is present). Connecting sockets set at most one service option; for
listening sockets, multiple service codes can be specified.
+DCCP_SOCKOPT_SEND_CSCOV and DCCP_SOCKOPT_RECV_CSCOV are used for setting the
+partial checksum coverage (RFC 4340, sec. 9.2). The default is that checksums
+always cover the entire packet and that only fully covered application data is
+accepted by the receiver. Hence, when using this feature on the sender, it must
+be enabled at the receiver, too with suitable choice of CsCov.
+
+DCCP_SOCKOPT_SEND_CSCOV sets the sender checksum coverage. Values in the
+ range 0..15 are acceptable. The default setting is 0 (full coverage),
+ values between 1..15 indicate partial coverage.
+DCCP_SOCKOPT_SEND_CSCOV is for the receiver and has a different meaning: it
+ sets a threshold, where again values 0..15 are acceptable. The default
+ of 0 means that all packets with a partial coverage will be discarded.
+ Values in the range 1..15 indicate that packets with minimally such a
+ coverage value are also acceptable. The higher the number, the more
+ restrictive this setting (see [RFC 4340, sec. 9.2.1]).
+
Notes
=====
DCCPF_ACK_RATIO = 5,
DCCPF_SEND_ACK_VECTOR = 6,
DCCPF_SEND_NDP_COUNT = 7,
+ DCCPF_MIN_CSUM_COVER = 8,
/* 10-127 reserved */
DCCPF_MIN_CCID_SPECIFIC = 128,
DCCPF_MAX_CCID_SPECIFIC = 255,
#define DCCP_SOCKOPT_SERVICE 2
#define DCCP_SOCKOPT_CHANGE_L 3
#define DCCP_SOCKOPT_CHANGE_R 4
+#define DCCP_SOCKOPT_SEND_CSCOV 10
+#define DCCP_SOCKOPT_RECV_CSCOV 11
#define DCCP_SOCKOPT_CCID_RX_INFO 128
#define DCCP_SOCKOPT_CCID_TX_INFO 192
* @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
* @dccps_packet_size - Set thru setsockopt
* @dccps_role - Role of this sock, one of %dccp_role
+ * @dccps_pcslen - sender partial checksum coverage (via sockopt)
+ * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
* @dccps_ndp_count - number of Non Data Packets since last data packet
* @dccps_hc_rx_ackvec - rx half connection ack vector
* @dccps_xmit_timer - timer for when CCID is not ready to send
__u32 dccps_packet_size;
__u16 dccps_l_ack_ratio;
__u16 dccps_r_ack_ratio;
+ __u16 dccps_pcslen;
+ __u16 dccps_pcrlen;
unsigned long dccps_ndp_count;
__u32 dccps_mss_cache;
struct dccp_minisock dccps_minisock;
#define DCCP_ADD_STATS_USER(field, val) \
SNMP_ADD_STATS_USER(dccp_statistics, field, val)
+/*
+ * Checksumming routines
+ */
+static inline int dccp_csum_coverage(const struct sk_buff *skb)
+{
+ const struct dccp_hdr* dh = dccp_hdr(skb);
+
+ if (dh->dccph_cscov == 0)
+ return skb->len;
+ return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
+}
+
+static inline void dccp_csum_outgoing(struct sk_buff *skb)
+{
+ int cov = dccp_csum_coverage(skb);
+
+ if (cov >= skb->len)
+ dccp_hdr(skb)->dccph_cscov = 0;
+
+ skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
+}
+
+extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
+
extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
extern void dccp_send_ack(struct sock *sk);
extern int inet_dccp_listen(struct socket *sock, int backlog);
extern unsigned int dccp_poll(struct file *file, struct socket *sock,
poll_table *wait);
-extern void dccp_v4_send_check(struct sock *sk, int len,
- struct sk_buff *skb);
extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
int addr_len);
-extern int dccp_v4_checksum(const struct sk_buff *skb,
