| /* |
| * net/dccp/options.c |
| * |
| * An implementation of the DCCP protocol |
| * Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org> |
| * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net> |
| * Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz> |
| * |
| * 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/dccp.h> |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/skbuff.h> |
| |
| #include "ackvec.h" |
| #include "ccid.h" |
| #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; |
| |
| void dccp_minisock_init(struct dccp_minisock *dmsk) |
| { |
| dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window; |
| dmsk->dccpms_rx_ccid = sysctl_dccp_feat_rx_ccid; |
| dmsk->dccpms_tx_ccid = sysctl_dccp_feat_tx_ccid; |
| dmsk->dccpms_ack_ratio = sysctl_dccp_feat_ack_ratio; |
| dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector; |
| dmsk->dccpms_send_ndp_count = sysctl_dccp_feat_send_ndp_count; |
| } |
| |
| static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len) |
| { |
| u32 value = 0; |
| |
| if (len > 3) |
| value += *bf++ << 24; |
| if (len > 2) |
| value += *bf++ << 16; |
| if (len > 1) |
| value += *bf++ << 8; |
| if (len > 0) |
| value += *bf; |
| |
| return value; |
| } |
| |
| int dccp_parse_options(struct sock *sk, struct sk_buff *skb) |
| { |
| 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; |
| u32 elapsed_time; |
| int rc; |
| int mandatory = 0; |
| |
| memset(opt_recv, 0, sizeof(*opt_recv)); |
| |
| opt = len = 0; |
| while (opt_ptr != opt_end) { |
| opt = *opt_ptr++; |
| len = 0; |
| value = NULL; |
| |
| /* Check if this isn't a single byte option */ |
| if (opt > DCCPO_MAX_RESERVED) { |
| if (opt_ptr == opt_end) |
| goto out_invalid_option; |
| |
| len = *opt_ptr++; |
| if (len < 3) |
| goto out_invalid_option; |
| /* |
| * Remove the type and len fields, leaving |
| * just the value size |
| */ |
| len -= 2; |
| value = opt_ptr; |
| opt_ptr += len; |
| |
| if (opt_ptr > opt_end) |
| goto out_invalid_option; |
| } |
| |
| switch (opt) { |
| case DCCPO_PADDING: |
| break; |
| case DCCPO_MANDATORY: |
| if (mandatory) |
| goto out_invalid_option; |
| if (pkt_type != DCCP_PKT_DATA) |
| mandatory = 1; |
| break; |
| case DCCPO_NDP_COUNT: |
| if (len > 3) |
| 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 (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 (len < 2) |
| goto out_invalid_option; |
| if (dccp_feat_confirm_recv(sk, opt, *value, |
| value + 1, len - 1)) |
| goto out_invalid_option; |
| break; |
| case DCCPO_ACK_VECTOR_0: |
| case DCCPO_ACK_VECTOR_1: |
| if (pkt_type == DCCP_PKT_DATA) |
| break; |
| |
| if (dccp_msk(sk)->dccpms_send_ack_vector && |
| dccp_ackvec_parse(sk, skb, &ackno, opt, value, len)) |
| goto out_invalid_option; |
| break; |
| case DCCPO_TIMESTAMP: |
| if (len != 4) |
| goto out_invalid_option; |
| |
| opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value); |
| |
| dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp; |
| dccp_timestamp(sk, &dp->dccps_timestamp_time); |
| |
| dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n", |
| dccp_role(sk), opt_recv->dccpor_timestamp, |
| (unsigned long long) |
| DCCP_SKB_CB(skb)->dccpd_ack_seq); |
| break; |
| case DCCPO_TIMESTAMP_ECHO: |
| if (len != 4 && len != 6 && len != 8) |
| goto out_invalid_option; |
| |
| opt_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value); |
| |
| dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, " |
| "ackno=%llu, ", dccp_role(sk), |
| opt_recv->dccpor_timestamp_echo, |
| len + 2, |
| (unsigned long long) |
| DCCP_SKB_CB(skb)->dccpd_ack_seq); |
| |
| |
| if (len == 4) |
| break; |
| |
| if (len == 6) |
| elapsed_time = ntohs(*(__be16 *)(value + 4)); |
| else |
| elapsed_time = ntohl(*(__be32 *)(value + 4)); |
| |
| /* Give precedence to the biggest ELAPSED_TIME */ |
| if (elapsed_time > opt_recv->dccpor_elapsed_time) |
| opt_recv->dccpor_elapsed_time = elapsed_time; |
| break; |
| case DCCPO_ELAPSED_TIME: |
| if (len != 2 && len != 4) |
| goto out_invalid_option; |
| |
| if (pkt_type == DCCP_PKT_DATA) |
| continue; |
| |
| if (len == 2) |
| elapsed_time = ntohs(*(__be16 *)value); |
| else |
| elapsed_time = ntohl(*(__be32 *)value); |
| |
| if (elapsed_time > opt_recv->dccpor_elapsed_time) |
| opt_recv->dccpor_elapsed_time = elapsed_time; |
| |
| dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n", |
| dccp_role(sk), elapsed_time); |
| break; |
| /* |
| * 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. |
| */ |
| case 128 ... 191: { |
| const u16 idx = value - options; |
| |
| if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, |
| opt, len, idx, |
| value) != 0) |
| goto out_invalid_option; |
| } |
| break; |
| case 192 ... 255: { |
| const u16 idx = value - options; |
| |
| if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, |
| opt, len, idx, |
| value) != 0) |
| goto out_invalid_option; |
| } |
| break; |
| default: |
| DCCP_CRIT("DCCP(%p): option %d(len=%d) not " |
| "implemented, ignoring", sk, opt, len); |
| break; |
| } |
| |
| if (opt != DCCPO_MANDATORY) |
| mandatory = 0; |
| } |
| |
| /* mandatory was the last byte in option list -> reset connection */ |
| if (mandatory) |
