diff options
Diffstat (limited to 'net/dccp/options.c')
| -rw-r--r-- | net/dccp/options.c | 420 |
1 files changed, 208 insertions, 212 deletions
diff --git a/net/dccp/options.c b/net/dccp/options.c index d2a84a2fece..9bce31886bd 100644 --- a/net/dccp/options.c +++ b/net/dccp/options.c @@ -23,23 +23,20 @@ #include "dccp.h" #include "feat.h" -int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW; -int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID; -int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID; -int sysctl_dccp_feat_ack_ratio = DCCPF_INITIAL_ACK_RATIO; -int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR; -int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT; - -static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len) +u64 dccp_decode_value_var(const u8 *bf, const u8 len) { - u32 value = 0; + u64 value = 0; + if (len >= DCCP_OPTVAL_MAXLEN) + value += ((u64)*bf++) << 40; + if (len > 4) + value += ((u64)*bf++) << 32; if (len > 3) - value += *bf++ << 24; + value += ((u64)*bf++) << 24; if (len > 2) - value += *bf++ << 16; + value += ((u64)*bf++) << 16; if (len > 1) - value += *bf++ << 8; + value += ((u64)*bf++) << 8; if (len > 0) value += *bf; @@ -57,14 +54,13 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, struct dccp_sock *dp = dccp_sk(sk); const struct dccp_hdr *dh = dccp_hdr(skb); const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type; - u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); unsigned char *opt_ptr = options; const unsigned char *opt_end = (unsigned char *)dh + (dh->dccph_doff * 4); struct dccp_options_received *opt_recv = &dp->dccps_options_received; unsigned char opt, len; - unsigned char *value; + unsigned char *uninitialized_var(value); u32 elapsed_time; __be32 opt_val; int rc; @@ -81,11 +77,11 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, /* Check if this isn't a single byte option */ if (opt > DCCPO_MAX_RESERVED) { if (opt_ptr == opt_end) - goto out_invalid_option; + goto out_nonsensical_length; len = *opt_ptr++; - if (len < 3) - goto out_invalid_option; + if (len < 2) + goto out_nonsensical_length; /* * Remove the type and len fields, leaving * just the value size @@ -95,21 +91,16 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, opt_ptr += len; if (opt_ptr > opt_end) - goto out_invalid_option; + goto out_nonsensical_length; } /* - * CCID-Specific Options (from RFC 4340, sec. 10.3): - * - * Option numbers 128 through 191 are for options sent from the - * HC-Sender to the HC-Receiver; option numbers 192 through 255 - * are for options sent from the HC-Receiver to the HC-Sender. - * * CCID-specific options are ignored during connection setup, as * negotiation may still be in progress (see RFC 4340, 10.3). - * + * The same applies to Ack Vectors, as these depend on the CCID. */ - if (dreq != NULL && opt >= 128) + if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC || + opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1)) goto ignore_option; switch (opt) { @@ -122,50 +113,22 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, mandatory = 1; break; case DCCPO_NDP_COUNT: - if (len > 3) + if (len > 6) goto out_invalid_option; opt_recv->dccpor_ndp = dccp_decode_value_var(value, len); - dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk), - opt_recv->dccpor_ndp); - break; - case DCCPO_CHANGE_L: - /* fall through */ - case DCCPO_CHANGE_R: - if (pkt_type == DCCP_PKT_DATA) - break; - if (len < 2) - goto out_invalid_option; - rc = dccp_feat_change_recv(sk, opt, *value, value + 1, - len - 1); - /* - * When there is a change error, change_recv is - * responsible for dealing with it. i.e. reply with an - * empty confirm. - * If the change was mandatory, then we need to die. - */ - if (rc && mandatory) - goto out_invalid_option; - break; - case DCCPO_CONFIRM_L: - /* fall through */ - case DCCPO_CONFIRM_R: - if (pkt_type == DCCP_PKT_DATA) - break; - if (len < 2) /* FIXME this disallows empty confirm */ - goto out_invalid_option; - if (dccp_feat_confirm_recv(sk, opt, *value, - value + 1, len - 1)) - goto out_invalid_option; + dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk), + (unsigned long long)opt_recv->dccpor_ndp); break; - case DCCPO_ACK_VECTOR_0: - case DCCPO_ACK_VECTOR_1: - if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */ + case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R: + if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */ break; - - if (dccp_msk(sk)->dccpms_send_ack_vector && - dccp_ackvec_parse(sk, skb, &ackno, opt, value, len)) + if (len == 0) goto out_invalid_option; + rc = dccp_feat_parse_options(sk, dreq, mandatory, opt, + *value, value + 1, len - 1); + if (rc) + goto out_featneg_failed; break; case DCCPO_TIMESTAMP: if (len != 4) @@ -193,6 +156,8 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, dccp_role(sk), ntohl(opt_val), (unsigned long long) DCCP_SKB_CB(skb)->dccpd_ack_seq); + /* schedule an Ack in case this sender is quiescent */ + inet_csk_schedule_ack(sk); break; case DCCPO_TIMESTAMP_ECHO: if (len != 4 && len != 6 && len != 8) @@ -249,23 +214,25 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n", dccp_role(sk), elapsed_time); break; - case 128 ... 