Skip to content

Commit

Permalink
udp: fix again pbuf management (#7132)
Browse files Browse the repository at this point in the history 
* udp: fix again pbuf management
* Process rx buffer size, cache it, because _rx_buf->tot_len is *not* the total size
  • Loading branch information
@d-a-v
d-a-v committed Mar 4, 2020
1 parent b64e8da commit b8e4ca4
Showing 1 changed file with 72 additions and 27 deletions.
99 changes: 72 additions & 27 deletions libraries/ESP8266WiFi/src/include/UdpContext.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,7 @@ class UdpContext
, _rx_buf(0)
, _first_buf_taken(false)
, _rx_buf_offset(0)
, _rx_buf_size(0)
, _refcnt(0)
, _tx_buf_head(0)
, _tx_buf_cur(0)
Expand Down Expand Up @@ -74,6 +75,7 @@ class UdpContext
pbuf_free(_rx_buf);
_rx_buf = 0;
_rx_buf_offset = 0;
_rx_buf_size = 0;
}
}

Expand Down Expand Up @@ -202,12 +204,36 @@ class UdpContext
_on_rx = handler;
}

#ifdef DEBUG_ESP_CORE
// this helper is ready to be used when debugging UDP
void printChain (const pbuf* pb, const char* msg, size_t n) const
{
// printf the pb pbuf chain, bufferred and all at once
char buf[128];
int l = snprintf(buf, sizeof(buf), "UDP: %s %u: ", msg, n);
while (pb)
{
l += snprintf(&buf[l], sizeof(buf) -l, "%p(H=%d,%d<=%d)-",
pb, pb->flags == PBUF_HELPER_FLAG, pb->len, pb->tot_len);
pb = pb->next;
}
l += snprintf(&buf[l], sizeof(buf) - l, "(end)");
DEBUGV("%s\n", buf);
}
#else
void printChain (const pbuf* pb, const char* msg) const
{
(void)pb;
(void)msg;
}
#endif

size_t getSize() const
{
if (!_rx_buf)
return 0;

return _rx_buf->tot_len - _rx_buf_offset;
return _rx_buf_size - _rx_buf_offset;
}

size_t tell() const
Expand All @@ -222,7 +248,7 @@ class UdpContext
}

bool isValidOffset(const size_t pos) const {
return (pos <= _rx_buf->tot_len);
return (pos <= _rx_buf_size);
}

netif* getInputNetif() const
Expand Down Expand Up @@ -262,47 +288,54 @@ class UdpContext
return true;
}

// We have interleaved informations on addresses within received pbuf chain:
// (before ipv6 code we had: (data-pbuf) -> (data-pbuf) -> (data-pbuf) -> ... in the receiving order)
// Now: (address-info-pbuf -> chained-data-pbuf [-> chained-data-pbuf...]) ->
// (chained-address-info-pbuf -> chained-data-pbuf [-> chained...]) -> ...
// _rx_buf is currently adressing a data pbuf,
// in this function it is going to be discarded.

auto deleteme = _rx_buf;

while(_rx_buf->len != _rx_buf->tot_len)
// forward in the chain until next address-info pbuf or end of chain
while(_rx_buf && _rx_buf->flags != PBUF_HELPER_FLAG)
_rx_buf = _rx_buf->next;

_rx_buf = _rx_buf->next;

if (_rx_buf)
{
if (_rx_buf->flags == PBUF_HELPER_FLAG)
{
// we have interleaved informations on addresses within reception pbuf chain:
// before: (data-pbuf) -> (data-pbuf) -> (data-pbuf) -> ... in the receiving order
// now: (address-info-pbuf -> data-pbuf) -> (address-info-pbuf -> data-pbuf) -> ...
assert(_rx_buf->flags == PBUF_HELPER_FLAG);

// so the first rx_buf contains an address helper,
// copy it to "current address"
auto helper = (AddrHelper*)PBUF_ALIGNER(_rx_buf->payload);
_currentAddr = *helper;
// copy address helper to "current address"
auto helper = (AddrHelper*)PBUF_ALIGNER(_rx_buf->payload);
_currentAddr = *helper;

// destroy the helper in the about-to-be-released pbuf
helper->~AddrHelper();
// destroy the helper in the about-to-be-released pbuf
helper->~AddrHelper();