- const __be32 saddr, const __be32 daddr);
-
extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
extern void dccp_send_close(struct sock *sk, const int active);
extern int dccp_invalid_packet(struct sk_buff *skb);
sock_put(sk);
}
-/* This routine computes an IPv4 DCCP checksum. */
-void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
+static inline u16 dccp_v4_csum_finish(struct sk_buff *skb,
+ __be32 src, __be32 dst)
+{
+ return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
+}
+
+void dccp_v4_send_check(struct sock *sk, int unused, struct sk_buff *skb)
{
const struct inet_sock *inet = inet_sk(sk);
struct dccp_hdr *dh = dccp_hdr(skb);
- dh->dccph_checksum = dccp_v4_checksum(skb, inet->saddr, inet->daddr);
+ dccp_csum_outgoing(skb);
+ dh->dccph_checksum = dccp_v4_csum_finish(skb, inet->saddr, inet->daddr);
}
EXPORT_SYMBOL_GPL(dccp_v4_send_check);
return sk;
}
-int dccp_v4_checksum(const struct sk_buff *skb, const __be32 saddr,
- const __be32 daddr)
-{
- const struct dccp_hdr* dh = dccp_hdr(skb);
- int checksum_len;
- u32 tmp;
-
- if (dh->dccph_cscov == 0)
- checksum_len = skb->len;
- else {
- checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
- checksum_len = checksum_len < skb->len ? checksum_len :
- skb->len;
- }
-
- tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
- return csum_tcpudp_magic(saddr, daddr, checksum_len,
- IPPROTO_DCCP, tmp);
-}
-
-EXPORT_SYMBOL_GPL(dccp_v4_checksum);
-
-static int dccp_v4_verify_checksum(struct sk_buff *skb,
- const __be32 saddr, const __be32 daddr)
-{
- struct dccp_hdr *dh = dccp_hdr(skb);
- int checksum_len;
- u32 tmp;
-
- if (dh->dccph_cscov == 0)
- checksum_len = skb->len;
- else {
- checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
- checksum_len = checksum_len < skb->len ? checksum_len :
- skb->len;
- }
- tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
- return csum_tcpudp_magic(saddr, daddr, checksum_len,
- IPPROTO_DCCP, tmp) == 0 ? 0 : -1;
-}
-
static struct dst_entry* dccp_v4_route_skb(struct sock *sk,
struct sk_buff *skb)
{
const struct inet_request_sock *ireq = inet_rsk(req);
struct dccp_hdr *dh = dccp_hdr(skb);
- dh->dccph_checksum = dccp_v4_checksum(skb, ireq->loc_addr,
- ireq->rmt_addr);
+ dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
+ ireq->rmt_addr);
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
ireq->rmt_addr,
dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
DCCP_SKB_CB(rxskb)->dccpd_seq);
- dh->dccph_checksum = dccp_v4_checksum(skb, rxskb->nh.iph->saddr,
- rxskb->nh.iph->daddr);
+ dccp_csum_outgoing(skb);
+ dh->dccph_checksum = dccp_v4_csum_finish(skb, rxskb->nh.iph->saddr,
+ rxskb->nh.iph->daddr);
bh_lock_sock(dccp_v4_ctl_socket->sk);
err = ip_build_and_send_pkt(skb, dccp_v4_ctl_socket->sk,
int dccp_invalid_packet(struct sk_buff *skb)
{
const struct dccp_hdr *dh;
+ unsigned int cscov;
if (skb->pkt_type != PACKET_HOST)
return 1;
return 1;
}
+ /*
+ * If P.CsCov is too large for the packet size, drop packet and return.
+ * This must come _before_ checksumming (not as RFC 4340 suggests).
+ */
+ cscov = dccp_csum_coverage(skb);
+ if (cscov > skb->len) {
+ LIMIT_NETDEBUG(KERN_WARNING
+ "DCCP: P.CsCov %u exceeds packet length %d\n",
+ dh->dccph_cscov, skb->len);
+ return 1;
+ }
+
+ /* If header checksum is incorrect, drop packet and return.
