Currently the string functions grub_strtol(), grub_strtoul(), and
grub_strtoull() don't declare the "end" pointer in such a way as to
require the pointer itself or the character array to be immutable to the
implementation, nor does the C standard do so in its similar functions,
though it does require us not to change any of it.
The typical declarations of these functions follow this pattern:
long
strtol(const char * restrict nptr, char ** restrict endptr, int base);
Much of the reason for this is historic, and a discussion of that
follows below, after the explanation of this change. (GRUB currently
does not include the "restrict" qualifiers, and we name the arguments a
bit differently.)
The implementation is semantically required to treat the character array
as immutable, but such accidental modifications aren't stopped by the
compiler, and the semantics for both the callers and the implementation
of these functions are sometimes also helped by adding that requirement.
This patch changes these declarations to follow this pattern instead:
long
strtol(const char * restrict nptr,
const char ** const restrict endptr,
int base);
This means that if any modification to these functions accidentally
introduces either an errant modification to the underlying character
array, or an accidental assignment to endptr rather than *endptr, the
compiler should generate an error. (The two uses of "restrict" in this
case basically mean strtol() isn't allowed to modify the character array
by going through *endptr, and endptr isn't allowed to point inside the
array.)
It also means the typical use case changes to:
char *s = ...;
const char *end;
long l;
l = strtol(s, &end, 10);
Or even:
const char *p = str;
while (p && *p) {
long l = strtol(p, &p, 10);
...
}
This fixes 26 places where we discard our attempts at treating the data
safely by doing:
const char *p = str;
long l;
l = strtol(p, (char **)&ptr, 10);
It also adds 5 places where we do:
char *p = str;
while (p && *p) {
long l = strtol(p, (const char ** const)&p, 10);
...
/* more calls that need p not to be pointer-to-const */
}
While moderately distasteful, this is a better problem to have.
With one minor exception, I have tested that all of this compiles
without relevant warnings or errors, and that /much/ of it behaves
correctly, with gcc 9 using 'gcc -W -Wall -Wextra'. The one exception
is the changes in grub-core/osdep/aros/hostdisk.c , which I have no idea
how to build.
Because the C standard defined type-qualifiers in a way that can be
confusing, in the past there's been a slow but fairly regular stream of
churn within our patches, which add and remove the const qualifier in many
of the users of these functions. This change should help avoid that in
the future, and in order to help ensure this, I've added an explanation
in misc.h so that when someone does get a compiler warning about a type
error, they have the fix at hand.
The reason we don't have "const" in these calls in the standard is
purely anachronistic: C78 (de facto) did not have type qualifiers in the
syntax, and the "const" type qualifier was added for C89 (I think; it
may have been later). strtol() appears to date from 4.3BSD in 1986,
which means it could not be added to those functions in the standard
without breaking compatibility, which is usually avoided.
The syntax chosen for type qualifiers is what has led to the churn
regarding usage of const, and is especially confusing on string
functions due to the lack of a string type. Quoting from C99, the
syntax is:
declarator:
pointer[opt] direct-declarator
direct-declarator:
identifier
( declarator )
direct-declarator [ type-qualifier-list[opt] assignment-expression[opt] ]
...
direct-declarator [ type-qualifier-list[opt] * ]
...
pointer:
* type-qualifier-list[opt]
* type-qualifier-list[opt] pointer
type-qualifier-list:
type-qualifier
type-qualifier-list type-qualifier
...
type-qualifier:
const
restrict
volatile
So the examples go like:
const char foo; // immutable object
const char *foo; // mutable pointer to object
char * const foo; // immutable pointer to mutable object
const char * const foo; // immutable pointer to immutable object
const char const * const foo; // XXX extra const keyword in the middle
const char * const * const foo; // immutable pointer to immutable
// pointer to immutable object
const char ** const foo; // immutable pointer to mutable pointer
// to immutable object
Making const left-associative for * and right-associative for everything
else may not have been the best choice ever, but here we are, and the
inevitable result is people using trying to use const (as they should!),
putting it at the wrong place, fighting with the compiler for a bit, and
then either removing it or typecasting something in a bad way. I won't
go into describing restrict, but its syntax has exactly the same issue
as with const.
Anyway, the last example above actually represents the *behavior* that's
required of strtol()-like functions, so that's our choice for the "end"
pointer.
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This patch implements a search for a specific configuration when the config
file is on a remoteserver. It uses the following order:
1) DHCP client UUID option.
2) MAC address (in lower case hexadecimal with dash separators);
3) IP (in upper case hexadecimal) or IPv6;
4) The original grub.cfg file.
