FIX: adjusting ptr checks

modules/pico_dns_client.c

@@ -596,9 +596,6 @@ static void pico_dns_client_callback(uint16_t ev, struct pico_socket *s)
     }
 
     header = (struct pico_dns_header *)dns_response;
-    domain = (char *)header + sizeof(struct pico_dns_header);
-    qsuffix = (struct pico_dns_question_suffix *)pico_dns_client_seek(domain);
-    /* valid asuffix is determined dynamically later on */
 
     if (pico_dns_client_check_header(header) < 0)
         return;
@@ -607,6 +604,11 @@ static void pico_dns_client_callback(uint16_t ev, struct pico_socket *s)
     if (!q)
         return;
 
+    // FIX: what if the query is not a PTR query?
+    domain = (char *)header + sizeof(struct pico_dns_header);
+    qsuffix = (struct pico_dns_question_suffix *)pico_dns_client_seek(domain);
+    /* valid asuffix is determined dynamically later on */
+
     if (pico_dns_client_check_qsuffix(qsuffix, q) < 0)
         return;
 

modules/pico_dns_sd.c

@@ -73,9 +73,26 @@ pico_dns_sd_kv_vector_strlen( kv_vector *vector )
     /* Iterate over the key-value pairs */
     for (i = 0; i < vector->count; i++) {
         iterator = pico_dns_sd_kv_vector_get(vector, i);
+
+        if (!iterator || !iterator->key) {
+            pico_err = PICO_ERR_EINVAL;
+            return 0;
+        }
+
+        if (len + 1u + strlen(iterator->key) > PICO_DNS_SD_KV_MAXLEN) {
+            pico_err = PICO_ERR_EINVAL;
+            return 0;
+        }
+
         len = (uint16_t) (len + 1u + /* Length byte */
                           strlen(iterator->key) /* Length of the key */);
+
         if (iterator->value) {
+            if (len + 1u + strlen(iterator->value) > PICO_DNS_SD_KV_MAXLEN) {
+                pico_err = PICO_ERR_EINVAL;
+                return 0;
+            }
+
             len = (uint16_t) (len + 1u /* '=' char */ +
                               strlen(iterator->value) /* Length of value */);
         }
@@ -558,7 +575,7 @@ pico_dns_sd_kv_vector_get( kv_vector *vector, uint16_t index )
         return NULL;
 
     /* Return record with conditioned index */
-    if (index < vector->count)
+    if (vector->pairs && (index < vector->count))
         return vector->pairs[index];
 
     return NULL;

modules/pico_dns_sd.h

@@ -44,6 +44,11 @@ typedef struct
 #define PICO_DNS_SD_KV_VECTOR_DECLARE(name) \
     kv_vector (name) = {0}
 
+/* ****************************************************************************
+ *  Maximum length of a key-value pair.
+ * ****************************************************************************/
+#define PICO_DNS_SD_KV_MAXLEN (0xFFFFu)
+
 /* ****************************************************************************
  *  Just calls pico_mdns_init in it's turn to initialise the mDNS-module.
  *  See pico_mdns.h for description.

