dns: FIX add README_API file and improve sample code
README_API file is added in this patch.
Inline code documentation is improved. More test domains are added.
The README file is also updated to reflect these changes.
Change-Id: Ie670a6559611c6a8d216470e245dbea48369696f
Signed-off-by: Flavio Santes <flavio.santes@intel.com>
diff --git a/samples/net/dns_client/README b/samples/net/dns_client/README
index f3c04e2..bb56936 100644
--- a/samples/net/dns_client/README
+++ b/samples/net/dns_client/README
@@ -1,5 +1,6 @@
DNS Client Application
+
Requirements
------------
@@ -11,8 +12,9 @@
* dnsmasq application. The dnsmasq version used in this sample is:
-dnsmasq -v
-Dnsmasq version 2.75 Copyright (c) 2000-2015 Simon Kelley
+ dnsmasq -v
+ Dnsmasq version 2.75 Copyright (c) 2000-2015 Simon Kelley
+
Building instructions
---------------------
@@ -34,69 +36,104 @@
* Open a terminal window and type:
-dnsmasq -d
+ dnsmasq -d
* Connect the USB-UART cable to the Galileo. Open a terminal and run:
- screen /dev/ttyUSB0 115200
+ screen /dev/ttyUSB0 115200
* Connect Galileo to the LAN, Turn on the board.
* The screen terminal window will show:
- WARNING: no console will be available to OS
- error: no suitable video mode found.
-
-----------------------------------------
Domain name: not_a_real_domain_name
- [fiber:82] DNS Create Query: 0, ID: 1
- [fiber:85] TX: 0
- [fiber:88] RX: -5
+ [fiber:89] DNS Query: OK, ID: 0
+ [fiber:92] TX: OK
+ [fiber:97] RX: OK
+ [fiber:102] DNS Response: ERROR <- :)
-----------------------------------------
- Domain name: oops!
- [fiber:82] DNS Create Query: 0, ID: 2
- [fiber:85] TX: 0
- [fiber:88] RX: 0
- [fiber:95] DNS response: 2
-
- -----------------------------------------
- Domain name: zephyrproject.org
- [fiber:82] DNS Create Query: 0, ID: 3
- [fiber:85] TX: 0
- [fiber:88] RX: 0
+ Domain name: linuxfoundation.org
+ [fiber:89] DNS Query: OK, ID: 1
+ [fiber:92] TX: OK
+ [fiber:97] RX: OK
****** DNS ANSWER: 0 ******
- Response: IP address Size: 4: 140 211 169 8
- [fiber:95] DNS response: 0
+ Response: IP address Size: 4: 140 211 169 4
+
+ [fiber:102] DNS Response: OK
-----------------------------------------
- Domain name: www.google.com
- [fiber:82] DNS Create Query: 0, ID: 4
- [fiber:85] TX: 0
- [fiber:88] RX: 0
+ Domain name: www.linuxfoundation.org
+ [fiber:89] DNS Query: OK, ID: 2
+ [fiber:92] TX: OK
+ [fiber:97] RX: OK
****** DNS ANSWER: 0 ******
- Response: IP address Size: 4: 216 58 192 4
- [fiber:95] DNS response: 0
+ Response: IP address Size: 4: 140 211 169 4
+
+ [fiber:102] DNS Response: OK
-----------------------------------------
- Domain name: mail.yahoo.com
- [fiber:82] DNS Create Query: 0, ID: 5
- [fiber:85] TX: 0
- [fiber:88] RX: 0
+ Domain name: gnu.org
+ [fiber:89] DNS Query: OK, ID: 3
+ [fiber:92] TX: OK
+ [fiber:97] RX: OK
****** DNS ANSWER: 0 ******
- Response: CNAME NO IP address Size: 8: 5 108 111 103 105 110 192 17
- CNAME: login.yahoo.com
+ Response: IP address Size: 4: 208 118 235 148
+
+ [fiber:102] DNS Response: OK
+
+ -----------------------------------------
+ Domain name: www.gnu.org
+ [fiber:89] DNS Query: OK, ID: 4
+ [fiber:92] TX: OK
+ [fiber:97] RX: OK
+
+ ****** DNS ANSWER: 0 ******
+ Response: CNAME NO IP address
+ CNAME: wildebeest.gnu.org
+
****** DNS ANSWER: 1 ******
- Response: CNAME NO IP address Size: 35: 9 102 111 45 100 115 45 97 116 115 6 109 101 109 98 101 114 3 103 48 50 8 121 97 104 111 111 100 110 115 3 110 101 116 0
- CNAME: fo-ds-ats.member.g02.yahoodns.net
+ Response: IP address Size: 4: 208 118 235 148
- ****** DNS ANSWER: 2 ******
- Response: IP address Size: 4: 98 136 189 41
- [fiber:95] DNS response: 0
+ [fiber:102] DNS Response: OK
-----------------------------------------
- Bye!
