                            struct dohentry *d)
 {
-  struct cnamestore *c = &d->cname[d->numcname++];
+  struct cnamestore *c;
   unsigned int loop = 128; /* a valid DNS name can never loop this much */
   unsigned char length;
+
+  if(d->numcname == DOH_MAX_CNAME)
+    return DOH_OK; /* skip! */
+
+  c = &d->cname[d->numcname++];
   do {
     if(index >= dohlen)
       return DOH_DNS_OUT_OF_RANGE;
@@ -530,10 +492,10 @@ static DOHcode rdata(unsigned char *doh,
   return DOH_OK;
 }
 
-static DOHcode doh_decode(unsigned char *doh,
-                          size_t dohlen,
-                          DNStype dnstype,
-                          struct dohentry *d)
+UNITTEST DOHcode doh_decode(unsigned char *doh,
+                            size_t dohlen,
+                            DNStype dnstype,
+                            struct dohentry *d)
 {
   unsigned char rcode;
   unsigned short qdcount;
@@ -824,7 +786,7 @@ static const char *type2name(DNStype dnstype)
   return (dnstype == DNS_TYPE_A)?"A":"AAAA";
 }
 
-static void de_cleanup(struct dohentry *d)
+UNITTEST void de_cleanup(struct dohentry *d)
 {
   int i = 0;
   for(i = 0; i < d->numcname; i++) {
diff --git a/lib/doh.h b/lib/doh.h
index e9c017c72..96c1fa7c1 100644
--- a/lib/doh.h
+++ b/lib/doh.h
@@ -41,4 +41,69 @@ CURLcode Curl_doh_is_resolved(struct connectdata *conn,
 int Curl_doh_getsock(struct connectdata *conn, curl_socket_t *socks,
                      int numsocks);
 
+typedef enum {
+  DOH_OK,
+  DOH_DNS_BAD_LABEL,    /* 1 */
+  DOH_DNS_OUT_OF_RANGE, /* 2 */
+  DOH_DNS_LABEL_LOOP,   /* 3 */
+  DOH_TOO_SMALL_BUFFER, /* 4 */
+  DOH_OUT_OF_MEM,       /* 5 */
+  DOH_DNS_RDATA_LEN,    /* 6 */
+  DOH_DNS_MALFORMAT,    /* 7 */
+  DOH_DNS_BAD_RCODE,    /* 8 - no such name */
+  DOH_DNS_UNEXPECTED_TYPE,  /* 9 */
+  DOH_DNS_UNEXPECTED_CLASS, /* 10 */
+  DOH_NO_CONTENT,           /* 11 */
+  DOH_DNS_BAD_ID            /* 12 */
+} DOHcode;
+
+typedef enum {
+  DNS_TYPE_A = 1,
+  DNS_TYPE_NS = 2,
+  DNS_TYPE_CNAME = 5,
+  DNS_TYPE_AAAA = 28
+} DNStype;
+
+#define DOH_MAX_ADDR 24
+#define DOH_MAX_CNAME 4
+
+struct addr6 {
+  unsigned char byte[16];
+};
+
+struct cnamestore {
+  size_t len;       /* length of cname */
+  char *alloc;      /* allocated pointer */
+  size_t allocsize; /* allocated size */
+};
+
+struct dohaddr {
+  int type;
+  union {
+    unsigned int v4;
+    struct addr6 v6;
+  } ip;
+};
+
+struct dohentry {
+  unsigned int ttl;
+  int numaddr;
+  struct dohaddr addr[DOH_MAX_ADDR];
+  int numcname;
+  struct cnamestore cname[DOH_MAX_CNAME];
+};
+
+
+#ifdef DEBUGBUILD
+DOHcode doh_encode(const char *host,
+                   DNStype dnstype,
+                   unsigned char *dnsp, /* buffer */
+                   size_t len,  /* buffer size */
+                   size_t *olen); /* output length */
+DOHcode doh_decode(unsigned char *doh,
+                   size_t dohlen,
+                   DNStype dnstype,
+                   struct dohentry *d);
+void de_cleanup(struct dohentry *d);
+#endif
 #endif