191: { - const u16 idx = value - options; - + case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC: if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, - opt, len, idx, - value) != 0) + pkt_type, opt, value, len)) goto out_invalid_option; - } break; - case 192 ... 255: { - const u16 idx = value - options; - + case DCCPO_ACK_VECTOR_0: + case DCCPO_ACK_VECTOR_1: + if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */ + break; + /* + * Ack vectors are processed by the TX CCID if it is + * interested. The RX CCID need not parse Ack Vectors, + * since it is only interested in clearing old state. + * Fall through. + */ + case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC: if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, - opt, len, idx, - value) != 0) + pkt_type, opt, value, len)) goto out_invalid_option; - } break; default: DCCP_CRIT("DCCP(%p): option %d(len=%d) not " @@ -281,20 +248,30 @@ ignore_option: if (mandatory) goto out_invalid_option; +out_nonsensical_length: + /* RFC 4340, 5.8: ignore option and all remaining option space */ return 0; out_invalid_option: DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT); - DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR; - DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len); + rc = DCCP_RESET_CODE_OPTION_ERROR; +out_featneg_failed: + DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc); + DCCP_SKB_CB(skb)->dccpd_reset_code = rc; + DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt; + DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0; + DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0; return -1; } EXPORT_SYMBOL_GPL(dccp_parse_options); -static void dccp_encode_value_var(const u32 value, unsigned char *to, - const unsigned int len) +void dccp_encode_value_var(const u64 value, u8 *to, const u8 len) { + if (len >= DCCP_OPTVAL_MAXLEN) + *to++ = (value & 0xFF0000000000ull) >> 40; + if (len > 4) + *to++ = (value & 0xFF00000000ull) >> 32; if (len > 3) *to++ = (value & 0xFF000000) >> 24; if (len > 2) @@ -305,14 +282,15 @@ static void dccp_encode_value_var(const u32 value, unsigned char *to, *to++ = (value & 0xFF); } -static inline int dccp_ndp_len(const int ndp) +static inline u8 dccp_ndp_len(const u64 ndp) { - return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3; + if (likely(ndp <= 0xFF)) + return 1; + return likely(ndp <= USHRT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6); } -int dccp_insert_option(struct sock *sk, struct sk_buff *skb, - const unsigned char option, - const void *value, const unsigned char len) +int dccp_insert_option(struct sk_buff *skb, const unsigned char option, + const void *value, const unsigned char len) { unsigned char *to; @@ -334,7 +312,7 @@ EXPORT_SYMBOL_GPL(dccp_insert_option); static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); - int ndp = dp->dccps_ndp_count; + u64 ndp = dp->dccps_ndp_count; if (dccp_non_data_packet(skb)) ++dp->dccps_ndp_count; @@ -365,49 +343,15 @@ static inline int dccp_elapsed_time_len(const u32 elapsed_time) return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4; } -int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb, - u32 elapsed_time) -{ - const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time); - const int len = 2 + elapsed_time_len; - unsigned char *to; - - if (elapsed_time_len == 0) - return 0; - - if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) - return -1; - - DCCP_SKB_CB(skb)->dccpd_opt_len += len; - - to = skb_push(skb, len); - *to++ = DCCPO_ELAPSED_TIME; - *to++ = len; - - if (elapsed_time_len == 2) { - const __be16 var16 = htons((u16)elapsed_time); - memcpy(to, &var16, 2); - } else { - const __be32 var32 = htonl(elapsed_time); - memcpy(to, &var32, 4); - } - - return 0; -} - -EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time); - -int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb) +static int dccp_insert_option_timestamp(struct sk_buff *skb) { __be32 now = htonl(dccp_timestamp()); /* yes this will overflow but that is