+ Domain name: npr.org
+ [fiber:89] DNS Query: OK, ID: 5
+ [fiber:92] TX: OK
+ [fiber:97] RX: OK
+
+ ****** DNS ANSWER: 0 ******
+ Response: IP address Size: 4: 216 35 221 76
+
+ [fiber:102] DNS Response: OK
+
+ -----------------------------------------
+ Domain name: www.npr.org
+ [fiber:89] DNS Query: OK, ID: 6
+ [fiber:92] TX: OK
+ [fiber:97] RX: OK
+
+ ****** DNS ANSWER: 0 ******
+ Response: CNAME NO IP address
+ CNAME: www-cdn.npr.org.edgesuite.net
+
+
+ ****** DNS ANSWER: 1 ******
+ Response: CNAME NO IP address
+ CNAME: a1723.g.akamai.net
+
+
+ ****** DNS ANSWER: 2 ******
+ Response: IP address Size: 4: 63 80 4 192
+
+
+ ****** DNS ANSWER: 3 ******
+ Response: IP address Size: 4: 63 80 4 161
+
+ [fiber:102] DNS Response: OK
diff --git a/samples/net/dns_client/README_API b/samples/net/dns_client/README_API
new file mode 100644
index 0000000..b02812e
--- /dev/null
+++ b/samples/net/dns_client/README_API
@@ -0,0 +1,23 @@
+DNS Client API
+
+-----------------------------------------------------------------------
+ THIS API IS STILL WORK IN PROGRESS
+-----------------------------------------------------------------------
+
+The DNS Client API for Zephyr is a collection of C files:
+
+ - dns_pack.h, dns_pack.c:
+ RFC 1035 serialization and deserialization functions
+
+ - dns_utils.h. dns_utils.c:
+ Helper functions
+
+TODO
+
+ - Implement high-level functions to handle the server's response
+ - Remove:
+ * dns_query in src/main.c and handle the Transaction
+ Identifier internally.
+ * dns_response in src/main.c once high-level functions are
+ available.
+
diff --git a/samples/net/dns_client/src/main.c b/samples/net/dns_client/src/main.c
index b7e14f6..e69cf43 100644
--- a/samples/net/dns_client/src/main.c
+++ b/samples/net/dns_client/src/main.c
@@ -27,19 +27,26 @@
uint8_t stack[STACK_SIZE];
#define BUF_SIZE 1024
-
uint8_t tx_raw_buf[BUF_SIZE];
uint8_t rx_raw_buf[BUF_SIZE];
-#define SLEEP_TIME 10
+#define SLEEP_TIME 50
-char *domains[] = {"not_a_real_domain_name", "oops!",
- "zephyrproject.org", "www.google.com",
- "mail.yahoo.com", NULL};
+#define RC_STR(rc) (rc == 0 ? "OK" : "ERROR")
+char *domains[] = {"not_a_real_domain_name",
+ "linuxfoundation.org", "www.linuxfoundation.org",
+ "gnu.org", "www.gnu.org",
+ "npr.org", "www.npr.org",
+ "wikipedia.org", "www.wikipedia.org",
+ "zephyrproject.org", "www.zephyrproject.org",
+ NULL};
+
+/* this function creates the DNS query */
int dns_query(struct app_buf_t *buf, char *str, uint16_t id,
enum dns_rr_type qtype);
+/* this function parses the DNS server response */
int dns_response(struct app_buf_t *_buf, int *response_type, int src_id);
void fiber(void)
@@ -50,6 +57,9 @@
struct app_buf_t rx_buf = APP_BUF_INIT(rx_raw_buf,
sizeof(rx_raw_buf), 0);
+ /* If the network is a bit slow, increase rx_timeout and
+ * tx_retry_timeout in struct netz_ctx_t
+ */
struct netz_ctx_t netz_ctx = NETZ_CTX_INIT;
int response_type;
@@ -64,41 +74,39 @@
counter = 0;
do {
- fiber_sleep(300);
-
printf("\n-----------------------------------------\n");
