Mailing List Archive: iptables: Devel

Re: [PATCH 01/**] libxt_*.so lookup

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yasuyuki.kozakai at toshiba

Jul 30, 2007, 5:25 PM

Post #1 of 6 (882 views)
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Re: [PATCH 01/] libxt_.so lookup*

Hi,

From: Jan Engelhardt <jengelh [at] computergmbh>

> Let the iptable tools search for libxt modules first,
> then for l3-specific modules (libipt, libip6t)
>
> Signed-off-by: Jan Engelhardt <jengelh [at] gmx>

> +static const char *const family_prefix[] = {
> + [AF_UNSPEC] = "xt",
> + [AF_INET] = "ipt",
> + [AF_INET6] = "ip6t",
> +};
> +

Using AF_UNSPEC is attractive. It can save almost samef xtables_{match,target}
as you proposed in other mail. But I prefer to keep things logical. Other
than IPv4 and IPv6 family cannot support almost 'xt_' matches/targets.

> struct xtables_match *find_match(const char *name, enum xt_tryload tryload,
> - struct xtables_rule_match **matches)
> + struct xtables_rule_match **matches,
> + unsigned int family)
> {
> struct xtables_match *ptr;
> const char *icmp6 = "icmp6";
> @@ -292,21 +300,27 @@ struct xtables_match *find_match(const c
> if (!ptr && tryload != DONT_LOAD && tryload != DURING_LOAD) {
> char path[strlen(lib_dir) + sizeof("/.so")
> + strlen(afinfo.libprefix) + strlen(name)];
> - sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix,
> - name);
> - if (dlopen(path, RTLD_NOW)) {
> - /* Found library. If it didn't register itself,
> - maybe they specified target as match. */
> - ptr = find_match(name, DONT_LOAD, NULL);
> -
> - if (!ptr)
> - exit_error(PARAMETER_PROBLEM,
> - "Couldn't load match `%s'\n",
> - name);
> - } else if (tryload == LOAD_MUST_SUCCEED)
> +
> + snprintf(path, sizeof(path), "%s/lib%s_%s.so", lib_dir,
> + family_prefix[AF_UNSPEC], name);

So, here "%s/libxt_%s.so" is enough, and

> + if (dlopen(path, RTLD_NOW) != NULL)
> + /*
> + * Library loaded (and its constructors run).
> + * Try to grab the pointer to the struct.
> + */
> + ptr = find_match(name, DONT_LOAD, NULL, family);
> +
> + if (ptr == NULL && family < ARRAY_SIZE(family_prefix) &&
> + family_prefix[family] != NULL) {
> + snprintf(path, sizeof(path), "%s/lib%s_%s.so",
> + lib_dir, family_prefix[family], name);

let's use afinfo.libprefix.

> + if (dlopen(path, RTLD_NOW) != NULL)
> + ptr = find_match(name, DONT_LOAD, NULL, family);
> + }
> +
> + if (ptr == NULL && tryload == LOAD_MUST_SUCCEED)
> exit_error(PARAMETER_PROBLEM,
> - "Couldn't load match `%s':%s\n",
> - name, dlerror());
> + "Couldn't load match `%s'\n", name);
> }
> #else
> if (ptr && !ptr->loaded) {

-- Yasuyuki Kozakai

jengelh at computergmbh

Jul 31, 2007, 12:59 AM

Post #2 of 6 (830 views)
Permalink

Re: [PATCH 01/] libxt_.so lookup* [In reply to]

On Jul 31 2007 09:25, Yasuyuki KOZAKAI wrote:
>> + snprintf(path, sizeof(path), "%s/lib%s_%s.so", lib_dir,
>> + family_prefix[AF_UNSPEC], name);
>
>So, here "%s/libxt_%s.so" is enough, and
>
>> + if (ptr == NULL && family < ARRAY_SIZE(family_prefix) &&
>> + family_prefix[family] != NULL) {
>> + snprintf(path, sizeof(path), "%s/lib%s_%s.so",
>> + lib_dir, family_prefix[family], name);
>
>let's use afinfo.libprefix.
>

Jan
===

Let the iptable tools search for libxt modules first,
then for l3-specific modules (libipt, libip6t)

