NAME¶
coap-client, coap-client-gnutls, coap-client-mbedtls,
coap-client-openssl, coap-client-notls - CoAP Client based on libcoap
SYNOPSIS¶
coap-client [-a addr] [-b [num,]size]
[-e text] [-f file] [-l loss] [-m method]
[-o file] [-p port] [-r] [-s duration]
[-t type] [-v num] [-w] [-A type] [-B
seconds] [-G count] [-H hoplimit] [-K interval]
[-L value] [-N] [-O num,text] [-P
scheme://addr[:port]] [-T token] [-U] [-X size]
[[-h match_hint_file] [-k key] [-u user]] [[-c
certfile] [-j keyfile] [-n] [-C cafile] [-J pkcs11_pin]
[-M rpk_file] [-R trust_casfile]] URI
For coap-client versions that use libcoap compiled for
different (D)TLS libraries, coap-client-notls,
coap-client-gnutls, coap-client-openssl,
coap-client-mbedtls or coap-client-tinydtls may be available.
Otherwise, coap-client uses the default libcoap (D)TLS support.
DESCRIPTION¶
coap-client is a CoAP client to communicate with 6LoWPAN
devices via the protocol CoAP (RFC 7252) using the URI given as argument on
the command line. The URI must have the scheme coap, coap+tcp,
coaps or coaps+tcp. coaps and coaps+tcp are only
supported when coap-client is built with support for secure (D)TLS
communication.
If coaps or coaps+tcp is being used, provided the
CoAP server supports PKI and is configured with a certificate and private
key, the coap-client does not need to have a Pre-Shared Key (-k) or
certificate (-c) configured.
The URI’s host part may be a DNS name or a literal IP
address. Note that, for IPv6 address references, angle brackets are required
(c.f. EXAMPLES).
OPTIONS - GENERAL¶
-a addr
The local address of the interface that has to be used.
Note: Do not use this option if the interface is likely to be
transient - i.e. it is a tunnel interface that may come and go, as this is
likely to cause "No such device" errors on transmission.
-b [num,]size
The block size to be used in GET/PUT/POST requests (value
must be a multiple of 16 not larger than 1024 as libcoap uses a fixed maximum
PDU size of 1400 bytes). If num is present, the request chain will
start at block num. When the server includes a Block2 option in its
response to a GET request, coap-client will automatically retrieve the
subsequent block from the server until there are no more outstanding blocks
for the requested content.
-e text
Include text as payload (use percent-encoding for
non-ASCII characters).
-f file
File to send with PUT/POST (use - for
STDIN).
-l list
Fail to send some datagrams specified by a comma
separated list of numbers or number ranges (debugging only).
-l loss%
Randomly failed to send datagrams with the specified
probability - 100% all datagrams, 0% no datagrams (debugging only).
-m method
The request method for action (get|put|post|delete),
default is get. (Note that the string passed to -m is compared
case-insensitive.)
-o file
A filename to store data retrieved with GET.
-p port
The port to listen on.
-r
Use reliable protocol (TCP or TLS).
-s duration
Subscribe to / observe the resource specified by URI for
the given duration in seconds.
-t type
Content format for given resource for PUT/POST.
type must be either a numeric value reflecting a valid CoAP content
format or a string describing a registered format. The following registered
content format descriptors are supported, with alternative shortcuts given in
parentheses:
text/plain (plain)
application/link-format (link, link-format)
application/xml (xml)
application/octet-stream (binary, octet-stream)
application/exi (exi)
application/json (json)
application/cbor (cbor)
-v num
The verbosity level to use (default 3, maximum is 9).
Above 7, there is increased verbosity in GnuTLS and OpenSSL logging.
-w
Append a newline to received data.
-A type
Accepted media type. type must be either a numeric
value reflecting a valid CoAP content format or a string that specifies a
registered format as described for option -t.
-B seconds
Break operation after waiting given seconds (default is
90).
-G count
Repeat the Request count times with a second delay
between each one. Must have a value between 1 and 255 inclusive. Default is
1.
-H hoplimit
Set the Hop Limit count to hoplimit for proxies. Must
have a value between 1 and 255 inclusive. Default is 16.
-K interval
Send a ping after interval seconds of inactivity. If not
specified (or 0), keep-alive is disabled (default).
