[PPP]: add PPP MPPE encryption module (b3f9b92a) · Commits · 戴 / test

drivers/net/Kconfig

+13 −0

Original line number	Diff line number	Diff line
		@@ -2523,6 +2523,19 @@ config PPP_BSDCOMP
		module; it is called bsd_comp and will show up in the directory
		modules once you have said "make modules". If unsure, say N.

		config PPP_MPPE
		tristate "PPP MPPE compression (encryption) (EXPERIMENTAL)"
		depends on PPP && EXPERIMENTAL
		select CRYPTO
		select CRYPTO_SHA1
		select CRYPTO_ARC4
		---help---
		Support for the MPPE Encryption protocol, as employed by the
		Microsoft Point-to-Point Tunneling Protocol.

		See http://pptpclient.sourceforge.net/ for information on
		configuring PPTP clients and servers to utilize this method.

		config PPPOE
		tristate "PPP over Ethernet (EXPERIMENTAL)"
		depends on EXPERIMENTAL && PPP

drivers/net/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -112,6 +112,7 @@ obj-$(CONFIG_PPP_ASYNC) += ppp_async.o
		obj-$(CONFIG_PPP_SYNC_TTY) += ppp_synctty.o
		obj-$(CONFIG_PPP_DEFLATE) += ppp_deflate.o
		obj-$(CONFIG_PPP_BSDCOMP) += bsd_comp.o
		obj-$(CONFIG_PPP_MPPE) += ppp_mppe.o
		obj-$(CONFIG_PPPOE) += pppox.o pppoe.o

		obj-$(CONFIG_SLIP) += slip.o

drivers/net/ppp_generic.c

+64 −24

Original line number	Diff line number	Diff line
		@@ -137,13 +137,14 @@ struct ppp {

		/*
		* Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
		* SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP.
		* SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
		* SC_MUST_COMP
		* Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
		* Bits in xstate: SC_COMP_RUN
		*/
		#define SC_FLAG_BITS (SC_NO_TCP_CCID\|SC_CCP_OPEN\|SC_CCP_UP\|SC_LOOP_TRAFFIC \
		\|SC_MULTILINK\|SC_MP_SHORTSEQ\|SC_MP_XSHORTSEQ \
		\|SC_COMP_TCP\|SC_REJ_COMP_TCP)
		\|SC_COMP_TCP\|SC_REJ_COMP_TCP\|SC_MUST_COMP)

		/*
		* Private data structure for each channel.
		@@ -1027,6 +1028,56 @@ ppp_xmit_process(struct ppp *ppp)
		ppp_xmit_unlock(ppp);
		}

		static inline struct sk_buff *
		pad_compress_skb(struct ppp ppp, struct sk_buff skb)
		{
		struct sk_buff *new_skb;
		int len;
		int new_skb_size = ppp->dev->mtu +
		ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
		int compressor_skb_size = ppp->dev->mtu +
		ppp->xcomp->comp_extra + PPP_HDRLEN;
		new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
		if (!new_skb) {
		if (net_ratelimit())
		printk(KERN_ERR "PPP: no memory (comp pkt)\n");
		return NULL;
		}
		if (ppp->dev->hard_header_len > PPP_HDRLEN)
		skb_reserve(new_skb,
		ppp->dev->hard_header_len - PPP_HDRLEN);

		/* compressor still expects A/C bytes in hdr */
		len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
		new_skb->data, skb->len + 2,
		compressor_skb_size);
		if (len > 0 && (ppp->flags & SC_CCP_UP)) {
		kfree_skb(skb);
		skb = new_skb;
		skb_put(skb, len);
		skb_pull(skb, 2); /* pull off A/C bytes */
		} else if (len == 0) {
		/* didn't compress, or CCP not up yet */
		kfree_skb(new_skb);
		new_skb = skb;
		} else {
		/*
		* (len < 0)
		* MPPE requires that we do not send unencrypted
		* frames. The compressor will return -1 if we
		* should drop the frame. We cannot simply test
		* the compress_proto because MPPE and MPPC share
		* the same number.
		*/
		if (net_ratelimit())
		printk(KERN_ERR "ppp: compressor dropped pkt\n");
		kfree_skb(skb);
		kfree_skb(new_skb);
		new_skb = NULL;
		}
		return new_skb;
		}

		/*
		* Compress and send a frame.
		* The caller should have locked the xmit path,
		@@ -1113,29 +1164,14 @@ ppp_send_frame(struct ppp ppp, struct sk_buff skb)
		/* try to do packet compression */
		if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
		&& proto != PPP_LCP && proto != PPP_CCP) {
		new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len,
		GFP_ATOMIC);
		if (new_skb == 0) {
		printk(KERN_ERR "PPP: no memory (comp pkt)\n");
		if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
		if (net_ratelimit())
		printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
		goto drop;
		}
		if (ppp->dev->hard_header_len > PPP_HDRLEN)
		skb_reserve(new_skb,
		ppp->dev->hard_header_len - PPP_HDRLEN);