Signed-off-by: Jan Engelhardt <jengelh [at] gmx>

---
include/xtables.h | 6 +++-
ip6tables-save.c | 4 +--
ip6tables.c | 22 ++++++++---------
iptables-save.c | 4 +--
iptables.c | 22 ++++++++---------
xtables.c | 68 ++++++++++++++++++++++++++++++------------------------
6 files changed, 68 insertions(+), 58 deletions(-)

Index: iptables/include/xtables.h
===================================================================
--- iptables.orig/include/xtables.h
+++ iptables/include/xtables.h
@@ -191,8 +191,10 @@ extern void xtables_register_match(struc
extern void xtables_register_target(struct xtables_target *me);

extern struct xtables_match *find_match(const char *name, enum xt_tryload,
- struct xtables_rule_match **match);
-extern struct xtables_target *find_target(const char *name, enum xt_tryload);
+ struct xtables_rule_match **match,
+ unsigned int family);
+extern struct xtables_target *find_target(const char *name, enum xt_tryload,
+ unsigned int family);

extern int string_to_number_ll(const char *s,
unsigned long long min,
Index: iptables/ip6tables-save.c
===================================================================
--- iptables.orig/ip6tables-save.c
+++ iptables/ip6tables-save.c
@@ -100,7 +100,7 @@ static int print_match(const struct ip6t
const struct ip6t_ip6 *ip)
{
struct ip6tables_match *match
- = find_match(e->u.user.name, TRY_LOAD, NULL);
+ = find_match(e->u.user.name, TRY_LOAD, NULL, "ip6t");

if (match) {
printf("-m %s ", e->u.user.name);
@@ -196,7 +196,7 @@ static void print_rule(const struct ip6t
t = ip6t_get_target((struct ip6t_entry *)e);
if (t->u.user.name[0]) {
struct ip6tables_target *target
- = find_target(t->u.user.name, TRY_LOAD);
+ = find_target(t->u.user.name, TRY_LOAD, AF_INET6);

if (!target) {
fprintf(stderr, "Can't find library for target `%s'\n",
Index: iptables/ip6tables.c
===================================================================
--- iptables.orig/ip6tables.c
+++ iptables/ip6tables.c
@@ -700,9 +700,9 @@ find_proto(const char *pname, enum ip6t_
char *protoname = proto_to_name(proto, nolookup);

if (protoname)
- return find_match(protoname, tryload, matches);
+ return find_match(protoname, tryload, matches, AF_INET6);
} else
- return find_match(pname, tryload, matches);
+ return find_match(pname, tryload, matches, AF_INET6);

return NULL;
}
@@ -929,7 +929,7 @@ print_match(const struct ip6t_entry_matc
const struct ip6t_ip6 *ip,
int numeric)
{
- struct ip6tables_match *match = find_match(m->u.user.name, TRY_LOAD, NULL);
+ struct ip6tables_match *match = find_match(m->u.user.name, TRY_LOAD, NULL, AF_INET6);

if (match) {
if (match->print)
@@ -958,9 +958,9 @@ print_firewall(const struct ip6t_entry *
char buf[BUFSIZ];

if (!ip6tc_is_chain(targname, handle))
- target = find_target(targname, TRY_LOAD);
+ target = find_target(targname, TRY_LOAD, AF_INET6);
else
- target = find_target(IP6T_STANDARD_TARGET, LOAD_MUST_SUCCEED);
+ target = find_target(IP6T_STANDARD_TARGET, LOAD_MUST_SUCCEED, AF_INET6);

t = ip6t_get_target((struct ip6t_entry *)fw);
flags = fw->ipv6.flags;
@@ -1513,7 +1513,7 @@ int do_command6(int argc, char *argv[],
exit_error(PARAMETER_PROBLEM,
"chain name not allowed to start "
"with `%c'\n", *optarg);
- if (find_target(optarg, TRY_LOAD))
+ if (find_target(optarg, TRY_LOAD, AF_INET6))
exit_error(PARAMETER_PROBLEM,
"chain name may not clash "
"with target name\n");
@@ -1564,7 +1564,7 @@ int do_command6(int argc, char *argv[],

/* ip6tables -p icmp -h */
if (!matches && protocol)
- find_match(protocol, TRY_LOAD, &matches);
+ find_match(protocol, TRY_LOAD, &matches, AF_INET6);

exit_printhelp(matches);

