patch-2.1.73 linux/net/ipv4/ip_masq_mod.c

• Lines: 317
• Date: Wed Dec 10 09:45:16 1997
• Orig file: v2.1.72/linux/net/ipv4/ip_masq_mod.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.72/linux/net/ipv4/ip_masq_mod.c linux/net/ipv4/ip_masq_mod.c
@@ -0,0 +1,316 @@
+/*
+ *		IP_MASQ_MOD masq modules support
+ *
+ *
+ * Version:	@(#)ip_masq_mod.c  0.02      97/10/30
+ *
+ * Author:	Juan Jose Ciarlante, <jjciarla@raiz.uncu.edu.ar>
+ *
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <net/ip_masq.h>
+#include <net/ip_masq_mod.h>
+#ifdef CONFIG_KERNELD
+#include <linux/kerneld.h>
+#endif
+
+EXPORT_SYMBOL(register_ip_masq_mod);
+EXPORT_SYMBOL(unregister_ip_masq_mod);
+EXPORT_SYMBOL(ip_masq_mod_lkp_link);
+EXPORT_SYMBOL(ip_masq_mod_lkp_unlink);
+
+/*
+ *	Base pointer for registered modules
+ */
+struct ip_masq_mod * ip_masq_mod_reg_base = NULL;
+
+/*
+ *	Base pointer for lookup (subset of above, a module could be
+ *	registered, but it could have no active rule); will avoid
+ *	unnecessary lookups.
+ */
+struct ip_masq_mod * ip_masq_mod_lkp_base = NULL;
+
+int ip_masq_mod_register_proc(struct ip_masq_mod *mmod)
+{
+#ifdef CONFIG_PROC_FS        
+	int ret;
+
+	struct proc_dir_entry *ent = mmod->mmod_proc_ent;
+
+	if (!ent) 
+		return 0;
+	if (!ent->name) {
+		ent->name = mmod->mmod_name;
+		ent->namelen = strlen (mmod->mmod_name);
+	}
+	ret = proc_net_register(ent);
+	if (ret) mmod->mmod_proc_ent = NULL;
+
+	return ret;
+#else
+	return 0;
+#endif
+}
+
+void ip_masq_mod_unregister_proc(struct ip_masq_mod *mmod)
+{
+#ifdef CONFIG_PROC_FS        
+	struct proc_dir_entry *ent = mmod->mmod_proc_ent;
+	if (!ent)
+		return;
+	proc_unregister(proc_net, ent->low_ino);
+#endif
+}
+
+/*
+ *	Link/unlink object for lookups
+ */
+
+int ip_masq_mod_lkp_unlink(struct ip_masq_mod *mmod)
+{
+	struct ip_masq_mod **mmod_p;
+
+	start_bh_atomic();
+
+	for (mmod_p = &ip_masq_mod_lkp_base; *mmod_p ; mmod_p = &(*mmod_p)->next)
+		if (mmod == (*mmod_p))  {
+			*mmod_p = mmod->next;
+			mmod->next = NULL;
+			end_bh_atomic();
+			return 0;
+		}
+
+	end_bh_atomic();
+	return -EINVAL;
+}
+
+int ip_masq_mod_lkp_link(struct ip_masq_mod *mmod)
+{
+	start_bh_atomic();
+
+	mmod->next = ip_masq_mod_lkp_base;
+	ip_masq_mod_lkp_base=mmod;
+
+	end_bh_atomic();
+	return 0;
+}
+
+int register_ip_masq_mod(struct ip_masq_mod *mmod)
+{
+	if (!mmod) {
+		IP_MASQ_ERR("register_ip_masq_mod(): NULL arg\n");
+		return -EINVAL;
+	}
+	if (!mmod->mmod_name) {
+		IP_MASQ_ERR("register_ip_masq_mod(): NULL mmod_name\n");
+		return -EINVAL;
+	}
+	ip_masq_mod_register_proc(mmod);
+
+	mmod->next_reg = ip_masq_mod_reg_base;
+	ip_masq_mod_reg_base=mmod;
+
+	return 0;
+}
+
+int unregister_ip_masq_mod(struct ip_masq_mod *mmod)
+{
+	struct ip_masq_mod **mmod_p;
+
+	if (!mmod) {
+		IP_MASQ_ERR( "unregister_ip_masq_mod(): NULL arg\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * 	Only allow unregistration if it is not referenced
+	 */
+	if (atomic_read(&mmod->refcnt))  {
+		IP_MASQ_ERR( "unregister_ip_masq_mod(): is in use by %d guys. failed\n",
+				atomic_read(&mmod->refcnt));
+		return -EINVAL;
+	}
+
+	/*	
+	 *	Must be already unlinked from lookup list
+	 */
+	if (mmod->next) {
+		IP_MASQ_WARNING("MASQ: unregistering \"%s\" while in lookup list.fixed.",
+			mmod->mmod_name);
+		ip_masq_mod_lkp_unlink(mmod);
+	}
+
+	for (mmod_p = &ip_masq_mod_reg_base; *mmod_p ; mmod_p = &(*mmod_p)->next_reg)
+		if (mmod == (*mmod_p))  {
+			ip_masq_mod_unregister_proc(mmod);
+			*mmod_p = mmod->next_reg;
+			return 0;
+		}
+
+	IP_MASQ_ERR("unregister_ip_masq_mod(%s): not linked \n", mmod->mmod_name);