+ * (This step is completed in the AF-dependent functions.) */
+ skb->csum = skb_checksum(skb, 0, cscov, 0);
+
return 0;
}
{
const struct dccp_hdr *dh;
struct sock *sk;
+ int min_cov;
- /* Step 1: Check header basics: */
+ /* Step 1: Check header basics */
if (dccp_invalid_packet(skb))
goto discard_it;
- /* If the header checksum is incorrect, drop packet and return */
- if (dccp_v4_verify_checksum(skb, skb->nh.iph->saddr,
- skb->nh.iph->daddr) < 0) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: incorrect header checksum\n",
+ /* Step 1: If header checksum is incorrect, drop packet and return */
+ if (dccp_v4_csum_finish(skb, skb->nh.iph->saddr, skb->nh.iph->daddr)) {
+ LIMIT_NETDEBUG(KERN_WARNING
+ "%s: dropped packet with invalid checksum\n",
__FUNCTION__);
goto discard_it;
}
goto no_dccp_socket;
}
+ /*
+ * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
+ * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
+ * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
+ */
+ min_cov = dccp_sk(sk)->dccps_pcrlen;
+ if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
+ dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
+ dh->dccph_cscov, min_cov);
+ /* FIXME: "Such packets SHOULD be reported using Data Dropped
+ * options (Section 11.7) with Drop Code 0, Protocol
+ * Constraints." */
+ goto discard_and_relse;
+ }
+
if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
goto discard_and_relse;
nf_reset(skb);
}
}
-static inline u16 dccp_v6_check(struct dccp_hdr *dh, int len,
- struct in6_addr *saddr,
- struct in6_addr *daddr,
- unsigned long base)
+/* add pseudo-header to DCCP checksum stored in skb->csum */
+static inline u16 dccp_v6_csum_finish(struct sk_buff *skb,
+ struct in6_addr *saddr,
+ struct in6_addr *daddr)
{
- return csum_ipv6_magic(saddr, daddr, len, IPPROTO_DCCP, base);
+ return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
+}
+
+static inline void dccp_v6_send_check(struct sock *sk, int unused_value,
+ struct sk_buff *skb)
+{
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct dccp_hdr *dh = dccp_hdr(skb);
+
+ dccp_csum_outgoing(skb);
+ dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &np->daddr);
}
static __u32 dccp_v6_init_sequence(struct sock *sk, struct sk_buff *skb)
if (skb != NULL) {
struct dccp_hdr *dh = dccp_hdr(skb);
- dh->dccph_checksum = dccp_v6_check(dh, skb->len,
- &ireq6->loc_addr,
- &ireq6->rmt_addr,
- csum_partial((char *)dh,
- skb->len,
- skb->csum));
+ dh->dccph_checksum = dccp_v6_csum_finish(skb,
+ &ireq6->loc_addr,
+ &ireq6->rmt_addr);
ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
err = ip6_xmit(sk, skb, &fl, opt, 0);
if (err == NET_XMIT_CN)
kfree_skb(inet6_rsk(req)->pktopts);
}
-static void dccp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
-{
- struct ipv6_pinfo *np = inet6_sk(sk);
- struct dccp_hdr *dh = dccp_hdr(skb);
-
- dh->dccph_checksum = csum_ipv6_magic(&np->saddr, &np->daddr,
- len, IPPROTO_DCCP,
- csum_partial((char *)dh,
- dh->dccph_doff << 2,
- skb->csum));
-}
-
static void dccp_v6_ctl_send_reset(struct sk_buff *rxskb)
{
struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
DCCP_SKB_CB(rxskb)->dccpd_seq);
+ dccp_csum_outgoing(skb);
+ dh->dccph_checksum = dccp_v6_csum_finish(skb, &rxskb->nh.ipv6h->saddr,
+ &rxskb->nh.ipv6h->daddr);
+
memset(&fl, 0, sizeof(fl));
ipv6_addr_copy(&fl.fl6_dst, &rxskb->nh.ipv6h->saddr);
ipv6_addr_copy(&fl.fl6_src, &rxskb->nh.ipv6h->daddr);
- dh->dccph_checksum = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
- sizeof(*dh), IPPROTO_DCCP,
- skb->csum);
+
fl.proto = IPPROTO_DCCP;
fl.oif = inet6_iif(rxskb);
fl.fl_ip_dport = dh->dccph_dport;
const struct dccp_hdr *dh;
struct sk_buff *skb = *pskb;
struct sock *sk;
+ int min_cov;
- /* Step 1: Check header basics: */
+ /* Step 1: Check header basics */
if (dccp_invalid_packet(skb))
goto discard_it;
+ /* Step 1: If header checksum is incorrect, drop packet and return. */
+ if (dccp_v6_csum_finish(skb, &skb->nh.ipv6h->saddr,
