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net: lwm2m: add multi fragment support to LwM2M library

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The existing LwM2M framework expected contiguous buffers and this
was the reason for the 384 byte buffer sizes.  This was previously
a limitation of the ZoAP API. The new CoAP API doesn't have this
limitation and the LwM2M library has already been migrated to use
it.

Let's finish the process by replacing any contiguous buffer handling
with the correct net_pkt APIs to parse across multiple fragments.

Signed-off-by: Michael Scott <michael.scott@linaro.org>
This commit is contained in:
Michael Scott 2017-10-19 16:27:32 -07:00 • committed by Jukka Rissanen
commit b37a005d68
9 changed files with 727 additions and 799 deletions
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221
subsys/net/lib/lwm2m/lwm2m_engine.c
View file

@ -1863,11 +1863,14 @@ int lwm2m_write_handler(struct lwm2m_engine_obj_inst *obj_inst,
data_len = res->data_len;
/* setup data_ptr/data_len for OPAQUE when it has none setup */
/* FIXME: */
#if 0
if (obj_field->data_type == LWM2M_RES_TYPE_OPAQUE &&
data_ptr == NULL && data_len == 0) {
data_ptr = in->inbuf;
data_len = in->insize;
}
#endif
/* allow user to override data elements via callback */
if (res->pre_write_cb) {
@ -1878,10 +1881,13 @@ int lwm2m_write_handler(struct lwm2m_engine_obj_inst *obj_inst,
switch (obj_field->data_type) {
/* do nothing for OPAQUE (probably has a callback) */
/* FIXME: */
#if 0
case LWM2M_RES_TYPE_OPAQUE:
data_ptr = in->inbuf;
len = in->insize;
break;
#endif
case LWM2M_RES_TYPE_STRING:
engine_get_string(in, (u8_t *)data_ptr, data_len);
@ -2040,113 +2046,47 @@ static int lwm2m_delete_handler(struct lwm2m_engine_obj *obj,
context->path->obj_inst_id);
}
static int get_coap_packet_len(struct net_pkt *pkt)
{
struct net_buf *frag;
u16_t offset;
u16_t len;
frag = net_frag_read_be16(pkt->frags,
net_pkt_ip_hdr_len(pkt) +
net_pkt_ipv6_ext_len(pkt) +
4, &offset, &len);
if (!frag && offset == 0xffff) {
return -1;
}
return len - NET_UDPH_LEN;
}
#define COAP_MARKER 0xFF
/* TODO: Remove in favor of using net_buf pointer to payload */
u8_t *coap_packet_get_payload_ptr(struct coap_packet *cpkt, u16_t *len,
bool start_marker)
{
u8_t *appdata = cpkt->pkt->frags->data;
u16_t appdatalen = cpkt->pkt->frags->len;
u8_t *start = NULL; /* Start of the payload */
s32_t payload_size = 0;
if (!cpkt || !len) {
return NULL;
}
*len = 0;
if (start_marker) {
if (appdatalen + 1 >= net_buf_tailroom(cpkt->pkt->frags)) {
return NULL;
}
appdata[appdatalen] = COAP_MARKER;
cpkt->pkt->frags->len += 1;
start = appdata + appdatalen + 1;
payload_size = appdata + net_buf_tailroom(cpkt->pkt->frags) - start;
} else {
payload_size = get_coap_packet_len(cpkt->pkt);
payload_size -= (cpkt->hdr_len + cpkt->opt_len);
if (payload_size > 0) {
start = appdata;
start += net_pkt_ip_hdr_len(cpkt->pkt);
start += net_pkt_ipv6_ext_len(cpkt->pkt);
start += NET_UDPH_LEN;
start += cpkt->hdr_len + cpkt->opt_len;
} else {
payload_size = 0;
}
}
*len = payload_size;
return start;
}
/* TODO: Remove in favor of using net_pkt APIs to add data to payload */
int coap_packet_set_used(struct coap_packet *cpkt, u16_t len)
{
if ((cpkt->pkt->frags->len + len) >
net_buf_tailroom(cpkt->pkt->frags)) {
return -ENOMEM;
}
cpkt->pkt->frags->len += len;
return 0;
}
/*
* CoAP API needs to create the net_pkt buffer in the correct order.
* This function performs last minute verification that outbuf is initialized.
*/
static void outbuf_init_check(struct lwm2m_output_context *out)
{
if (!out->outbuf) {
out->outbuf = coap_packet_get_payload_ptr(out->out_cpkt,
&out->outsize, true);
}
}
#define MATCH_NONE 0
#define MATCH_ALL 1
#define MATCH_SINGLE 2
static int do_read_op(struct lwm2m_engine_obj *obj,
struct lwm2m_engine_context *context)
struct lwm2m_engine_context *context,
u16_t content_format)
{
struct lwm2m_output_context *out = context->out;
struct lwm2m_obj_path *path = context->path;
struct lwm2m_engine_obj_inst *obj_inst;
int ret = 0, pos = 0, index, match_type;
int ret = 0, index, match_type;
u8_t num_read = 0;
u8_t initialized;
struct lwm2m_engine_res_inst *res;
struct lwm2m_engine_obj_field *obj_field;
u16_t temp_res_id;
u16_t temp_res_id, temp_len;
obj_inst = get_engine_obj_inst(path->obj_id, path->obj_inst_id);
if (!obj_inst) {
return -ENOENT;
}
/* set output content-format */
ret = coap_append_option_int(out->out_cpkt, COAP_OPTION_CONTENT_FORMAT,
content_format);
if (ret < 0) {
SYS_LOG_ERR("Error setting response content-format: %d", ret);
return ret;
}
ret = coap_packet_append_payload_marker(out->out_cpkt);
if (ret < 0) {
SYS_LOG_ERR("Error appending payload marker: %d", ret);
return ret;
}
out->frag = coap_packet_get_payload(out->out_cpkt, &out->offset,
&temp_len);
out->offset++;
while (obj_inst) {
if (!obj_inst->resources || obj_inst->resource_count == 0) {
continue;
@ -2193,9 +2133,8 @@ static int do_read_op(struct lwm2m_engine_obj *obj,
LWM2M_PERM_R) != LWM2M_PERM_R) {
ret = -EPERM;
} else {
/* outbuf init / formatter startup if needed */
/* formatter startup if needed */
if (!initialized) {
outbuf_init_check(out);
engine_put_begin(out, path);
initialized = 1;
}
@ -2208,7 +2147,6 @@ static int do_read_op(struct lwm2m_engine_obj *obj,
SYS_LOG_ERR("READ OP failed: %d", ret);
} else {
num_read += 1;
pos = out->outlen;
}
}
@ -2227,7 +2165,6 @@ static int do_read_op(struct lwm2m_engine_obj *obj,
/* if we wrote anything, finish formatting */
if (initialized) {
engine_put_end(out, path);
pos = out->outlen;
}
/* advance to the next object instance */
@ -2240,31 +2177,41 @@ static int do_read_op(struct lwm2m_engine_obj *obj,
return -ENOENT;
}
out->outlen = pos;
return ret;
}
static int do_discover_op(struct lwm2m_engine_context *context)
{
static char disc_buf[24];
struct lwm2m_output_context *out = context->out;
struct lwm2m_engine_obj_inst *obj_inst;
int i = 0, ret;
u16_t temp_len;
/* set output content-format */
ret = coap_append_option_int(out->out_cpkt,
COAP_OPTION_CONTENT_FORMAT,
LWM2M_FORMAT_APP_LINK_FORMAT);
COAP_OPTION_CONTENT_FORMAT,
LWM2M_FORMAT_APP_LINK_FORMAT);
if (ret < 0) {
SYS_LOG_ERR("Error setting response content-format: %d", ret);
return ret;
}
ret = coap_packet_append_payload_marker(out->out_cpkt);
if (ret < 0) {
return ret;
}
/* init the outbuffer */
out->outbuf = coap_packet_get_payload_ptr(out->out_cpkt,
&out->outsize, true);
out->frag = coap_packet_get_payload(out->out_cpkt, &out->offset,
&temp_len);
out->offset++;
/* </.well-known/core>,**;ct=40 */
memcpy(out->outbuf, DISCOVER_PREFACE, strlen(DISCOVER_PREFACE));
out->outlen += strlen(DISCOVER_PREFACE);
if (!net_pkt_append_all(out->out_cpkt->pkt,
strlen(DISCOVER_PREFACE), DISCOVER_PREFACE,
BUF_ALLOC_TIMEOUT)) {
return -ENOMEM;
}
SYS_SLIST_FOR_EACH_CONTAINER(&engine_obj_inst_list, obj_inst, node) {
