dccp: Registration routines for changing feature values (e8ef967a) · Commits · 戴 / test

net/dccp/ccids/ccid2.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -25,7 +25,7 @@
		/*
		* This implementation should follow RFC 4341
		*/

		#include "../feat.h"
		#include "../ccid.h"
		#include "../dccp.h"
		#include "ccid2.h"
		@@ -147,8 +147,8 @@ static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val)
		DCCP_WARN("Limiting Ack Ratio (%u) to %u\n", val, max_ratio);
		val = max_ratio;
		}
		if (val > 0xFFFF) /* RFC 4340, 11.3 */
		val = 0xFFFF;
		if (val > DCCPF_ACK_RATIO_MAX)
		val = DCCPF_ACK_RATIO_MAX;

		if (val == dp->dccps_l_ack_ratio)
		return;

net/dccp/feat.c

+169 −23

Original line number	Diff line number	Diff line
		@@ -92,6 +92,18 @@ static u8 dccp_feat_type(u8 feat_num)
		return dccp_feat_table[idx].reconciliation;
		}

		static int dccp_feat_default_value(u8 feat_num)
		{
		int idx = dccp_feat_index(feat_num);
		/*
		* There are no default values for unknown features, so encountering a
		* negative index here indicates a serious problem somewhere else.
		*/
		DCCP_BUG_ON(idx < 0);

		return idx < 0 ? 0 : dccp_feat_table[idx].default_value;
		}

		/* copy constructor, fval must not already contain allocated memory */
		static int dccp_feat_clone_sp_val(dccp_feat_val fval, u8 const val, u8 len)
		{
		@@ -155,6 +167,63 @@ static void dccp_feat_entry_destructor(struct dccp_feat_entry *entry)
		* - list is sorted in increasing order of feature number (faster lookup)
		*/

		/**
		* dccp_feat_entry_new - Central list update routine (called by all others)
		* @head: list to add to
		* @feat: feature number
		* @local: whether the local (1) or remote feature with number @feat is meant
		* This is the only constructor and serves to ensure the above invariants.
		*/
		static struct dccp_feat_entry *
		dccp_feat_entry_new(struct list_head *head, u8 feat, bool local)
		{
		struct dccp_feat_entry *entry;

		list_for_each_entry(entry, head, node)
		if (entry->feat_num == feat && entry->is_local == local) {
		dccp_feat_val_destructor(entry->feat_num, &entry->val);
		return entry;
		} else if (entry->feat_num > feat) {
		head = &entry->node;
		break;
		}

		entry = kmalloc(sizeof(*entry), gfp_any());
		if (entry != NULL) {
		entry->feat_num = feat;
		entry->is_local = local;
		list_add_tail(&entry->node, head);
		}
		return entry;
		}

		/**
		* dccp_feat_push_change - Add/overwrite a Change option in the list
		* @fn_list: feature-negotiation list to update
		* @feat: one of %dccp_feature_numbers
		* @local: whether local (1) or remote (0) @feat_num is meant
		* @needs_mandatory: whether to use Mandatory feature negotiation options
		* @fval: pointer to NN/SP value to be inserted (will be copied)
		*/
		static int dccp_feat_push_change(struct list_head *fn_list, u8 feat, u8 local,
		u8 mandatory, dccp_feat_val *fval)
		{
		struct dccp_feat_entry *new = dccp_feat_entry_new(fn_list, feat, local);

		if (new == NULL)
		return -ENOMEM;

		new->feat_num = feat;
		new->is_local = local;
		new->state = FEAT_INITIALISING;
		new->needs_confirm = 0;
		new->empty_confirm = 0;
		new->val = *fval;
		new->needs_mandatory = mandatory;

		return 0;
		}

		static inline void dccp_feat_list_pop(struct dccp_feat_entry *entry)
		{
		list_del(&entry->node);
		@@ -190,6 +259,95 @@ cloning_failed:
		return -ENOMEM;
		}

		static u8 dccp_feat_is_valid_nn_val(u8 feat_num, u64 val)
		{
		switch (feat_num) {
		case DCCPF_ACK_RATIO:
		return val <= DCCPF_ACK_RATIO_MAX;
		case DCCPF_SEQUENCE_WINDOW:
		return val >= DCCPF_SEQ_WMIN && val <= DCCPF_SEQ_WMAX;
		}
		return 0; /* feature unknown - so we can't tell */
		}