@@ -1615,7 +1615,7 @@ int do_command6(int argc, char *argv[],
invert);
jumpto = parse_target(optarg);
/* TRY_LOAD (may be chain name) */
- target = find_target(jumpto, TRY_LOAD);
+ target = find_target(jumpto, TRY_LOAD, AF_INET6);

if (target) {
size_t size;
@@ -1665,7 +1665,7 @@ int do_command6(int argc, char *argv[],
exit_error(PARAMETER_PROBLEM,
"unexpected ! flag before --match");

- m = find_match(optarg, LOAD_MUST_SUCCEED, &matches);
+ m = find_match(optarg, LOAD_MUST_SUCCEED, &matches, AF_INET6);
size = IP6T_ALIGN(sizeof(struct ip6t_entry_match))
+ m->size;
m->m = fw_calloc(1, size);
@@ -1940,7 +1940,7 @@ int do_command6(int argc, char *argv[],
size_t size;

target = find_target(IP6T_STANDARD_TARGET,
- LOAD_MUST_SUCCEED);
+ LOAD_MUST_SUCCEED, AF_INET6);

size = sizeof(struct ip6t_entry_target)
+ target->size;
@@ -1956,7 +1956,7 @@ int do_command6(int argc, char *argv[],
* We cannot know if the plugin is corrupt, non
* existant OR if the user just misspelled a
* chain. */
- find_target(jumpto, LOAD_MUST_SUCCEED);
+ find_target(jumpto, LOAD_MUST_SUCCEED, AF_INET6);
} else {
e = generate_entry(&fw, matches, target->t);
free(target->t);
Index: iptables/iptables-save.c
===================================================================
--- iptables.orig/iptables-save.c
+++ iptables/iptables-save.c
@@ -119,7 +119,7 @@ static int print_match(const struct ipt_
const struct ipt_ip *ip)
{
struct iptables_match *match
- = find_match(e->u.user.name, TRY_LOAD, NULL);
+ = find_match(e->u.user.name, TRY_LOAD, NULL, AF_INET);

if (match) {
printf("-m %s ", e->u.user.name);
@@ -207,7 +207,7 @@ static void print_rule(const struct ipt_
t = ipt_get_target((struct ipt_entry *)e);
if (t->u.user.name[0]) {
struct iptables_target *target
- = find_target(t->u.user.name, TRY_LOAD);
+ = find_target(t->u.user.name, TRY_LOAD, AF_INET);

if (!target) {
fprintf(stderr, "Can't find library for target `%s'\n",
Index: iptables/iptables.c
===================================================================
--- iptables.orig/iptables.c
+++ iptables/iptables.c
@@ -687,9 +687,9 @@ find_proto(const char *pname, enum ipt_t
char *protoname = proto_to_name(proto, nolookup);

if (protoname)
- return find_match(protoname, tryload, matches);
+ return find_match(protoname, tryload, matches, AF_INET);
} else
- return find_match(pname, tryload, matches);
+ return find_match(pname, tryload, matches, AF_INET);

return NULL;
}
@@ -967,7 +967,7 @@ print_match(const struct ipt_entry_match
const struct ipt_ip *ip,
int numeric)
{
- struct iptables_match *match = find_match(m->u.user.name, TRY_LOAD, NULL);
+ struct iptables_match *match = find_match(m->u.user.name, TRY_LOAD, NULL, AF_INET);

if (match) {
if (match->print)
@@ -996,9 +996,9 @@ print_firewall(const struct ipt_entry *f
char buf[BUFSIZ];

if (!iptc_is_chain(targname, handle))
- target = find_target(targname, TRY_LOAD);
+ target = find_target(targname, TRY_LOAD, AF_INET);
else
- target = find_target(IPT_STANDARD_TARGET, LOAD_MUST_SUCCEED);
+ target = find_target(IPT_STANDARD_TARGET, LOAD_MUST_SUCCEED, AF_INET);

t = ipt_get_target((struct ipt_entry *)fw);
flags = fw->ip.flags;
@@ -1569,7 +1569,7 @@ int do_command(int argc, char *argv[], c
exit_error(PARAMETER_PROBLEM,
"chain name not allowed to start "
"with `%c'\n", *optarg);
- if (find_target(optarg, TRY_LOAD))
+ if (find_target(optarg, TRY_LOAD, AF_INET))
exit_error(PARAMETER_PROBLEM,
"chain name may not clash "
"with target name\n");
@@ -1620,7 +1620,7 @@ int do_command(int argc, char *argv[], c