the point as we want a * 10 usec 32 bit timer which mean it wraps every 11.9 hours */ - return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now)); + return dccp_insert_option(skb, DCCPO_TIMESTAMP, &now, sizeof(now)); } -EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp); - static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp, struct dccp_request_sock *dreq, struct sk_buff *skb) @@ -452,92 +396,141 @@ static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp, return 0; } -static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat, - u8 *val, u8 len) +static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) { - u8 *to; + struct dccp_sock *dp = dccp_sk(sk); + struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec; + struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); + const u16 buflen = dccp_ackvec_buflen(av); + /* Figure out how many options do we need to represent the ackvec */ + const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN); + u16 len = buflen + 2 * nr_opts; + u8 i, nonce = 0; + const unsigned char *tail, *from; + unsigned char *to; - if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) { - DCCP_WARN("packet too small for feature %d option!\n", feat); + if (dcb->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { + DCCP_WARN("Lacking space for %u bytes on %s packet\n", len, + dccp_packet_name(dcb->dccpd_type)); return -1; } + /* + * Since Ack Vectors are variable-length, we can not always predict + * their size. To catch exception cases where the space is running out + * on the skb, a separate Sync is scheduled to carry the Ack Vector. + */ + if (len > DCCPAV_MIN_OPTLEN && + len + dcb->dccpd_opt_len + skb->len > dp->dccps_mss_cache) { + DCCP_WARN("No space left for Ack Vector (%u) on skb (%u+%u), " + "MPS=%u ==> reduce payload size?\n", len, skb->len, + dcb->dccpd_opt_len, dp->dccps_mss_cache); + dp->dccps_sync_scheduled = 1; + return 0; + } + dcb->dccpd_opt_len += len; - DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3; + to = skb_push(skb, len); + len = buflen; + from = av->av_buf + av->av_buf_head; + tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN; - to = skb_push(skb, len + 3); - *to++ = type; - *to++ = len + 3; - *to++ = feat; + for (i = 0; i < nr_opts; ++i) { + int copylen = len; - if (len) - memcpy(to, val, len); + if (len > DCCP_SINGLE_OPT_MAXLEN) + copylen = DCCP_SINGLE_OPT_MAXLEN; - dccp_pr_debug("%s(%s (%d), ...), length %d\n", - dccp_feat_typename(type), - dccp_feat_name(feat), feat, len); + /* + * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via + * its type; ack_nonce is the sum of all individual buf_nonce's. + */ + nonce ^= av->av_buf_nonce[i]; + + *to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i]; + *to++ = copylen + 2; + + /* Check if buf_head wraps */ + if (from + copylen > tail) { + const u16 tailsize = tail - from; + + memcpy(to, from, tailsize); + to += tailsize; + len -= tailsize; + copylen -= tailsize; + from = av->av_buf; + } + + memcpy(to, from, copylen); + from += copylen; + to += copylen; + len -= copylen; + } + /* + * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340. + */ + if (dccp_ackvec_update_records(av, dcb->dccpd_seq, nonce)) + return -ENOBUFS; return 0; } -static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb) +/** + * dccp_insert_option_mandatory - Mandatory option (5.8.2) + * Note that since we are using skb_push, this function needs to be called + * _after_ inserting the option it is supposed to influence (stack order). + */ +int dccp_insert_option_mandatory(struct sk_buff *skb) { - struct dccp_sock *dp = dccp_sk(sk); - struct dccp_minisock *dmsk = dccp_msk(sk); - struct dccp_opt_pend *opt, *next; - int change = 0; - - /* confirm any options [NN opts] */ - list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) { - dccp_insert_feat_opt(skb, opt->dccpop_type, - opt->dccpop_feat, opt->dccpop_val, - opt->dccpop_len); - /* fear empty confirms */ - if (opt->dccpop_val) - kfree(opt->dccpop_val); - kfree(opt); - } - INIT_LIST_HEAD(&dmsk->dccpms_conf); - - /* see which features we need to send */ - list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) { - /* see if we need to send any confirm */ - if (opt->dccpop_sc) { - dccp_insert_feat_opt(skb, opt->dccpop_type + 1, - opt->dccpop_feat, - opt->dccpop_sc->dccpoc_val, - opt->dccpop_sc->dccpoc_len); - - BUG_ON(!opt->dccpop_sc->dccpoc_val); - kfree(opt->dccpop_sc->dccpoc_val); - kfree(opt->dccpop_sc); - opt->dccpop_sc = NULL; - } + if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN) + return -1; - /* any option not confirmed, re-send