name = domains[counter];
if (name == NULL) {
counter = 0;
- break;
+ continue;
}
- counter += 1;
printf("Domain name: %s\n", name);
rc = dns_query(&tx_buf, name, counter, DNS_RR_TYPE_A);
- printf("[%s:%d] DNS Create Query: %d, ID: %d\n",
- __func__, __LINE__, rc, counter);
+ printf("[%s:%d] DNS Query: %s, ID: %d\n",
+ __func__, __LINE__, RC_STR(rc), counter);
rc = netz_tx(&netz_ctx, &tx_buf);
- printf("[%s:%d] TX: %d\n", __func__, __LINE__, rc);
+ printf("[%s:%d] TX: %s\n", __func__, __LINE__, RC_STR(rc));
+
+ fiber_sleep(SLEEP_TIME);
rc = netz_rx(&netz_ctx, &rx_buf);
- printf("[%s:%d] RX: %d\n", __func__, __LINE__, rc);
+ printf("[%s:%d] RX: %s\n", __func__, __LINE__, RC_STR(rc));
- if (rc != 0) {
- continue;
+ if (rc == 0) {
+ rc = dns_response(&rx_buf, &response_type, counter);
+ printf("[%s:%d] DNS Response: %s %s\n",
+ __func__, __LINE__, RC_STR(rc),
+ (rc != 0 && counter == 0 ? "<- :)" : ""));
}
- rc = dns_response(&rx_buf, &response_type, counter);
- printf("[%s:%d] DNS response: %d\n", __func__, __LINE__, rc);
-
-
+ counter += 1;
+ fiber_sleep(SLEEP_TIME);
} while (1);
- printf("Bye!\n");
-
}
void main(void)
@@ -109,13 +117,18 @@
0, 0, 7, 0);
}
-
+/* Next versions must handle the transaction id internally */
int dns_query(struct app_buf_t *buf, char *str, uint16_t id,
enum dns_rr_type qtype)
{
return dns_msg_pack_query(buf, str, id, qtype);
}
+/* See dns_unpack_answer, and also see:
+ * https://tools.ietf.org/html/rfc1035#section-4.1.2
+ */
+#define DNS_QUERY_POS 0x0c
+
int dns_response(struct app_buf_t *_buf, int *response_type, int src_id)
{
struct dns_msg_t dns_msg = DNS_MSG_INIT(_buf->buf, _buf->size);
@@ -125,7 +138,7 @@
rc = dns_unpack_response_header(&dns_msg, src_id);
if (rc != 0) {
- return rc;
+ return -EINVAL;
}
if (dns_header_qdcount(dns_msg.msg) != 1) {
@@ -134,20 +147,18 @@
rc = dns_unpack_response_query(&dns_msg);
if (rc != 0) {
- return rc;
+ return -EINVAL;
}
i = 0;
- /* the first dname is at 0x0c bytes */
- ptr = 0x0c;
+ ptr = DNS_QUERY_POS;
while (i < dns_header_ancount(dns_msg.msg)) {
printf("\n****** DNS ANSWER: %d ******\n", i);
rc = dns_unpack_answer(&dns_msg, ptr);
if (rc != 0) {
- printf("[%s:%d]\n", __func__, __LINE__);
- return rc;
+ return -EINVAL;
}
switch (dns_msg.response_type) {
@@ -156,18 +167,16 @@
dns_msg.response_length);
print_buf(dns_msg.msg + dns_msg.response_position,
dns_msg.response_length);
+ printf("\n");
break;
case DNS_RESPONSE_CNAME_NO_IP:
- printf("Response: CNAME NO IP address\t\tSize: %d:\t",
- dns_msg.response_length);
- print_buf(dns_msg.msg + dns_msg.response_position,
- dns_msg.response_length);
- printf("CNAME: ");
+ printf("Response: CNAME NO IP address");
+ printf("\nCNAME: ");
dns_print_readable_msg_label(dns_msg.response_position,
dns_msg.msg,
dns_msg.msg_size);
-
+ printf("\n");
ptr = dns_msg.response_position;
break;
@@ -179,9 +188,7 @@
}
dns_msg.answer_offset = dns_msg.answer_offset + 12
- + dns_msg.response_length;
-
-
+ + dns_msg.response_length;
++i;
}