/* iptables -p icmp -h */
if (!matches && protocol)
- find_match(protocol, TRY_LOAD, &matches);
+ find_match(protocol, TRY_LOAD, &matches, AF_INET);

exit_printhelp(matches);

@@ -1673,7 +1673,7 @@ int do_command(int argc, char *argv[], c
invert);
jumpto = parse_target(optarg);
/* TRY_LOAD (may be chain name) */
- target = find_target(jumpto, TRY_LOAD);
+ target = find_target(jumpto, TRY_LOAD, AF_INET);

if (target) {
size_t size;
@@ -1731,7 +1731,7 @@ int do_command(int argc, char *argv[], c
exit_error(PARAMETER_PROBLEM,
"unexpected ! flag before --match");

- m = find_match(optarg, LOAD_MUST_SUCCEED, &matches);
+ m = find_match(optarg, LOAD_MUST_SUCCEED, &matches, AF_INET);
size = IPT_ALIGN(sizeof(struct ipt_entry_match))
+ m->size;
m->m = fw_calloc(1, size);
@@ -2005,7 +2005,7 @@ int do_command(int argc, char *argv[], c
size_t size;

target = find_target(IPT_STANDARD_TARGET,
- LOAD_MUST_SUCCEED);
+ LOAD_MUST_SUCCEED, AF_INET);

size = sizeof(struct ipt_entry_target)
+ target->size;
@@ -2029,7 +2029,7 @@ int do_command(int argc, char *argv[], c
exit_error(PARAMETER_PROBLEM,
"goto '%s' is not a chain\n", jumpto);
#endif
- find_target(jumpto, LOAD_MUST_SUCCEED);
+ find_target(jumpto, LOAD_MUST_SUCCEED, AF_INET);
} else {
e = generate_entry(&fw, matches, target->t);
free(target->t);
Index: iptables/xtables.c
===================================================================
--- iptables.orig/xtables.c
+++ iptables/xtables.c
@@ -31,6 +31,7 @@

#include <xtables.h>

+#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
#define NPROTO 255

#ifndef PROC_SYS_MODPROBE
@@ -256,7 +257,8 @@ void parse_interface(const char *arg, ch
}

struct xtables_match *find_match(const char *name, enum xt_tryload tryload,
- struct xtables_rule_match **matches)
+ struct xtables_rule_match **matches,
+ unsigned int family)
{
struct xtables_match *ptr;
const char *icmp6 = "icmp6";
@@ -292,21 +294,25 @@ struct xtables_match *find_match(const c
if (!ptr && tryload != DONT_LOAD && tryload != DURING_LOAD) {
char path[strlen(lib_dir) + sizeof("/.so")
+ strlen(afinfo.libprefix) + strlen(name)];
- sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix,
- name);
- if (dlopen(path, RTLD_NOW)) {
- /* Found library. If it didn't register itself,
- maybe they specified target as match. */
- ptr = find_match(name, DONT_LOAD, NULL);
-
- if (!ptr)
- exit_error(PARAMETER_PROBLEM,
- "Couldn't load match `%s'\n",
- name);
- } else if (tryload == LOAD_MUST_SUCCEED)
+
+ snprintf(path, sizeof(path), "%s/libxt_%s.so", lib_dir, name);
+ if (dlopen(path, RTLD_NOW) != NULL)
+ /*
+ * Library loaded (and its constructors run).
+ * Try to grab the pointer to the struct.
+ */
+ ptr = find_match(name, DONT_LOAD, NULL, family);
+
+ if (ptr == NULL) {
+ snprintf(path, sizeof(path), "%s/%s%s.so",
+ lib_dir, afinfo.libprefix, name);
+ if (dlopen(path, RTLD_NOW) != NULL)
+ ptr = find_match(name, DONT_LOAD, NULL, family);
+ }
+
+ if (ptr == NULL && tryload == LOAD_MUST_SUCCEED)
exit_error(PARAMETER_PROBLEM,
- "Couldn't load match `%s':%s\n",
- name, dlerror());
+ "Couldn't load match `%s'\n", name);
}
#else
if (ptr && !ptr->loaded) {
@@ -341,7 +347,8 @@ struct xtables_match *find_match(const c
}