+ &skb->nh.ipv6h->daddr)) {
+ LIMIT_NETDEBUG(KERN_WARNING
+ "%s: dropped packet with invalid checksum\n",
+ __FUNCTION__);
+ goto discard_it;
+ }
+
dh = dccp_hdr(skb);
DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(skb);
goto no_dccp_socket;
}
+ /*
+ * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
+ * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
+ * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
+ */
+ min_cov = dccp_sk(sk)->dccps_pcrlen;
+ if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
+ dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
+ dh->dccph_cscov, min_cov);
+ /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
+ goto discard_and_relse;
+ }
+
if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
goto discard_and_relse;
dh->dccph_dport = inet->dport;
dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4;
dh->dccph_ccval = dcb->dccpd_ccval;
+ dh->dccph_cscov = dp->dccps_pcslen;
/* XXX For now we're using only 48 bits sequence numbers */
dh->dccph_x = 1;
break;
}
- icsk->icsk_af_ops->send_check(sk, skb->len, skb);
+ icsk->icsk_af_ops->send_check(sk, 0, skb);
if (set_ack)
dccp_event_ack_sent(sk);
skb_reserve(skb, sk->sk_prot->max_header);
skb->dst = dst_clone(dst);
- skb->csum = 0;
dreq = dccp_rsk(req);
DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr);
dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service;
+ dccp_csum_outgoing(skb);
+
DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
return skb;
}
skb_reserve(skb, sk->sk_prot->max_header);
skb->dst = dst_clone(dst);
- skb->csum = 0;
dccp_inc_seqno(&dp->dccps_gss);
dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr);
dccp_hdr_reset(skb)->dccph_reset_code = code;
- inet_csk(sk)->icsk_af_ops->send_check(sk, skb->len, skb);
+ inet_csk(sk)->icsk_af_ops->send_check(sk, 0, skb);
DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
return skb;
skb_reserve(skb, sk->sk_prot->max_header);
DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST;
- skb->csum = 0;
dccp_skb_entail(sk, skb);
dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL));
/* Reserve space for headers */
skb_reserve(skb, sk->sk_prot->max_header);
- skb->csum = 0;
DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK;
dccp_transmit_skb(sk, skb);
}
/* Reserve space for headers and prepare control bits. */
skb_reserve(skb, sk->sk_prot->max_header);
- skb->csum = 0;
DCCP_SKB_CB(skb)->dccpd_type = pkt_type;
DCCP_SKB_CB(skb)->dccpd_seq = seq;
/* Reserve space for headers and prepare control bits. */
skb_reserve(skb, sk->sk_prot->max_header);
- skb->csum = 0;
DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ?
DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ;
case DCCP_SOCKOPT_PACKET_SIZE:
dp->dccps_packet_size = val;
break;
-
case DCCP_SOCKOPT_CHANGE_L:
if (optlen != sizeof(struct dccp_so_feat))
err = -EINVAL;
(struct dccp_so_feat __user *)
optval);
break;
-
case DCCP_SOCKOPT_CHANGE_R:
if (optlen != sizeof(struct dccp_so_feat))
err = -EINVAL;
(struct dccp_so_feat __user *)
optval);
break;
-
+ case DCCP_SOCKOPT_SEND_CSCOV: /* sender side, RFC 4340, sec. 9.2 */
+ if (val < 0 || val > 15)
+ err = -EINVAL;
+ else
+ dp->dccps_pcslen = val;
+ break;
+ case DCCP_SOCKOPT_RECV_CSCOV: /* receiver side, RFC 4340 sec. 9.2.1 */
+ if (val < 0 || val > 15)
+ err = -EINVAL;
+ else {
+ dp->dccps_pcrlen = val;
+ /* FIXME: add feature negotiation,
+ * ChangeL(MinimumChecksumCoverage, val) */
+ }
+ break;
default:
err = -ENOPROTOOPT;
break;
}
-
+
release_sock(sk);
return err;
}
case DCCP_SOCKOPT_SERVICE:
return dccp_getsockopt_service(sk, len,
(__be32 __user *)optval, optlen);
+ case DCCP_SOCKOPT_SEND_CSCOV:
+ val = dp->dccps_pcslen;
+ break;
+ case DCCP_SOCKOPT_RECV_CSCOV:
+ val = dp->dccps_pcrlen;
+ break;
case 128 ... 191:
return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
len, (u32 __user *)optval, optlen);
projects / linux-flexiantxendom0-natty.git / commitdiff