| goto out_invalid_option; |
| |
| 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); |
| return -1; |
| } |
| |
| EXPORT_SYMBOL_GPL(dccp_parse_options); |
| |
| static void dccp_encode_value_var(const u32 value, unsigned char *to, |
| const unsigned int len) |
| { |
| if (len > 3) |
| *to++ = (value & 0xFF000000) >> 24; |
| if (len > 2) |
| *to++ = (value & 0xFF0000) >> 16; |
| if (len > 1) |
| *to++ = (value & 0xFF00) >> 8; |
| if (len > 0) |
| *to++ = (value & 0xFF); |
| } |
| |
| static inline int dccp_ndp_len(const int ndp) |
| { |
| return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3; |
| } |
| |
| int dccp_insert_option(struct sock *sk, struct sk_buff *skb, |
| const unsigned char option, |
| const void *value, const unsigned char len) |
| { |
| unsigned char *to; |
| |
| if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) |
| return -1; |
| |
| DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2; |
| |
| to = skb_push(skb, len + 2); |
| *to++ = option; |
| *to++ = len + 2; |
| |
| memcpy(to, value, len); |
| return 0; |
| } |
| |
| 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; |
| |
| if (dccp_non_data_packet(skb)) |
| ++dp->dccps_ndp_count; |
| else |
| dp->dccps_ndp_count = 0; |
| |
| if (ndp > 0) { |
| unsigned char *ptr; |
| const int ndp_len = dccp_ndp_len(ndp); |
| const int len = ndp_len + 2; |
| |
| if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
| return -1; |
| |
| DCCP_SKB_CB(skb)->dccpd_opt_len += len; |
| |
| ptr = skb_push(skb, len); |
| *ptr++ = DCCPO_NDP_COUNT; |
| *ptr++ = len; |
| dccp_encode_value_var(ndp, ptr, ndp_len); |
| } |
| |
| return 0; |
| } |
| |
| 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); |
| |
| void dccp_timestamp(const struct sock *sk, struct timeval *tv) |
| { |
| const struct dccp_sock *dp = dccp_sk(sk); |
| |
| do_gettimeofday(tv); |
| tv->tv_sec -= dp->dccps_epoch.tv_sec; |
| tv->tv_usec -= dp->dccps_epoch.tv_usec; |
| |
| while (tv->tv_usec < 0) { |
| tv->tv_sec--; |
| tv->tv_usec += USEC_PER_SEC; |
| } |
| } |
| |
| EXPORT_SYMBOL_GPL(dccp_timestamp); |
| |
| int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb) |
| { |
| struct timeval tv; |
| __be32 now; |
| |
| dccp_timestamp(sk, &tv); |
| now = htonl(timeval_usecs(&tv) / 10); |
| /* 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)); |
| } |
| |
| EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp); |
| |
| static int dccp_insert_option_timestamp_echo(struct sock *sk, |
| struct sk_buff *skb) |
| { |
| struct dccp_sock *dp = dccp_sk(sk); |
| struct timeval now; |
| __be32 tstamp_echo; |
| u32 elapsed_time; |
| int len, elapsed_time_len; |
| unsigned char *to; |
| |
| dccp_timestamp(sk, &now); |
| elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10; |
| elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
| len = 6 + elapsed_time_len; |
| |
| 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_TIMESTAMP_ECHO; |
| *to++ = len; |
| |
| tstamp_echo = htonl(dp->dccps_timestamp_echo); |
| memcpy(to, &tstamp_echo, 4); |
| to += 4; |
| |
| if (elapsed_time_len == 2) { |
| const __be16 var16 = htons((u16)elapsed_time); |
| memcpy(to, &var16, 2); |
| } else if (elapsed_time_len == 4) { |
| const __be32 var32 = htonl(elapsed_time); |
| memcpy(to, &var32, 4); |
| } |
| |
| dp->dccps_timestamp_echo = 0; |
| dp->dccps_timestamp_time.tv_sec = 0; |
| dp->dccps_timestamp_time.tv_usec = 0; |
| return 0; |
| } |
| |
| static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat, |
| u8 *val, u8 len) |
| { |
| u8 *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); |
| return -1; |
| } |
| |
| DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3; |
| |
| to = skb_push(skb, len + 3); |
| *to++ = type; |
| *to++ = len + 3; |
| *to++ = feat; |
| |
| if (len) |
| memcpy(to, val, len); |
| |
| dccp_pr_debug("%s(%s (%d), ...), length %d\n", |
| dccp_feat_typename(type), |
| dccp_feat_name(feat), feat, len); |
| return 0; |
| } |
| |
| static int dccp_insert_options_feat(struct sock *sk, 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; |
| } |
| |
| /* 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++; |
| } |
| } |
| |
| /* 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); |
| |
| /* 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); |
| } |
| |
| return 0; |
| } |
| |
| 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)) |
| 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)) |
| return -1; |
| |
| if (dp->dccps_timestamp_echo != 0 && |
| dccp_insert_option_timestamp_echo(sk, skb)) |
| return -1; |
| } |
| |
| if (dp->dccps_hc_rx_insert_options) { |
| if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb)) |
| return -1; |
| 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; |
| |
| /* XXX: insert other options when appropriate */ |
| |
| if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) { |
| /* The length of all options has to be a multiple of 4 */ |
| int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4; |
| |
| if (padding != 0) { |
| padding = 4 - padding; |
| memset(skb_push(skb, padding), 0, padding); |
| DCCP_SKB_CB(skb)->dccpd_opt_len += padding; |
| } |
| } |
| |
| return 0; |
| } |