		/* compressor still expects A/C bytes in hdr */
		len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
		new_skb->data, skb->len + 2,
		ppp->dev->mtu + PPP_HDRLEN);
		if (len > 0 && (ppp->flags & SC_CCP_UP)) {
		kfree_skb(skb);
		skb = new_skb;
		skb_put(skb, len);
		skb_pull(skb, 2); /* pull off A/C bytes */
		} else {
		/* didn't compress, or CCP not up yet */
		kfree_skb(new_skb);
		}
		skb = pad_compress_skb(ppp, skb);
		if (!skb)
		goto drop;
		}

		/*
		@@ -1155,6 +1191,7 @@ ppp_send_frame(struct ppp ppp, struct sk_buff skb)
		return;

		drop:
		if (skb)
		kfree_skb(skb);
		++ppp->stats.tx_errors;
		}
		@@ -1552,6 +1589,9 @@ ppp_receive_nonmp_frame(struct ppp ppp, struct sk_buff skb)
		&& (ppp->rstate & (SC_DC_FERROR \| SC_DC_ERROR)) == 0)
		skb = ppp_decompress_frame(ppp, skb);

		if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
		goto err;

		proto = PPP_PROTO(skb);
		switch (proto) {
		case PPP_VJC_COMP:

drivers/net/ppp_mppe.c

0 → 100644

+724 −0

File added.

Preview size limit exceeded, changes collapsed.

drivers/net/ppp_mppe.h

0 → 100644

+86 −0

Original line number	Diff line number	Diff line
		#define MPPE_PAD 4 /* MPPE growth per frame */
		#define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */

		/* option bits for ccp_options.mppe */
		#define MPPE_OPT_40 0x01 /* 40 bit */
		#define MPPE_OPT_128 0x02 /* 128 bit */
		#define MPPE_OPT_STATEFUL 0x04 /* stateful mode */
		/* unsupported opts */
		#define MPPE_OPT_56 0x08 /* 56 bit */
		#define MPPE_OPT_MPPC 0x10 /* MPPC compression */
		#define MPPE_OPT_D 0x20 /* Unknown */
		#define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56\|MPPE_OPT_MPPC\|MPPE_OPT_D)
		#define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */

		/*
		* This is not nice ... the alternative is a bitfield struct though.
		* And unfortunately, we cannot share the same bits for the option
		* names above since C and H are the same bit. We could do a u_int32
		* but then we have to do a htonl() all the time and/or we still need
		* to know which octet is which.
		*/
		#define MPPE_C_BIT 0x01 /* MPPC */
		#define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */
		#define MPPE_L_BIT 0x20 /* 40-bit */
		#define MPPE_S_BIT 0x40 /* 128-bit */
		#define MPPE_M_BIT 0x80 /* 56-bit, not supported */
		#define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */

		/* Does not include H bit; used for least significant octet only. */
		#define MPPE_ALL_BITS (MPPE_D_BIT\|MPPE_L_BIT\|MPPE_S_BIT\|MPPE_M_BIT\|MPPE_H_BIT)

		/* Build a CI from mppe opts (see RFC 3078) */
		#define MPPE_OPTS_TO_CI(opts, ci) \
		do { \
		u_char ptr = ci; / u_char[4] */ \
		\
		/* H bit */ \
		if (opts & MPPE_OPT_STATEFUL) \
		*ptr++ = 0x0; \
		else \
		*ptr++ = MPPE_H_BIT; \
		*ptr++ = 0; \
		*ptr++ = 0; \
		\
		/* S,L bits */ \
		*ptr = 0; \
		if (opts & MPPE_OPT_128) \
		*ptr \|= MPPE_S_BIT; \
		if (opts & MPPE_OPT_40) \
		*ptr \|= MPPE_L_BIT; \
		/* M,D,C bits not supported */ \
		} while (/* CONSTCOND */ 0)

		/* The reverse of the above */
		#define MPPE_CI_TO_OPTS(ci, opts) \
		do { \
		u_char ptr = ci; / u_char[4] */ \
		\
		opts = 0; \
		\
		/* H bit */ \
		if (!(ptr[0] & MPPE_H_BIT)) \
		opts \|= MPPE_OPT_STATEFUL; \
		\
		/* S,L bits */ \
		if (ptr[3] & MPPE_S_BIT) \
		opts \|= MPPE_OPT_128; \
		if (ptr[3] & MPPE_L_BIT) \
		opts \|= MPPE_OPT_40; \
		\
		/* M,D,C bits */ \
		if (ptr[3] & MPPE_M_BIT) \
		opts \|= MPPE_OPT_56; \
		if (ptr[3] & MPPE_D_BIT) \
		opts \|= MPPE_OPT_D; \
		if (ptr[3] & MPPE_C_BIT) \
		opts \|= MPPE_OPT_MPPC; \
		\
		/* Other bits */ \
		if (ptr[0] & ~MPPE_H_BIT) \
		opts \|= MPPE_OPT_UNKNOWN; \
		if (ptr[1] \|\| ptr[2]) \
		opts \|= MPPE_OPT_UNKNOWN; \
		if (ptr[3] & ~MPPE_ALL_BITS) \
		opts \|= MPPE_OPT_UNKNOWN; \
		} while (/* CONSTCOND */ 0)

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