-struct xtables_target *find_target(const char *name, enum xt_tryload tryload)
+struct xtables_target *find_target(const char *name, enum xt_tryload tryload,
+ unsigned int family)
{
struct xtables_target *ptr;

@@ -362,19 +369,20 @@ struct xtables_target *find_target(const
if (!ptr && tryload != DONT_LOAD && tryload != DURING_LOAD) {
char path[strlen(lib_dir) + sizeof("/.so")
+ strlen(afinfo.libprefix) + strlen(name)];
- sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix, name);
- if (dlopen(path, RTLD_NOW)) {
- /* Found library. If it didn't register itself,
- maybe they specified match as a target. */
- ptr = find_target(name, DONT_LOAD);
- if (!ptr)
- exit_error(PARAMETER_PROBLEM,
- "Couldn't load target `%s'\n",
- name);
- } else if (tryload == LOAD_MUST_SUCCEED)
+
+ snprintf(path, sizeof(path), "%s/libxt_%s.so", lib_dir, name);
+ if (dlopen(path, RTLD_NOW) != NULL)
+ ptr = find_target(name, DONT_LOAD, family);
+
+ if (ptr == NULL) {
+ snprintf(path, sizeof(path), "%s/%s%s.so",
+ lib_dir, afinfo.libprefix, name);
+ if (dlopen(path, RTLD_NOW) != NULL)
+ ptr = find_target(name, DONT_LOAD, family);
+ }
+ if (ptr == NULL && tryload == LOAD_MUST_SUCCEED)
exit_error(PARAMETER_PROBLEM,
- "Couldn't load target `%s':%s\n",
- name, dlerror());
+ "Couldn't load target `%s'\n", name);
}
#else
if (ptr && !ptr->loaded) {
@@ -472,7 +480,7 @@ void xtables_register_match(struct xtabl
if (me->family != afinfo.family)
return;

- old = find_match(me->name, DURING_LOAD, NULL);
+ old = find_match(me->name, DURING_LOAD, NULL, me->family);
if (old) {
if (old->revision == me->revision) {
fprintf(stderr,
@@ -538,7 +546,7 @@ void xtables_register_target(struct xtab
if (me->family != afinfo.family)
return;

- old = find_target(me->name, DURING_LOAD);
+ old = find_target(me->name, DURING_LOAD, me->family);
if (old) {
struct xtables_target **i;

yasuyuki.kozakai at toshiba

Aug 1, 2007, 7:40 AM

Post #3 of 6 (827 views)
Permalink

Re: [PATCH 01/] libxt_.so lookup* [In reply to]

From: Jan Engelhardt <jengelh [at] computergmbh>

>
> On Jul 31 2007 09:25, Yasuyuki KOZAKAI wrote:
> >> + snprintf(path, sizeof(path), "%s/lib%s_%s.so", lib_dir,
> >> + family_prefix[AF_UNSPEC], name);
> >
> >So, here "%s/libxt_%s.so" is enough, and
> >
> >> + if (ptr == NULL && family < ARRAY_SIZE(family_prefix) &&
> >> + family_prefix[family] != NULL) {
> >> + snprintf(path, sizeof(path), "%s/lib%s_%s.so",
> >> + lib_dir, family_prefix[family], name);
> >
> >let's use afinfo.libprefix.
> >