This procedure is similar to what is used by pxelinux and yaboot:
http://www.syslinux.org/wiki/index.php/PXELINUX#config
It is enabled by default but can be disabled by setting the environment
variable "feature_net_search_cfg" to "n" in an embedded configuration.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=873406
Signed-off-by: Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
If we open new connection, we need to reset stall indication, otherwise
nothing will ever be polled (low level code rely on this field being
zero when establishing connection).
ipv6 routing in grub2 is broken, we cannot talk to anything outside our local
network or anything that doesn't route in our global namespace. This patch
fixes this by doing a couple of things
1) Read the router information off of the router advertisement. If we have a
router lifetime we need to take the source address and create a route from it.
2) Changes the routing stuff slightly to allow you to specify a gateway _and_ an
interface. Since the router advertisements come in on the link local address we
need to associate it with the global address on the card. So when we are
processing the router advertisement, either use the SLAAC interface we create
and add the route to that interface, or loop through the global addresses we
currently have on our interface and associate it with one of those addresses.
We need to have a special case here for the default route so that it gets used,
we do this by setting the masksize to 0 to mean it encompasses all networks.
The routing code will automatically select the best route so if there is a
closer match we will use that.
With this patch I can now talk to ipv6 addresses outside of my local network.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
server cannot be NULL at this point (we return error earlier if it is).
Also structure is zalloc'ed, so no need to explicitly initialize
members to 0.
Found by: Coverity scan.
CID: 73837
Many routers have long router advertisment interval configured by
default. The Neighbor Discovery protocol (RFC4861) has defined default
MaxRtrAdvInterval value as 600 seconds and
MinRtrAdvInterval as 0.33*MaxRtrAdvInterval. This makes
net_ipv6_autoconf fails more often than not as currently it passively
listens the RA message to perfom address autoconfiguration.
This patch tries to send router solicitation to overcome the problem of
long RA interval.
v2:
use cpu_to_be macro for network byte order conversion
add missing error handling
In net/net.c there is a while (1) that only exits if there is a stop
condition and more then 10 packages or if there is no package received.
If GRUB is idle and enter in this loop, the only condition to leave is
if it doesn't have incoming packages. In a network with heavy traffic
this never happens.
strncpy.
* grub-core/fs/jfs.c (grub_jfs_lookup_symlink): Likewise.
* grub-core/kern/misc.c (grub_strncpy): Move from here ...
* include/grub/misc.h (grub_strncpy): ... to here. Make inline.
* grub-core/net/net.c (grub_net_addr_to_str): Use COMPILE_TIME_ASSERT
+ strcpy rather than strncpy.
* grub-core/net/net.c (receive_packets): Decrease the stop to 10
packets but stop only if stop condition is satisfied.
(grub_net_fs_read_real): Call packets_pulled after real read. Use
`stall' instead of `eof' as stop condition.
* grub-core/net/http.c (parse_line): Set `stall' on EOF.
(http_err): Likewise.
* grub-core/net/tftp.c (ack): Replace the first argument with data
instead of socket.
(tftp_receive): Stall if too many packets are in wait queue.
(tftp_packets_pulled): New function.
(grub_tftp_protocol): Set packets_pulled.
* include/grub/net.h (grub_net_packets): New field count.
(grub_net_put_packet): Increment count.
(grub_net_remove_packet): Likewise.
(grub_net_app_protocol): New field `packets_pulled'.
(grub_net): New field `stall'.
* grub-core/net/bootp.c (parse_dhcp_vendor): Parse mask.
(grub_net_configure_by_dhcp_ack): Use mask and grub_net_add_ipv4_local.
* grub-core/net/net.c (grub_net_add_addr): Split creating local route
into ...
(grub_net_add_ipv4_local): ... this.
(grub_cmd_addaddr): Use grub_net_add_ipv4_local.
* include/grub/net.h (GRUB_NET_BOOTP_NETMASK): New enum value.
(grub_net_add_ipv4_local): New proto.
* include/grub/net.h (grub_net_poll_cards): New argument stop_condition.
All users updated.
* grub-core/net/arp.c (have_pending): New var.
(pending_req): Likewise.
(grub_net_arp_send_request): Fill pending_req and use have_pending as
stop indicator.
(grub_net_arp_receive): Set have_pending.
* grub-core/net/dns.c (recv_data): New field stop.
(recv_hook): Set stop.
(grub_net_dns_lookup): Init stop and use as stop condition.
* grub-core/net/http.c (http_establish): Use headers_recv as stop
condition.
* grub-core/net/net.c (grub_net_poll_cards): New argument
stop_condition. Stop when it goes true.
* grub-core/net/tcp.c (grub_net_tcp_open): Use `established' as stop
indicator.
* grub-core/net/tftp.c (tftp_open): Use `have_oack' as stop indicator.
compact and more efficient code.
* grub-core/kern/list.c (grub_list_push): Moved from here ...
* include/grub/list.h (grub_list_push): ... to here. Set prev.
(grub_list_remove): Moved from here ...
* include/grub/list.h (grub_list_remove): ... here. Use and set prev.
(grub_prio_list_insert): Set prev.
* include/grub/list.h (grub_list): Add prev. All users updated.