		/* check that SP values are within the ranges defined in RFC 4340 */
		static u8 dccp_feat_is_valid_sp_val(u8 feat_num, u8 val)
		{
		switch (feat_num) {
		case DCCPF_CCID:
		return val == DCCPC_CCID2 \|\| val == DCCPC_CCID3;
		/* Type-check Boolean feature values: */
		case DCCPF_SHORT_SEQNOS:
		case DCCPF_ECN_INCAPABLE:
		case DCCPF_SEND_ACK_VECTOR:
		case DCCPF_SEND_NDP_COUNT:
		case DCCPF_DATA_CHECKSUM:
		case DCCPF_SEND_LEV_RATE:
		return val < 2;
		case DCCPF_MIN_CSUM_COVER:
		return val < 16;
		}
		return 0; /* feature unknown */
		}

		static u8 dccp_feat_sp_list_ok(u8 feat_num, u8 const *sp_list, u8 sp_len)
		{
		if (sp_list == NULL \|\| sp_len < 1)
		return 0;
		while (sp_len--)
		if (!dccp_feat_is_valid_sp_val(feat_num, *sp_list++))
		return 0;
		return 1;
		}

		/**
		* __feat_register_nn - Register new NN value on socket
		* @fn: feature-negotiation list to register with
		* @feat: an NN feature from %dccp_feature_numbers
		* @mandatory: use Mandatory option if 1
		* @nn_val: value to register (restricted to 4 bytes)
		* Note that NN features are local by definition (RFC 4340, 6.3.2).
		*/
		static int __feat_register_nn(struct list_head *fn, u8 feat,
		u8 mandatory, u64 nn_val)
		{
		dccp_feat_val fval = { .nn = nn_val };

		if (dccp_feat_type(feat) != FEAT_NN \|\|
		!dccp_feat_is_valid_nn_val(feat, nn_val))
		return -EINVAL;

		/* Don't bother with default values, they will be activated anyway. */
		if (nn_val - (u64)dccp_feat_default_value(feat) == 0)
		return 0;

		return dccp_feat_push_change(fn, feat, 1, mandatory, &fval);
		}

		/**
		* __feat_register_sp - Register new SP value/list on socket
		* @fn: feature-negotiation list to register with
		* @feat: an SP feature from %dccp_feature_numbers
		* @is_local: whether the local (1) or the remote (0) @feat is meant
		* @mandatory: use Mandatory option if 1
		* @sp_val: SP value followed by optional preference list
		* @sp_len: length of @sp_val in bytes
		*/
		static int __feat_register_sp(struct list_head *fn, u8 feat, u8 is_local,
		u8 mandatory, u8 const *sp_val, u8 sp_len)
		{
		dccp_feat_val fval;

		if (dccp_feat_type(feat) != FEAT_SP \|\|
		!dccp_feat_sp_list_ok(feat, sp_val, sp_len))
		return -EINVAL;

		if (dccp_feat_clone_sp_val(&fval, sp_val, sp_len))
		return -ENOMEM;

		return dccp_feat_push_change(fn, feat, is_local, mandatory, &fval);
		}

		int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
		u8 *val, u8 len, gfp_t gfp)
		{
		@@ -726,42 +884,30 @@ out_clean:

		EXPORT_SYMBOL_GPL(dccp_feat_clone);

		static int __dccp_feat_init(struct dccp_minisock *dmsk, u8 type, u8 feat,
		u8 *val, u8 len)
		{
		int rc = -ENOMEM;
		u8 *copy = kmemdup(val, len, GFP_KERNEL);

		if (copy != NULL) {
		rc = dccp_feat_change(dmsk, type, feat, copy, len, GFP_KERNEL);
		if (rc)
		kfree(copy);
		}
		return rc;
		}

		int dccp_feat_init(struct dccp_minisock *dmsk)
		int dccp_feat_init(struct sock *sk)
		{
		struct dccp_sock *dp = dccp_sk(sk);
		struct dccp_minisock *dmsk = dccp_msk(sk);
		int rc;

