132 lines
3.1 KiB
Plaintext
132 lines
3.1 KiB
Plaintext
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DNS Client Application
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======================
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The DNS resolver or DNS client application demonstrates how to use the
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DNS resolver API.
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The DNS API allows to recover IPv4 and IPv6 addresses.
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API Return Codes
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================
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API return codes are documented in the API (see include/iot/dns_client.h).
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Macro | Value | Description
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------------------------------------------------------------------------
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O is always success
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-EINVAL -22 if an invalid parameter was detected
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-EIO -5 network error
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-ENOMEM -12 memory error, perhaps related to network buffers
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Requirements
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============
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'net_tools':
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https://wiki.zephyrproject.org/view/Networking-with-Qemu
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'dnsmasq' application. The dnsmasq version used in this sample is:
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dnsmasq -v
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Dnsmasq version 2.76 Copyright (c) 2000-2016 Simon Kelley
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Building Instructions
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=====================
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Read src/config.h, change the IP addresses according to the LAN
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environment.
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In a terminal window, type make pristine && make to build this sample.
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Usage
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=====
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Run 'loop_socat.sh' and 'loop-slip-tap.sh' as indicated at:
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https://gerrit.zephyrproject.org/r/gitweb?p=net-tools.git;a=blob;f=README
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Set the IPv4 ip address:
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ip addr add 192.0.2.2/24 dev tap0
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Open a terminal window and type:
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dnsmasq -i tap0 -p 5353 -d
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NOTE: some systems may require root privileges to run dnsmaq, use sudo or su.
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If dnsmasq fails to start with an error like this:
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dnsmasq: failed to create listening socket for port 5353: Address already in use
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open a terminal window and type:
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killall -s KILL dnsmasq
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For QEMU, type:
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make qemu
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Sample Output (CONFIG_NET_IPV6=n, CONFIG_NET_IPV4=y)
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====================================================
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To exit from QEMU enter: 'CTRL+a, x'
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[QEMU] CPU: qemu32
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-------------------------------------------
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[run_dns:127] name: not_a_real_domain_name
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rc: -22
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-------------------------------------------
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[run_dns:127] name: zephyrproject.org
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[run_dns:151] 140.211.169.8
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-------------------------------------------
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[run_dns:127] name: www.zephyrproject.org
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[run_dns:151] 140.211.169.8
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-------------------------------------------
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[run_dns:127] name: gerrit.zephyrproject.org
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[run_dns:151] 199.19.213.246
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-------------------------------------------
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[run_dns:127] name: jira.zephyrproject.org
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[run_dns:151] 199.19.213.246
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-------------------------------------------
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[run_dns:127] name: jenkins.zephyrproject.org
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[run_dns:151] 199.19.213.246
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-------------------------------------------
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[run_dns:127] name: linuxfoundation.org
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rc: -5
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-------------------------------------------
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[run_dns:127] name: www.linuxfoundation.org
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[run_dns:151] 140.211.169.4
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-------------------------------------------
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[run_dns:127] name: collabprojects.linuxfoundation.org
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[run_dns:151] 140.211.169.4
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-------------------------------------------
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[run_dns:127] name: events.linuxfoundation.org
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[run_dns:151] 140.211.169.4
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-------------------------------------------
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[run_dns:127] name: training.linuxfoundation.org
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[run_dns:151] 140.211.169.4
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Bye!
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Known Issues
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============
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The above sample contains a rc: -22 (-EINVAL). This is the expected behavior
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for that domain name.
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