> struct xtables_match *find_match(const char *name, enum xt_tryload tryload,
> - struct xtables_rule_match **matches)
> + struct xtables_rule_match **matches,
> + unsigned int family)
> {
> struct xtables_match *ptr;
> const char *icmp6 = "icmp6";
> @@ -292,21 +294,25 @@ struct xtables_match *find_match(const c
> if (!ptr && tryload != DONT_LOAD && tryload != DURING_LOAD) {
> char path[strlen(lib_dir) + sizeof("/.so")
> + strlen(afinfo.libprefix) + strlen(name)];
> - sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix,
> - name);
> - if (dlopen(path, RTLD_NOW)) {
> - /* Found library. If it didn't register itself,
> - maybe they specified target as match. */
> - ptr = find_match(name, DONT_LOAD, NULL);
> -
> - if (!ptr)
> - exit_error(PARAMETER_PROBLEM,
> - "Couldn't load match `%s'\n",
> - name);
> - } else if (tryload == LOAD_MUST_SUCCEED)
> +
> + snprintf(path, sizeof(path), "%s/libxt_%s.so", lib_dir, name);
> + if (dlopen(path, RTLD_NOW) != NULL)
> + /*
> + * Library loaded (and its constructors run).
> + * Try to grab the pointer to the struct.
> + */
> + ptr = find_match(name, DONT_LOAD, NULL, family);
> +
> + if (ptr == NULL) {
> + snprintf(path, sizeof(path), "%s/%s%s.so",
> + lib_dir, afinfo.libprefix, name);
> + if (dlopen(path, RTLD_NOW) != NULL)
> + ptr = find_match(name, DONT_LOAD, NULL, family);
> + }
> +
> + if (ptr == NULL && tryload == LOAD_MUST_SUCCEED)
> exit_error(PARAMETER_PROBLEM,
> - "Couldn't load match `%s':%s\n",
> - name, dlerror());
> + "Couldn't load match `%s'\n", name);
> }
> #else
> if (ptr && !ptr->loaded) {

The argument 'family' has no effect. And this change makes possible to
remove links from libxt_*.so to libip[6]t_*.so as you proposed.

How about following ?

---
extensions/Makefile | 12 ------------
xtables.c | 37 ++++++++++++++++++++++---------------
2 files changed, 22 insertions(+), 27 deletions(-)

diff --git a/extensions/Makefile b/extensions/Makefile
index 49e95ca..36c9b44 100644
--- a/extensions/Makefile
+++ b/extensions/Makefile
@@ -56,14 +56,12 @@ SHARED_LIBS+=$(foreach T,$(PF_EXT_SLIB),extensions/libipt_$(T).so)
SHARED_SE_LIBS+=$(foreach T,$(PF_EXT_SE_SLIB),extensions/libipt_$(T).so)
EXTRA_INSTALLS+=$(foreach T, $(PF_EXT_SLIB), $(DEST_IPT_LIBDIR)/libipt_$(T).so)
EXTRA_INSTALLS+=$(foreach T, $(PF_EXT_SE_SLIB), $(DEST_IPT_LIBDIR)/libipt_$(T).so)
-EXTRA_INSTALLS+=$(foreach T, $(PFX_EXT_SLIB), $(DEST_IPT_LIBDIR)/libipt_$(T).so)

ifeq ($(DO_IPV6), 1)
SHARED_LIBS+=$(foreach T,$(PF6_EXT_SLIB),extensions/libip6t_$(T).so)
SHARED_SE_LIBS+=$(foreach T,$(PF6_EXT_SE_SLIB),extensions/libip6t_$(T).so)
EXTRA_INSTALLS+=$(foreach T, $(PF6_EXT_SLIB), $(DEST_IPT_LIBDIR)/libip6t_$(T).so)
EXTRA_INSTALLS+=$(foreach T, $(PF6_EXT_SE_SLIB), $(DEST_IPT_LIBDIR)/libip6t_$(T).so)
-EXTRA_INSTALLS+=$(foreach T, $(PFX_EXT_SLIB), $(DEST_IPT_LIBDIR)/libip6t_$(T).so)
endif

SHARED_LIBS+=$(foreach T,$(PFX_EXT_SLIB),extensions/libxt_$(T).so)
@@ -192,16 +190,6 @@ extensions/libip6t_matches.man: $(patsubst %, extensions/libip6t_%.man, $(PF6_EX
done ;\
fi >>extensions/libip6t_matches.man

