Command implementations tend to include a substantial amount of common
boilerplate code revolving around the parsing of command-line options
and arguments. This increases the size cost of each command.
Introduce an option-parsing library that abstracts out the common
operations involved in command implementations. This enables the size
of each individual command to be reduced, and also enhances
consistency between commands.
Total size of the library is 704 bytes, to be amortised across all
command implementations.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[netdevice] Allow per-device receive queue processing to be frozen
Several use cases (e.g. the UNDI API and the EFI SNP API) require
access to the raw network device receive queue, and so currently use
manual calls to netdev_poll() on a specific network device in order to
prevent received packets from being processed by the network stack.
As an alternative, provide a flag that allows receive queue processing
to be frozen on a per-device basis. When receive queue processing is
frozen, packets will be enqueued as normal, but will not be
automatically dequeued and passed up the network stack.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[undi] Support underlying UNDI devices that don't support interrupts
Some network cards do not generate interrupts when operated via the
UNDI API. Allow for this by waiting for the ISR to be triggered only
if the PXE stack advertises that it supports interrupts. When the PXE
stack does not advertise interrupt support, we skip the call to
PXENV_UNDI_ISR_IN_START and just poll the device using
PXENV_UNDI_ISR_IN_PROCESS. This matches the observed behaviour of at
least one other PXE NBP (emBoot's winBoot/i), so there is a reasonable
chance of this working.
Originally-implemented-by: Muralidhar Appalla <Muralidhar.Appalla@emulex.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide a "hexhyp" setting type, which functions identically to the
"hex" setting type except that it uses a hyphen instead of a colon as
the byte delimiter.
For example, if ${mac} expands to "52:54:00:12:34:56", then
${mac:hexhyp} will expand to "52-54-00-12-34-56".
Originally-implemented-by: Jarrod Johnson <jarrod.b.johnson@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[list] Fix typographical error from previous commit
Fix typographical error from commit ea631f6 ("[list] Add
list_first_entry()"). The symptom was PXELINUX 3.86 causing a stack
overflow under VMware.
Tested-by: Shao Miller <shao.miller@yrdsb.edu.on.ca>
Signed-off-by: Shao Miller <shao.miller@yrdsb.edu.on.ca>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow fc_ulp_decrement() to guarantee to fc_peer_decrement() that the
peer reference remains valid for the duration of the call, by ensuring
that ulp->peer remains valid while ulp is valid.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[fc] Hold reference to peers and ULPs while calling fc_link_examine()
Allow link examination methods to safely assume that their
self-reference remains valid for the duration of the method call.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[retry] Process at most one timer's expiry in each call to retry_step()
Calling a timer's expiry method may cause arbitrary consequences,
including arbitrary modifications of the list of retry timers.
list_for_each_entry_safe() guards against only deletion of the current
list entry; it provides no protection against other list
modifications. In particular, if a timer's expiry method causes the
subsequent timer in the list to be deleted, then the next loop
iteration will access a timer that may no longer exist.
This is a particularly nasty bug, since absolutely none of the
list-manipulation or reference-counting assertion checks will be
triggered. (The first assertion failure happens on the next iteration
through list_for_each_entry(), showing that the list has become
corrupted but providing no clue as to when this happened.)
Fix by stopping traversal of the list of retry timers as soon as we
hit an expired timer.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[malloc] Avoid immediately clobbering reference count when freeing memory
Rearrange the fields in struct memory_block (without altering
MIN_MEMBLOCK_SIZE) so that the "count" field of a reference-counted
object is left intact when the memory containing the object is freed.
This allows for the possibility of detecting reference-counting errors
such as double-freeing.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[refcnt] Check reference validity on each use of ref_get() and ref_put()
Check that the reference count is valid (i.e. non-negative) on each
call to ref_get() and ref_put(), using an assert() at the point of
use.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[malloc] Use list_for_each_entry_safe() when we may delete a list entry
free_memblock() currently uses list_for_each_entry() to iterate over
the free list, and may delete an entry over which it iterates. While
there is no way that the deleted list entry could be overwritten
before we reference it, this does rely upon list_del() leaving the
"next" pointer intact, which is not guaranteed. Discovered while
tracking down a list-corruption bug (as a result of having modified
list_del() to sanitise the deleted list entry).
Fix by using list_for_each_entry_safe().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
There are several points in the iPXE codebase where
list_for_each_entry() is (ab)used to extract only the first entry from
a list. Add a macro list_first_entry() to make this code easier to
read.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown