diff options
| -rw-r--r-- | net/dccp/ccids/ccid2.c | 6 | ||||
| -rw-r--r-- | net/dccp/feat.c | 192 | ||||
| -rw-r--r-- | net/dccp/feat.h | 25 | ||||
| -rw-r--r-- | net/dccp/proto.c | 2 |
4 files changed, 197 insertions, 28 deletions
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c index 9a43073..c9ea19a 100644 --- a/net/dccp/ccids/ccid2.c +++ b/net/dccp/ccids/ccid2.c @@ -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; diff --git a/net/dccp/feat.c b/net/dccp/feat.c index 0e789e2..192d494 100644 --- a/net/dccp/feat.c +++ b/net/dccp/feat.c @@ -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, - &dmsk->dccpms_tx_ccid, 1); + 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, - &dmsk->dccpms_rx_ccid, 1); + 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; } diff --git a/net/dccp/feat.h b/net/dccp/feat.h index f5e99b3..232c653 100644 --- a/net/dccp/feat.h +++ b/net/dccp/feat.h @@ -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 */ diff --git a/net/dccp/proto.c b/net/dccp/proto.c index dafcefd..01332fe 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -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; |