-PF_XTLIBS=$(foreach T, $(PFX_EXT_SLIB), $(DEST_IPT_LIBDIR)/libipt_$(T).so)
-$(PF_XTLIBS): $(DEST_IPT_LIBDIR)/libipt_%.so : $(DEST_IPT_LIBDIR)/libxt_%.so
- @[ -d $(DEST_IPT_LIBDIR)/ ] || mkdir -p $(DEST_IPT_LIBDIR)/
- ln -sf $< $@
-
-PF6_XTLIBS=$(foreach T, $(PFX_EXT_SLIB), $(DEST_IPT_LIBDIR)/libip6t_$(T).so)
-$(PF6_XTLIBS): $(DEST_IPT_LIBDIR)/libip6t_%.so : $(DEST_IPT_LIBDIR)/libxt_%.so
- @[ -d $(DEST_IPT_LIBDIR)/ ] || mkdir -p $(DEST_IPT_LIBDIR)/
- ln -sf $< $@
-
$(DEST_IPT_LIBDIR)/libipt_%.so: extensions/libipt_%.so
@[ -d $(DEST_IPT_LIBDIR)/ ] || mkdir -p $(DEST_IPT_LIBDIR)/
cp $< $@
diff --git a/xtables.c b/xtables.c
index baee483..58b4e81 100644
--- a/xtables.c
+++ b/xtables.c
@@ -292,18 +292,21 @@ struct xtables_match *find_match(const char *name, enum xt_tryload tryload,
if (!ptr && tryload != DONT_LOAD && tryload != DURING_LOAD) {
char path[strlen(lib_dir) + sizeof("/.so")
+ strlen(afinfo.libprefix) + strlen(name)];
- sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix,
- name);
- if (dlopen(path, RTLD_NOW)) {
+
+ sprintf(path, "%s/libxt_%s.so", lib_dir, name);
+ if (dlopen(path, RTLD_NOW) != NULL)
/* Found library. If it didn't register itself,
maybe they specified target as match. */
ptr = find_match(name, DONT_LOAD, NULL);

- if (!ptr)
- exit_error(PARAMETER_PROBLEM,
- "Couldn't load match `%s'\n",
- name);
- } else if (tryload == LOAD_MUST_SUCCEED)
+ if (ptr == NULL) {
+ sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix,
+ name);
+ if (dlopen(path, RTLD_NOW) != NULL)
+ ptr = find_match(name, DONT_LOAD, NULL);
+ }
+
+ if (ptr == NULL && tryload == LOAD_MUST_SUCCEED)
exit_error(PARAMETER_PROBLEM,
"Couldn't load match `%s':%s\n",
name, dlerror());
@@ -362,16 +365,20 @@ struct xtables_target *find_target(const char *name, enum xt_tryload tryload)
if (!ptr && tryload != DONT_LOAD && tryload != DURING_LOAD) {
char path[strlen(lib_dir) + sizeof("/.so")
+ strlen(afinfo.libprefix) + strlen(name)];
- sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix, name);
- if (dlopen(path, RTLD_NOW)) {
+
+ sprintf(path, "%s/libxt_%s.so", lib_dir, name);
+ if (dlopen(path, RTLD_NOW) != NULL)
/* Found library. If it didn't register itself,
maybe they specified match as a target. */
ptr = find_target(name, DONT_LOAD);
- if (!ptr)
- exit_error(PARAMETER_PROBLEM,
- "Couldn't load target `%s'\n",
- name);
- } else if (tryload == LOAD_MUST_SUCCEED)
+
+ if (ptr == NULL) {
+ sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix,
+ name);
+ if (dlopen(path, RTLD_NOW) != NULL)
+ ptr = find_target(name, DONT_LOAD);
+ }
+ if (ptr == NULL && tryload == LOAD_MUST_SUCCEED)
exit_error(PARAMETER_PROBLEM,
"Couldn't load target `%s':%s\n",
name, dlerror());
--
1.5.2.2

-- Yasuyuki Kozakai

jengelh at computergmbh

Aug 1, 2007, 8:02 AM

Post #4 of 6 (830 views)
Permalink

Re: [PATCH 01/] libxt_.so lookup* [In reply to]

On Aug 1 2007 23:40, Yasuyuki KOZAKAI wrote:
>
>The argument 'family' has no effect. And this change makes possible to
>remove links from libxt_*.so to libip[6]t_*.so as you proposed.

Ah indeed.