// forward in rx_buf list, next one is effective data
// current (not ref'ed) one will be pbuf_free'd with deleteme
_rx_buf = _rx_buf->next;
}
// forward in rx_buf list, next one is effective data
// current (not ref'ed) one will be pbuf_free'd
// with the 'deleteme' pointer above
_rx_buf = _rx_buf->next;

// this rx_buf is not nullptr by construction,
assert(_rx_buf);
// ref'ing it to prevent release from the below pbuf_free(deleteme)
// (ref counter prevents release and will be decreased by pbuf_free)
pbuf_ref(_rx_buf);
}

// release in chain previous data, and if any:
// current helper, but not start of current data
pbuf_free(deleteme);

_rx_buf_offset = 0;
_rx_buf_size = _processSize(_rx_buf);
return _rx_buf != nullptr;
}

int read()
{
if (!_rx_buf || _rx_buf_offset >= _rx_buf->tot_len)
if (!_rx_buf || _rx_buf_offset >= _rx_buf_size)
return -1;

char c = pbuf_get_at(_rx_buf, _rx_buf_offset);
Expand All @@ -315,9 +348,9 @@ class UdpContext
if (!_rx_buf)
return 0;

size_t max_size = _rx_buf->tot_len - _rx_buf_offset;
size_t max_size = _rx_buf_size - _rx_buf_offset;
size = (size < max_size) ? size : max_size;
DEBUGV(":urd %d, %d, %d\r\n", size, _rx_buf->tot_len, _rx_buf_offset);
DEBUGV(":urd %d, %d, %d\r\n", size, _rx_buf_size, _rx_buf_offset);

void* buf = pbuf_get_contiguous(_rx_buf, dst, size, size, _rx_buf_offset);
if(!buf)
Expand All @@ -333,7 +366,7 @@ class UdpContext

int peek() const
{
if (!_rx_buf || _rx_buf_offset == _rx_buf->tot_len)
if (!_rx_buf || _rx_buf_offset == _rx_buf_size)
return -1;

return pbuf_get_at(_rx_buf, _rx_buf_offset);
Expand All @@ -345,7 +378,7 @@ class UdpContext
if (!_rx_buf)
return;

_consume(_rx_buf->tot_len - _rx_buf_offset);
_consume(_rx_buf_size - _rx_buf_offset);
}

size_t append(const char* data, size_t size)
Expand Down Expand Up @@ -429,6 +462,14 @@ class UdpContext

private:

size_t _processSize (const pbuf* pb)
{
size_t ret = 0;
for (; pb && pb->flags != PBUF_HELPER_FLAG; pb = pb->next)
ret += pb->len;
return ret;
}

void _reserve(size_t size)
{
const size_t pbuf_unit_size = 128;
Expand Down Expand Up @@ -466,8 +507,8 @@ class UdpContext
void _consume(size_t size)
{
_rx_buf_offset += size;
if (_rx_buf_offset > _rx_buf->tot_len) {
_rx_buf_offset = _rx_buf->tot_len;
if (_rx_buf_offset > _rx_buf_size) {
_rx_buf_offset = _rx_buf_size;
}
}

Expand All @@ -476,6 +517,7 @@ class UdpContext
{
(void) upcb;
// check receive pbuf chain depth
// optimization path: cache the pbuf chain length
{
pbuf* p;
int count = 0;
Expand All @@ -488,6 +530,7 @@ class UdpContext
return;
}
}

#if LWIP_VERSION_MAJOR == 1
#define TEMPDSTADDR (&current_iphdr_dest)
#define TEMPINPUTNETIF (current_netif)
Expand Down Expand Up @@ -541,6 +584,7 @@ class UdpContext
_first_buf_taken = false;
_rx_buf = pb;
_rx_buf_offset = 0;
_rx_buf_size = pb->tot_len;
}

if (_on_rx) {
Expand Down Expand Up @@ -648,6 +692,7 @@ class UdpContext
pbuf* _rx_buf;
bool _first_buf_taken;
size_t _rx_buf_offset;
size_t _rx_buf_size;
int _refcnt;
pbuf* _tx_buf_head;
pbuf* _tx_buf_cur;
Expand Down

0 comments on commit b8e4ca4

Please sign in to comment.