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j1939.page: add relevant API calls

pull/66/head
Kurt Van Dijck 2013-11-28 09:56:54 +01:00
parent 7fb5f009fd
commit 234729507e
1 changed files with 47 additions and 0 deletions
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j1939.page
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@ -152,6 +152,10 @@ Most of the subsequent examples will use 2 sockets programs (in 2 terminals).
One will use CAN_J1939 sockets using *testj1939*, One will use CAN_J1939 sockets using *testj1939*,
and the other will use CAN_RAW sockets using cansend+candump. and the other will use CAN_RAW sockets using cansend+candump.
Where I think it's relevant, I added the core API calls that *testj1939* used
because *testj1939* may look too generic to appreciate the degree of control
that the API exposes.
### receive without source address ### receive without source address
Do in terminal 1 Do in terminal 1
@ -177,6 +181,14 @@ In J1939, this means that ECU 0x40 sends directly to ECU 0x41
Since we did not bind to address 0x41, this traffic Since we did not bind to address 0x41, this traffic
is not meant for us and *testj1939* does not receive it. is not meant for us and *testj1939* does not receive it.
*testj1939* used these calls:
sock = ret = socket(PF_CAN, SOCK_DGRAM, CAN_J1939);
ret = bind(sock, (void *)&sockname, sizeof(sockname));
while (1)
ret = recvfrom(sock, dat, sizeof(dat), 0,
(void *)&peername, &peernamelen);
### Use source address ### Use source address
./testj1939 can0:0x80 ./testj1939 can0:0x80
@ -230,6 +242,12 @@ This produces **1BFFFF80#0123456789ABCDEF** on CAN.
will produce exactly the same because **0x80** is the only will produce exactly the same because **0x80** is the only
address currently assigned to **can0:** and is used by default. address currently assigned to **can0:** and is used by default.
*testj1939* used these calls:
sock = ret = socket(PF_CAN, SOCK_DGRAM, CAN_J1939);
ret = bind(sock, (void *)&sockname, sizeof(sockname));
ret = send(sock, dat, todo_send, 0);
### Multiple source addresses on 1 CAN device ### Multiple source addresses on 1 CAN device
ip addr add j1939 0x90 dev can0 ip addr add j1939 0x90 dev can0
@ -279,6 +297,13 @@ Specifing one during bind is therefore sufficient.
emits the very same. emits the very same.
*testj1939* used these calls:
sock = ret = socket(PF_CAN, SOCK_DGRAM, CAN_J1939);
ret = bind(sock, (void *)&sockname, sizeof(sockname));
ret = sendto(sock, dat, todo_send, 0,
(void *)&peername, sizeof(peername));
### Emit different PGNs using the same socket ### Emit different PGNs using the same socket
The PGN is provided in both __bind( *sockname* )__ and The PGN is provided in both __bind( *sockname* )__ and
@ -299,6 +324,13 @@ emits **1B214080#0123456789ABCDEF** .
It makes sometimes sense to omit the PGN in __bind( *sockname* )__ . It makes sometimes sense to omit the PGN in __bind( *sockname* )__ .
*testj1939* used these calls, even for the broadcasted transmission:
sock = ret = socket(PF_CAN, SOCK_DGRAM, CAN_J1939);
ret = bind(sock, (void *)&sockname, sizeof(sockname));
ret = sendto(sock, dat, todo_send, 0,
(void *)&peername, sizeof(peername));
### Larger packets ### Larger packets
J1939 transparently switches to *Transport Protocol* when packets J1939 transparently switches to *Transport Protocol* when packets
@ -313,6 +345,13 @@ emits:
18EBFF80#02EF0123456789AB 18EBFF80#02EF0123456789AB
18EBFF80#03CDEF01234567 18EBFF80#03CDEF01234567
*testj1939* used these same calls:
sock = ret = socket(PF_CAN, SOCK_DGRAM, CAN_J1939);
ret = bind(sock, (void *)&sockname, sizeof(sockname));
ret = sendto(sock, dat, todo_send, 0,
(void *)&peername, sizeof(peername));
The fragments for broadcasted *Transport Protocol* are seperated The fragments for broadcasted *Transport Protocol* are seperated
__50ms__ from each other. __50ms__ from each other.
Destination specific *Transport Protocol* applies flow control Destination specific *Transport Protocol* applies flow control
@ -344,6 +383,14 @@ emits
1801FF80#0123456789ABCDEF 1801FF80#0123456789ABCDEF
0C02FF80#0123456789ABCDEF 0C02FF80#0123456789ABCDEF
*testj1939* used these calls for modified priority:
sock = ret = socket(PF_CAN, SOCK_DGRAM, CAN_J1939);
ret = setsockopt(sock, SOL_CAN_J1939, SO_J1939_SEND_PRIO,
&todo_prio, sizeof(todo_prio));
ret = bind(sock, (void *)&sockname, sizeof(sockname));
ret = send(sock, dat, todo_send, 0);
### using connect ### using connect
### advanced filtering ### advanced filtering