>index baee483..58b4e81 100644
>--- a/xtables.c
>+++ b/xtables.c
>@@ -292,18 +292,21 @@ struct xtables_match *find_match(const char *name, enum xt_tryload tryload,
> if (!ptr && tryload != DONT_LOAD && tryload != DURING_LOAD) {
> char path[strlen(lib_dir) + sizeof("/.so")
> + strlen(afinfo.libprefix) + strlen(name)];
>- sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix,
>- name);
>- if (dlopen(path, RTLD_NOW)) {
>+
>+ sprintf(path, "%s/libxt_%s.so", lib_dir, name);
>+ if (dlopen(path, RTLD_NOW) != NULL)

I'd suggest using snprintf(). (Also elsewhere)
But looks ok otherwise.

Jan
--

yasuyuki.kozakai at toshiba

Aug 3, 2007, 8:38 PM

Post #5 of 6 (827 views)
Permalink

Re: [PATCH 01/] libxt_.so lookup* [In reply to]

Hi,

From: Jan Engelhardt <jengelh [at] computergmbh>

> On Aug 1 2007 23:40, Yasuyuki KOZAKAI wrote:
> >
> >The argument 'family' has no effect. And this change makes possible to
> >remove links from libxt_*.so to libip[6]t_*.so as you proposed.
>
> Ah indeed.

Thanks for review. I'll apply that soon.

> >index baee483..58b4e81 100644
> >--- a/xtables.c
> >+++ b/xtables.c
> >@@ -292,18 +292,21 @@ struct xtables_match *find_match(const char *name, enum xt_tryload tryload,
> > if (!ptr && tryload != DONT_LOAD && tryload != DURING_LOAD) {
> > char path[strlen(lib_dir) + sizeof("/.so")
> > + strlen(afinfo.libprefix) + strlen(name)];
> >- sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix,
> >- name);
> >- if (dlopen(path, RTLD_NOW)) {
> >+
> >+ sprintf(path, "%s/libxt_%s.so", lib_dir, name);
> >+ if (dlopen(path, RTLD_NOW) != NULL)
>
> I'd suggest using snprintf(). (Also elsewhere)
> But looks ok otherwise.

I didn't notice that. But why snprintf is necessary here ? We have always
enough space for path[].

Are you afraid of buffer overflow due to incorrect size of path[] ?
If so, we'd also better to check return value of snprintf().

-- Yasuyuki Kozakai

jengelh at computergmbh

Aug 4, 2007, 1:25 AM

Post #6 of 6 (828 views)
Permalink

Re: [PATCH 01/] libxt_.so lookup* [In reply to]

On Aug 4 2007 12:38, Yasuyuki KOZAKAI wrote:
>> >index baee483..58b4e81 100644
>> >--- a/xtables.c
>> >+++ b/xtables.c
>> >@@ -292,18 +292,21 @@ struct xtables_match *find_match(const char *name, enum xt_tryload tryload,
>> > if (!ptr && tryload != DONT_LOAD && tryload != DURING_LOAD) {
>> > char path[strlen(lib_dir) + sizeof("/.so")
>> > + strlen(afinfo.libprefix) + strlen(name)];
>> >- sprintf(path, "%s/%s%s.so", lib_dir, afinfo.libprefix,
>> >- name);
>> >- if (dlopen(path, RTLD_NOW)) {
>> >+
>> >+ sprintf(path, "%s/libxt_%s.so", lib_dir, name);
>> >+ if (dlopen(path, RTLD_NOW) != NULL)
>>
>> I'd suggest using snprintf(). (Also elsewhere)
>> But looks ok otherwise.
>
>I didn't notice that. But why snprintf is necessary here ? We have always
>enough space for path[].

Better safe than sorry. Right, when you path[strlen...] it of course
suffices, but then again you could just write path[PATH_MAX],
because POSIX does not do longer names anyway.

BTW, there is a bug, which is why snprintf _is_ good after all:

>> > char path[strlen(lib_dir) + sizeof("/.so")
>> > + strlen(afinfo.libprefix) + strlen(name)];

strlen("libxt_") might be larger than strlen(afinfo.libprefix).

>Are you afraid of buffer overflow due to incorrect size of path[] ?
>If so, we'd also better to check return value of snprintf().

Possible, but not really needed. If the name was truncated, then
dlopen() will fail and the user wonders "wtf - this is impossible"
and can report the bug.

Jan
--

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