test/unit/modunit_pico_dns_sd.c

@@ -68,6 +68,54 @@ START_TEST(tc_dns_sd_kv_vector_strlen)
     kv_vector pairs = {
         0
     };
+    uint16_t len;
+    char *long_key = NULL;
+    char *long_value = NULL;
+
+    /* NULL vector */
+    len = pico_dns_sd_kv_vector_strlen(NULL);
+    fail_unless(len == 0, "dns_sd_kv_vector_strlen returned wrong length for a NULL vector!\n");
+
+    /* Empty vector */
+    len = pico_dns_sd_kv_vector_strlen(&pairs);
+    fail_unless(len == 0, "dns_sd_kv_vector_strlen returned wrong length for empty vector!\n");
+
+    /* Wrong vector count with empty vector */
+    pairs.count = 1;
+    len = pico_dns_sd_kv_vector_strlen(&pairs);
+    fail_unless(len == 0, "dns_sd_kv_vector_strlen returned wrong length for a vector with a wrong count!\n");
+    pairs.count = 0;
+
+    /* Wrong vector key */
+    pico_dns_sd_kv_vector_add(&pairs, text, value);
+    pairs.pairs[0]->key = NULL;
+    len = pico_dns_sd_kv_vector_strlen(&pairs);
+    fail_unless(len == 0, "dns_sd_kv_vector_strlen returned wrong length for a vector with a wrong key!\n");
+    pico_dns_sd_kv_vector_erase(&pairs);
+
+    /* Oversize key */
+    long_key = malloc(PICO_DNS_SD_KV_MAXLEN + 1);
+    for (uint16_t i = 0; i < PICO_DNS_SD_KV_MAXLEN; i++) {
+        long_key[i] = '1';
+    }
+    long_key[PICO_DNS_SD_KV_MAXLEN] = '\0';
+    pico_dns_sd_kv_vector_add(&pairs, long_key, value);
+    len = pico_dns_sd_kv_vector_strlen(&pairs);
+    fail_unless(len == 0, "dns_sd_kv_vector_strlen returned wrong length for a vector with an oversize key!\n");
+    pico_dns_sd_kv_vector_erase(&pairs);
+    free(long_key);
+
+    /* Oversize value */
+    long_value = malloc(PICO_DNS_SD_KV_MAXLEN + 1);
+    for (uint16_t i = 0; i < PICO_DNS_SD_KV_MAXLEN; i++) {
+        long_value[i] = '1';
+    }
+    long_value[PICO_DNS_SD_KV_MAXLEN] = '\0';
+    pico_dns_sd_kv_vector_add(&pairs, text, long_value);
+    len = pico_dns_sd_kv_vector_strlen(&pairs);
+    fail_unless(len == 0, "dns_sd_kv_vector_strlen returned wrong length for a vector with an oversize value!\n");
+    pico_dns_sd_kv_vector_erase(&pairs);
+    free(long_value);
 
     pico_dns_sd_kv_vector_add(&pairs, text, value);
     pico_dns_sd_kv_vector_add(&pairs, text2, NULL);
@@ -116,6 +164,7 @@ START_TEST(tc_dns_sd_txt_record_create)
 {
     struct pico_mdns_record *record = NULL;
     struct pico_stack *S = NULL;
+    char *long_value = NULL;
     kv_vector pairs = {
         0
     };
@@ -128,6 +177,35 @@ START_TEST(tc_dns_sd_txt_record_create)
 
     pico_stack_init(&S);
 
+    /* Empty pair */
+    record = pico_dns_sd_txt_record_create(S, "test.local", pairs, 10,
+                                           PICO_MDNS_RECORD_UNIQUE);
+    fail_unless(record == NULL,
+                "pico_dns_sd_txt_record_create shouldn't have a record!\n");
+
+    /* Pair with an empty value */
+    pico_dns_sd_kv_vector_add(&pairs, text, NULL);
+    record = pico_dns_sd_txt_record_create(S, "test.local", pairs, 10,
+                                       PICO_MDNS_RECORD_UNIQUE);
+    fail_unless(record != NULL,
+                "pico_dns_sd_txt_record_create should have a record!\n");
+    pico_dns_sd_kv_vector_erase(&pairs);
+    pico_mdns_record_delete((void **)&record);
+
+    /* Pair with an oversize value */
+    long_value = malloc(PICO_DNS_SD_KV_MAXLEN + 1);
+    for (uint16_t i = 0; i < PICO_DNS_SD_KV_MAXLEN; i++) {
+        long_value[i] = '1';
+    }
+    long_value[PICO_DNS_SD_KV_MAXLEN] = '\0';
+    pico_dns_sd_kv_vector_add(&pairs, text, long_value);
+    record = pico_dns_sd_txt_record_create(S, "test.local", pairs, 10,
+                                       PICO_MDNS_RECORD_UNIQUE);
+    fail_unless(record == NULL,
+                "pico_dns_sd_txt_record_create shouldn't have a record!\n");
+    pico_dns_sd_kv_vector_erase(&pairs);
+    free(long_value);
+
     pico_dns_sd_kv_vector_add(&pairs, text, value);
     pico_dns_sd_kv_vector_add(&pairs, text2, NULL);
     pico_dns_sd_kv_vector_add(&pairs, text3, value3);