-L value
Sum of one or more COAP_BLOCK_* flag values for different
block handling methods. Default is 1 (COAP_BLOCK_USE_LIBCOAP).
COAP_BLOCK_USE_LIBCOAP 1
COAP_BLOCK_SINGLE_BODY 2
-N
Send NON-confirmable message. If option -N is not
specified, a confirmable message will be sent.
-O num,text
Add option num with contents of text to the
request. If the text begins with 0x, then the hex text (two [0-9a-f] per byte)
is converted to binary data.
-P scheme://addr[:port]
Scheme, address and optional port to define how to
connect to a CoAP proxy (automatically adds Proxy-Uri option to request) to
forward the request to. Scheme is one of coap, coaps, coap+tcp and
coaps+tcp.
-T token
Define the initial starting token for the
request.
-U
Never include Uri-Host or Uri-Port options.
-X size
Maximum message size to use for TCP based connections
(default is 8388864). Maximum value of 2^32 -1.
OPTIONS - PSK¶
(If supported by underlying (D)TLS library)
-h match_hint_file
This is a file that contains one or more lines of
received Identity Hints to match to use different user identity and associated
pre-shared key (PSK) (comma separated) instead of the
-k key and
-u
user options. E.g., per line
hint_to_match,use_user,with_key
A line that starts with # is treated as a comment.
Note: -k key and -u user still need to be defined
for the default case in case there is no match.
-k key
Pre-shared key for the specified user identity (-u
option also required).
-u user
User identity to send for pre-shared key mode (-k
option also required).
OPTIONS - PKI¶
(If supported by underlying (D)TLS library)
Note: If any one of certfile, keyfile or
cafile is in PKCS11 URI naming format (pkcs11: prefix), then any
remaining non PKCS11 URI file definitions have to be in DER, not PEM,
format. Otherwise all of certfile, keyfile or cafile
are in PEM format.
-c certfile
PEM file or PKCS11 URI for the certificate. The private
key can also be in the PEM file, or has the same PKCS11 URI. If not, the
private key is defined by -j keyfile.
-j keyfile
PEM file or PKCS11 URI for the private key for the
certificate in -c certfile if the parameter is different from certfile
in -c certfile.
-n
Disable remote peer certificate checking.
-C cafile
PEM file or PKCS11 URI for the CA certificate that was
used to sign the server certfile. Ideally the client certificate should be
signed by the same CA so that mutual authentication can take place. The
contents of cafile are added to the trusted store of root CAs. Using the
-C or -R options will trigger the validation of the server
certificate unless overridden by the -n option.
-J pkcs11_pin
The user pin to unlock access to the PKCS11 token.
-M rpk_file
Raw Public Key (RPK) PEM file or PKCS11 URI that contains
both PUBLIC KEY and PRIVATE KEY or just EC PRIVATE KEY. (GnuTLS and
TinyDTLS(PEM) support only). -C cafile or -R trust_casfile are
not required.
-R trust_casfile
PEM file containing the set of trusted root CAs that are
to be used to validate the server certificate. Alternatively, this can point
to a directory containing a set of CA PEM files. The -C cafile CA does
not have to be in this list and is trusted for the validation. Using -R
trust_casfile disables common CA mutual authentication which can only be
done by using -C cafile. Using the -C or -R options will
will trigger the validation of the server certificate unless overridden by the
-n option.
EXAMPLES¶
•Example
Query the resource / from server coap.me (using the
GET method).
•Example
Query the resource / on localhost using the GET
method to get back the summary defined attributes.
•Example
Query on the resource .well-known/core on localhost to get
back a list of the known resources along with their attribute
definitions.
•Example
Send text mode=on to resource actuators/leds?color=r
on the endpoint with address 2001:db8:c001:f00d:221:2eff:ff00:2704
and port 5683. Note that the port 5683 is the default port and
isn’t actually required in this instance.
•Example
Put the contents of file to_upload with content type
binary (i.e. application/octet-stream) into resource ck on
fec0::3 using a token of 3a via the PUT method.
FILES¶
There are no configuration files.
EXIT STATUS¶
0
Success
1
Failure (syntax or usage error; configuration error;
document processing failure; unexpected error)
AUTHORS¶
The libcoap project
<libcoap-developers@lists.sourceforge.net>