/* TODO: support bootstrap discover
@ -2274,23 +2221,29 @@ static int do_discover_op(struct lwm2m_engine_context *context)
continue;
}
out->outlen += snprintk(&out->outbuf[out->outlen],
out->outsize - out->outlen,
",</%u/%u>",
obj_inst->obj->obj_id,
obj_inst->obj_inst_id);
snprintk(disc_buf, sizeof(disc_buf), ",</%u/%u>",
obj_inst->obj->obj_id, obj_inst->obj_inst_id);
if (!net_pkt_append_all(out->out_cpkt->pkt,
strlen(disc_buf), disc_buf,
BUF_ALLOC_TIMEOUT)) {
return -ENOMEM;
}
for (i = 0; i < obj_inst->resource_count; i++) {
out->outlen += snprintk(&out->outbuf[out->outlen],
out->outsize - out->outlen,
",</%u/%u/%u>",
obj_inst->obj->obj_id,
obj_inst->obj_inst_id,
obj_inst->resources[i].res_id);
snprintk(disc_buf, sizeof(disc_buf),
",</%u/%u/%u>",
obj_inst->obj->obj_id,
obj_inst->obj_inst_id,
obj_inst->resources[i].res_id);
if (!net_pkt_append_all(out->out_cpkt->pkt,
strlen(disc_buf), disc_buf,
BUF_ALLOC_TIMEOUT)) {
return -ENOMEM;
}
}
}
out->outbuf[out->outlen] = '\0';
return 0;
}
@ -2502,8 +2455,9 @@ static int handle_request(struct coap_packet *request,
msg->token = token;
}
in.inpos = 0;
in.inbuf = coap_packet_get_payload_ptr(in.in_cpkt, &in.insize, false);
/* setup incoming data */
in.frag = coap_packet_get_payload(in.in_cpkt, &in.offset,
&in.payload_len);
/* Check for block transfer */
r = get_option_int(in.in_cpkt, COAP_OPTION_BLOCK1);
@ -2511,7 +2465,7 @@ static int handle_request(struct coap_packet *request,
/* RFC7252: 4.6. Message Size */
block_size = GET_BLOCK_SIZE(r);
if (GET_MORE(r) &&
coap_block_size_to_bytes(block_size) > in.insize) {
coap_block_size_to_bytes(block_size) > in.payload_len) {
SYS_LOG_DBG("Trailing payload is discarded!");
r = -EFBIG;
goto error;
@ -2578,17 +2532,7 @@ static int handle_request(struct coap_packet *request,
}
}
/* set output content-format */
r = coap_append_option_int(out.out_cpkt,
COAP_OPTION_CONTENT_FORMAT,
accept);
if (r < 0) {
SYS_LOG_ERR("Error setting response content-format: %d",
r);
goto error;
}
r = do_read_op(obj, &context);
r = do_read_op(obj, &context, accept);
break;
case LWM2M_OP_DISCOVER:
@ -2627,7 +2571,7 @@ static int handle_request(struct coap_packet *request,
/* More to come, ack with correspond block # */
r = coap_append_block1_option(out.out_cpkt,
&block_ctx->ctx);
if (r) {
if (r < 0) {
/* report as internal server error */
SYS_LOG_ERR("Fail adding block1 option: %d", r);
r = -EINVAL;
@ -2636,13 +2580,6 @@ static int handle_request(struct coap_packet *request,
}
}
if (out.outlen > 0) {
SYS_LOG_DBG("replying with %u bytes", out.outlen);
coap_packet_set_used(out.out_cpkt, out.outlen);
} else {
SYS_LOG_DBG("no data in reply");
}
return 0;
error:
@ -2970,22 +2907,8 @@ static int generate_notify_message(struct observe_node *obs,
/* set the output writer */
select_writer(&out, obs->format);
/* set response content-format */
ret = coap_append_option_int(&msg->cpkt, COAP_OPTION_CONTENT_FORMAT,
obs->format);
ret = do_read_op(obj_inst->obj, &context, obs->format);
if (ret < 0) {
SYS_LOG_ERR("error setting content-format (err:%d)", ret);
goto cleanup;
}
ret = do_read_op(obj_inst->obj, &context);
if (ret == 0) {
if (out.outlen > 0) {
coap_packet_set_used(out.out_cpkt, out.outlen);
} else {
SYS_LOG_DBG("no data in reply");
}
} else {
SYS_LOG_ERR("error in multi-format read (err:%d)", ret);
goto cleanup;
}