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] [-q tls_engine_conf_file]
[-r] [-s duration]
[-t type] [-v num] [-w] [-x] [-A type] [-B seconds]
[-E oscore_conf_file[,seq_file]] [-G count] [-H hoplimit]
[-K interval] [-L value] [-N] [-O num,text]
[-P scheme://addr[:port]] [-T token] [-U] [-V num]
[-X size]
[-d value]
[[-h match_hint_file] [-k key] [-u user] [-2]]
[[-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, a literal IP address or a Unix domain
name. For Unix domain names, %2F is used as the / separator to differentiate
between the host and patch definitions. For IPv6 address references, angle
brackets are required (c.f. EXAMPLES) to delimit the host portion of the URI.
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 16, 32,
64, 128, 256, 512 or 1024). 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 send from.
-
-q tls_engine_conf_file
-
tls_engine_conf_file contains TLS ENGINE configuration. Only OpenSSL
is currently supported.
See coap-tls-engine-conf(5) for definitions.
-
-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 4, maximum is 8) for general
CoAP logging.
-
-w
-
Append a newline to received data.
-
-x
-
Disable output of PDU data when displaying PDUs.
-
-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).
-
-E oscore_conf_file[,seq_file]
-
oscore_conf_file contains OSCORE configuration. See coap-oscore-conf(5)
for definitions. Optional seq_file (which is created if needed) is used to
save the current transmit sequence number, so on client restart sequence
numbers continue to increase and are not reset to prevent anti-replay
mechanisms being triggered.
-
-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
COAP_BLOCK_TRY_Q_BLOCK 4
COAP_BLOCK_USE_M_Q_BLOCK 8
COAP_BLOCK_NO_PREEMPTIVE_RTAG 16
COAP_BLOCK_STLESS_FETCH 32
-
-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, coaps+tcp, coap+ws, and coaps+ws.
-
-T token
-
Define the initial starting token for the request (up to 24 characters).
-
-U
-
Never include Uri-Host or Uri-Port options.
-
-V num
-
The verbosity level to use (default 3, maximum is 7) for (D)TLS
library logging.
-
-X size
-
Maximum message size to use for TCP based connections (default is 8388864).
Maximum value of 2^32 -1.
OPTIONS - DTLS
(If supported by underlying (D)TLS library)
-
-d count
-
For DTLS, enable use of Connection-ID (RFC9176). If the count is not 0,
then the client will changes its source port every count packets to test
CID.
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).
If the key begins with 0x, then the hex text (two [0-9a-f] per byte) is
converted to binary data.
-
-u user
-
User identity to send for pre-shared key mode (-k option also required).
-
-2
-
Use EC-JPAKE negotiation (if supported).
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 and any intermediate CAs 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
trigger the validation of the server certificate unless overridden by the
-n option.
EXAMPLES
coap-client coap://libcoap.net
Query the resource / from server libcoap.net (using the GET method).
coap-client -m get coap://[::1]/
Query the resource / on localhost using the GET method to get back the
summary information.
coap-client -m get -P coap://upstream-proxy coap://[::1]/
Query the resource / on upstream-proxy using the GET method to get back
the summary information.
coap-client -m get coap://%2Fsome%2Funix%2Fdomain%2Fpath/time
Query the resource /time on server listening on datagram Unix domain
/some/unix/domain/path using the GET method to get back the
current time. The %2F is the hex encoding for / and indicates
which is the host definition separator and the simple / is for the path
definition separator.
coap-client -m get coap://[::1]/.well-known/core
Query on the resource .well-known/core on localhost to get back a list of
the known resources along with their attribute definitions.
echo -n "mode=on" | coap-client -m put \
coap://[2001:db8:c001:f00d:221:2eff:ff00:2704]:5683/actuators/leds?color=r -f-
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.
coap-client -m put coap://[fec0::3]/ck -T 3a -t binary -f to_upload
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)
1.9.4