		INIT_LIST_HEAD(&dmsk->dccpms_pending);
		INIT_LIST_HEAD(&dmsk->dccpms_conf);
		INIT_LIST_HEAD(&dmsk->dccpms_pending); /* XXX no longer used */
		INIT_LIST_HEAD(&dmsk->dccpms_conf); /* XXX no longer used */

		/* CCID L */
		rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_L, DCCPF_CCID,
		rc = __feat_register_sp(&dp->dccps_featneg, DCCPF_CCID, 1, 0,
		&dmsk->dccpms_tx_ccid, 1);
		if (rc)
		goto out;

		/* CCID R */
		rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_R, DCCPF_CCID,
		rc = __feat_register_sp(&dp->dccps_featneg, DCCPF_CCID, 0, 0,
		&dmsk->dccpms_rx_ccid, 1);
		if (rc)
		goto out;

		/* Ack ratio */
		rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_L, DCCPF_ACK_RATIO,
		&dmsk->dccpms_ack_ratio, 1);
		rc = __feat_register_nn(&dp->dccps_featneg, DCCPF_ACK_RATIO, 0,
		dmsk->dccpms_ack_ratio);
		out:
		return rc;
		}

net/dccp/feat.h

+24 −1

Original line number	Diff line number	Diff line
		@@ -14,6 +14,15 @@
		#include <linux/types.h>
		#include "dccp.h"

		/*
		* Known limit values
		*/
		/* Ack Ratio takes 2-byte integer values (11.3) */
		#define DCCPF_ACK_RATIO_MAX 0xFFFF
		/* Wmin=32 and Wmax=2^46-1 from 7.5.2 */
		#define DCCPF_SEQ_WMIN 32
		#define DCCPF_SEQ_WMAX 0x3FFFFFFFFFFFull

		enum dccp_feat_type {
		FEAT_AT_RX = 1, /* located at RX side of half-connection */
		FEAT_AT_TX = 2, /* located at TX side of half-connection */
		@@ -75,6 +84,20 @@ static inline u8 dccp_feat_genopt(struct dccp_feat_entry *entry)
		return entry->is_local ? DCCPO_CHANGE_L : DCCPO_CHANGE_R;
		}

		/**
		* struct ccid_dependency - Track changes resulting from choosing a CCID
		* @dependent_feat: one of %dccp_feature_numbers
		* @is_local: local (1) or remote (0) @dependent_feat
		* @is_mandatory: whether presence of @dependent_feat is mission-critical or not
		* @val: corresponding default value for @dependent_feat (u8 is sufficient here)
		*/
		struct ccid_dependency {
		u8 dependent_feat;
		bool is_local:1,
		is_mandatory:1;
		u8 val;
		};

		#ifdef CONFIG_IP_DCCP_DEBUG
		extern const char *dccp_feat_typename(const u8 type);
		extern const char *dccp_feat_name(const u8 feat);
		@@ -97,6 +120,6 @@ extern int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
		extern void dccp_feat_clean(struct dccp_minisock *dmsk);
		extern int dccp_feat_clone(struct sock oldsk, struct sock newsk);
		extern int dccp_feat_clone_list(struct list_head const , struct list_head );
		extern int dccp_feat_init(struct dccp_minisock *dmsk);
		extern int dccp_feat_init(struct sock *sk);

		#endif /* _DCCP_FEAT_H */

net/dccp/proto.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -202,7 +202,7 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
		* setsockopt(CCIDs-I-want/accept). -acme
		*/
		if (likely(ctl_sock_initialized)) {
		int rc = dccp_feat_init(dmsk);
		int rc = dccp_feat_init(sk);

		if (rc)
		return rc;

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