+	return -EINVAL;
+}
+
+int ip_masq_mod_in_rule(struct iphdr *iph, __u16 *portp)
+{
+	struct ip_masq_mod *mmod;
+	int ret;
+
+	for (mmod=ip_masq_mod_lkp_base;mmod;mmod=mmod->next) {
+		if (!mmod->mmod_in_rule) continue;
+		switch (ret=mmod->mmod_in_rule(iph, portp)) {
+			case IP_MASQ_MOD_NOP:
+				continue;
+			case IP_MASQ_MOD_ACCEPT:
+				return 1;
+			case IP_MASQ_MOD_REJECT:
+				return -1;
+		}
+	}
+	return 0;
+}
+
+int ip_masq_mod_out_rule(struct iphdr *iph, __u16 *portp)
+{
+	struct ip_masq_mod *mmod;
+	int ret;
+
+	for (mmod=ip_masq_mod_lkp_base;mmod;mmod=mmod->next) {
+		if (!mmod->mmod_out_rule) continue;
+		switch (ret=mmod->mmod_out_rule(iph, portp)) {
+			case IP_MASQ_MOD_NOP:
+				continue;
+			case IP_MASQ_MOD_ACCEPT:
+				return 1;
+			case IP_MASQ_MOD_REJECT:
+				return -1;
+		}
+	}
+	return 0;
+}
+
+struct ip_masq * ip_masq_mod_in_create(struct iphdr *iph, __u16 *portp, __u32 maddr)
+{
+	struct ip_masq_mod *mmod;
+	struct ip_masq *ms;
+
+	for (mmod=ip_masq_mod_lkp_base;mmod;mmod=mmod->next) {
+		if (!mmod->mmod_in_create) continue;
+		if ((ms=mmod->mmod_in_create(iph, portp, maddr))) {
+			return ms;
+		}
+	}
+	return NULL;
+}
+
+struct ip_masq * ip_masq_mod_out_create(struct iphdr *iph, __u16 *portp, __u32 maddr)
+{
+	struct ip_masq_mod *mmod;
+	struct ip_masq *ms;
+
+	for (mmod=ip_masq_mod_lkp_base;mmod;mmod=mmod->next) {
+		if (!mmod->mmod_out_create) continue;
+		if ((ms=mmod->mmod_out_create(iph, portp, maddr))) {
+			return ms;
+		}
+	}
+	return NULL;
+}
+
+int ip_masq_mod_in_update(struct iphdr *iph, __u16 *portp, struct ip_masq *ms)
+{
+	struct ip_masq_mod *mmod;
+	int ret;
+
+	for (mmod=ip_masq_mod_lkp_base;mmod;mmod=mmod->next) {
+		if (!mmod->mmod_in_update) continue;
+		switch (ret=mmod->mmod_in_update(iph, ms)) {
+			case IP_MASQ_MOD_NOP:
+				continue;
+			case IP_MASQ_MOD_ACCEPT:
+				return 1;
+			case IP_MASQ_MOD_REJECT:
+				return -1;
+		}
+	}
+	return 0;
+}
+
+int ip_masq_mod_out_update(struct iphdr *iph, __u16 *portp,  struct ip_masq *ms)
+{
+	struct ip_masq_mod *mmod;
+	int ret;
+
+	for (mmod=ip_masq_mod_lkp_base;mmod;mmod=mmod->next) {
+		if (!mmod->mmod_out_update) continue;
+		switch (ret=mmod->mmod_out_update(iph, portp, ms)) {
+			case IP_MASQ_MOD_NOP:
+				continue;
+			case IP_MASQ_MOD_ACCEPT:
+				return 1;
+			case IP_MASQ_MOD_REJECT:
+				return -1;
+		}
+	}
+	return 0;
+}
+
+struct ip_masq_mod * ip_masq_mod_getbyname(const char *mmod_name)
+{
+	struct ip_masq_mod * mmod;
+
+	IP_MASQ_DEBUG(1, "searching mmod_name \"%s\"\n", mmod_name);
+	
+	for (mmod=ip_masq_mod_reg_base; mmod ; mmod=mmod->next) {
+		if (mmod->mmod_ctl && *(mmod_name)
+				&& (strcmp(mmod_name, mmod->mmod_name)==0)) {
+			/* HIT */
+			return mmod;
+		}
+	}
+	return NULL;
+}
+
+/*
+ *	Module control entry
+ *	no need to lock (already locked in ip_masq.c)
+ */
+int ip_masq_mod_ctl(int optname, struct ip_fw_masqctl *mctl, int optlen)
+{
+	struct ip_masq_mod * mmod;
+#ifdef CONFIG_KERNELD
+	char kmod_name[IP_MASQ_MOD_NMAX+8];
+#endif
+	/* tappo */
+	mctl->u.mod.name[IP_MASQ_MOD_NMAX-1] = 0;
+
+	mmod = ip_masq_mod_getbyname(mctl->u.mod.name);
+	if (mmod)
+		return mmod->mmod_ctl(optname, mctl, optlen);
+#ifdef CONFIG_KERNELD
+	sprintf(kmod_name,"ip_masq_%s", mctl->u.mod.name);
+
+	IP_MASQ_DEBUG(1, "About to request \"%s\" module\n", kmod_name);
+
+	/* 
+	 *	Let sleep for a while ...
+	 */
+	request_module(kmod_name);
+	mmod = ip_masq_mod_getbyname(mctl->u.mod.name);
+	if (mmod)
+		return mmod->mmod_ctl(optname, mctl, optlen);
+#endif
+	return ESRCH;
+}