it */ - if (!opt->dccpop_conf) { - dccp_insert_feat_opt(skb, opt->dccpop_type, - opt->dccpop_feat, opt->dccpop_val, - opt->dccpop_len); - change++; - } + DCCP_SKB_CB(skb)->dccpd_opt_len++; + *skb_push(skb, 1) = DCCPO_MANDATORY; + return 0; +} + +/** + * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb + * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R + * @feat: one out of %dccp_feature_numbers + * @val: NN value or SP array (preferred element first) to copy + * @len: true length of @val in bytes (excluding first element repetition) + * @repeat_first: whether to copy the first element of @val twice + * + * The last argument is used to construct Confirm options, where the preferred + * value and the preference list appear separately (RFC 4340, 6.3.1). Preference + * lists are kept such that the preferred entry is always first, so we only need + * to copy twice, and avoid the overhead of cloning into a bigger array. + */ +int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, + u8 *val, u8 len, bool repeat_first) +{ + u8 tot_len, *to; + + /* take the `Feature' field and possible repetition into account */ + if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) { + DCCP_WARN("length %u for feature %u too large\n", len, feat); + return -1; } - /* Retransmit timer. - * If this is the master listening sock, we don't set a timer on it. It - * should be fine because if the dude doesn't receive our RESPONSE - * [which will contain the CHANGE] he will send another REQUEST which - * will "retrnasmit" the change. - */ - if (change && dp->dccps_role != DCCP_ROLE_LISTEN) { - dccp_pr_debug("reset feat negotiation timer %p\n", sk); + if (unlikely(val == NULL || len == 0)) + len = repeat_first = false; + tot_len = 3 + repeat_first + len; - /* XXX don't reset the timer on re-transmissions. I.e. reset it - * only when sending new stuff i guess. Currently the timer - * never backs off because on re-transmission it just resets it! - */ - inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, - inet_csk(sk)->icsk_rto, DCCP_RTO_MAX); + if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) { + DCCP_WARN("packet too small for feature %d option!\n", feat); + return -1; } + DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len; + to = skb_push(skb, tot_len); + *to++ = type; + *to++ = tot_len; + *to++ = feat; + + if (repeat_first) + *to++ = *val; + if (len) + memcpy(to, val, len); return 0; } @@ -556,19 +549,30 @@ static void dccp_insert_option_padding(struct sk_buff *skb) int dccp_insert_options(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); - struct dccp_minisock *dmsk = dccp_msk(sk); DCCP_SKB_CB(skb)->dccpd_opt_len = 0; - if (dmsk->dccpms_send_ndp_count && - dccp_insert_option_ndp(sk, skb)) + if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb)) return -1; - if (!dccp_packet_without_ack(skb)) { - if (dmsk->dccpms_send_ack_vector && - dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) && - dccp_insert_option_ackvec(sk, skb)) + if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) { + + /* Feature Negotiation */ + if (dccp_feat_insert_opts(dp, NULL, skb)) return -1; + + if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) { + /* + * Obtain RTT sample from Request/Response exchange. + * This is currently used for TFRC initialisation. + */ + if (dccp_insert_option_timestamp(skb)) + return -1; + + } else if (dccp_ackvec_pending(sk) && + dccp_insert_option_ackvec(sk, skb)) { + return -1; + } } if (dp->dccps_hc_rx_insert_options) { @@ -577,21 +581,6 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb) dp->dccps_hc_rx_insert_options = 0; } - /* Feature negotiation */ - /* Data packets can't do feat negotiation */ - if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA && - DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK && - dccp_insert_options_feat(sk, skb)) - return -1; - - /* - * Obtain RTT sample from Request/Response exchange. - * This is currently used in CCID 3 initialisation. - */ - if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST && - dccp_insert_option_timestamp(sk, skb)) - return -1; - if (dp->dccps_timestamp_echo != 0 && dccp_insert_option_timestamp_echo(dp, NULL, skb)) return -1; @@ -604,6 +593,13 @@ int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb) { DCCP_SKB_CB(skb)->dccpd_opt_len = 0; + if (dccp_feat_insert_opts(NULL, dreq, skb)) + return -1; + + /* Obtain RTT sample from Response/Ack exchange (used by TFRC). */ + if (dccp_insert_option_timestamp(skb)) + return -1; + if (dreq->dreq_timestamp_echo != 0 && dccp_insert_option_timestamp_echo(NULL, dreq, skb)) return -1; |
