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-rw-r--r--net/mptcp/options.c229
-rw-r--r--net/mptcp/protocol.h1
2 files changed, 121 insertions, 109 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 4c37f4b215ee..1a59b3045a33 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -592,6 +592,7 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb,
dss_size = map_size;
if (skb && snd_data_fin_enable)
mptcp_write_data_fin(subflow, skb, &opts->ext_copy);
+ opts->suboptions = OPTION_MPTCP_DSS;
ret = true;
}
@@ -615,6 +616,7 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb,
opts->ext_copy.ack64 = 0;
}
opts->ext_copy.use_ack = 1;
+ opts->suboptions = OPTION_MPTCP_DSS;
WRITE_ONCE(msk->old_wspace, __mptcp_space((struct sock *)msk));
/* Add kind/length/subtype/flag overhead if mapping is not populated */
@@ -686,8 +688,13 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff *
if (drop_other_suboptions) {
pr_debug("drop other suboptions");
opts->suboptions = 0;
- opts->ext_copy.use_ack = 0;
- opts->ext_copy.use_map = 0;
+
+ /* note that e.g. DSS could have written into the memory
+ * aliased by ahmac, we must reset the field here
+ * to avoid appending the hmac even for ADD_ADDR echo
+ * options
+ */
+ opts->ahmac = 0;
*size -= opt_size;
}
opts->suboptions |= OPTION_MPTCP_ADD_ADDR;
@@ -739,7 +746,12 @@ static bool mptcp_established_options_mp_prio(struct sock *sk,
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
- if (!subflow->send_mp_prio)
+ /* can't send MP_PRIO with MPC, as they share the same option space:
+ * 'backup'. Also it makes no sense at all
+ */
+ if (!subflow->send_mp_prio ||
+ ((OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK |
+ OPTION_MPTCP_MPC_ACK) & opts->suboptions))
return false;
/* account for the trailing 'nop' option */
@@ -1198,8 +1210,74 @@ static u16 mptcp_make_csum(const struct mptcp_ext *mpext)
void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
struct mptcp_out_options *opts)
{
- if ((OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK |
- OPTION_MPTCP_MPC_ACK) & opts->suboptions) {
+ /* RST is mutually exclusive with everything else */
+ if (unlikely(OPTION_MPTCP_RST & opts->suboptions)) {
+ *ptr++ = mptcp_option(MPTCPOPT_RST,
+ TCPOLEN_MPTCP_RST,
+ opts->reset_transient,
+ opts->reset_reason);
+ return;
+ }
+
+ /* DSS, MPC, MPJ and ADD_ADDR are mutually exclusive, see
+ * mptcp_established_options*()
+ */
+ if (likely(OPTION_MPTCP_DSS & opts->suboptions)) {
+ struct mptcp_ext *mpext = &opts->ext_copy;
+ u8 len = TCPOLEN_MPTCP_DSS_BASE;
+ u8 flags = 0;
+
+ if (mpext->use_ack) {
+ flags = MPTCP_DSS_HAS_ACK;
+ if (mpext->ack64) {
+ len += TCPOLEN_MPTCP_DSS_ACK64;
+ flags |= MPTCP_DSS_ACK64;
+ } else {
+ len += TCPOLEN_MPTCP_DSS_ACK32;
+ }
+ }
+
+ if (mpext->use_map) {
+ len += TCPOLEN_MPTCP_DSS_MAP64;
+
+ /* Use only 64-bit mapping flags for now, add
+ * support for optional 32-bit mappings later.
+ */
+ flags |= MPTCP_DSS_HAS_MAP | MPTCP_DSS_DSN64;
+ if (mpext->data_fin)
+ flags |= MPTCP_DSS_DATA_FIN;
+
+ if (opts->csum_reqd)
+ len += TCPOLEN_MPTCP_DSS_CHECKSUM;
+ }
+
+ *ptr++ = mptcp_option(MPTCPOPT_DSS, len, 0, flags);
+
+ if (mpext->use_ack) {
+ if (mpext->ack64) {
+ put_unaligned_be64(mpext->data_ack, ptr);
+ ptr += 2;
+ } else {
+ put_unaligned_be32(mpext->data_ack32, ptr);
+ ptr += 1;
+ }
+ }
+
+ if (mpext->use_map) {
+ put_unaligned_be64(mpext->data_seq, ptr);
+ ptr += 2;
+ put_unaligned_be32(mpext->subflow_seq, ptr);
+ ptr += 1;
+ if (opts->csum_reqd) {
+ put_unaligned_be32(mpext->data_len << 16 |
+ mptcp_make_csum(mpext), ptr);
+ } else {
+ put_unaligned_be32(mpext->data_len << 16 |
+ TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
+ }
+ }
+ } else if ((OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK |
+ OPTION_MPTCP_MPC_ACK) & opts->suboptions) {
u8 len, flag = MPTCP_CAP_HMAC_SHA256;
if (OPTION_MPTCP_MPC_SYN & opts->suboptions) {
@@ -1246,10 +1324,31 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
}
ptr += 1;
- }
-mp_capable_done:
- if (OPTION_MPTCP_ADD_ADDR & opts->suboptions) {
+ /* MPC is additionally mutually exclusive with MP_PRIO */
+ goto mp_capable_done;
+ } else if (OPTION_MPTCP_MPJ_SYN & opts->suboptions) {
+ *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
+ TCPOLEN_MPTCP_MPJ_SYN,
+ opts->backup, opts->join_id);
+ put_unaligned_be32(opts->token, ptr);
+ ptr += 1;
+ put_unaligned_be32(opts->nonce, ptr);
+ ptr += 1;
+ } else if (OPTION_MPTCP_MPJ_SYNACK & opts->suboptions) {
+ *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
+ TCPOLEN_MPTCP_MPJ_SYNACK,
+ opts->backup, opts->join_id);
+ put_unaligned_be64(opts->thmac, ptr);
+ ptr += 2;
+ put_unaligned_be32(opts->nonce, ptr);
+ ptr += 1;
+ } else if (OPTION_MPTCP_MPJ_ACK & opts->suboptions) {
+ *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
+ TCPOLEN_MPTCP_MPJ_ACK, 0, 0);
+ memcpy(ptr, opts->hmac, MPTCPOPT_HMAC_LEN);
+ ptr += 5;
+ } else if (OPTION_MPTCP_ADD_ADDR & opts->suboptions) {
u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
u8 echo = MPTCP_ADDR_ECHO;
@@ -1307,6 +1406,19 @@ mp_capable_done:
}
}
+ if (OPTION_MPTCP_PRIO & opts->suboptions) {
+ const struct sock *ssk = (const struct sock *)tp;
+ struct mptcp_subflow_context *subflow;
+
+ subflow = mptcp_subflow_ctx(ssk);
+ subflow->send_mp_prio = 0;
+
+ *ptr++ = mptcp_option(MPTCPOPT_MP_PRIO,
+ TCPOLEN_MPTCP_PRIO,
+ opts->backup, TCPOPT_NOP);
+ }
+
+mp_capable_done:
if (OPTION_MPTCP_RM_ADDR & opts->suboptions) {
u8 i = 1;
@@ -1327,107 +1439,6 @@ mp_capable_done:
}
}
- if (OPTION_MPTCP_PRIO & opts->suboptions) {
- const struct sock *ssk = (const struct sock *)tp;
- struct mptcp_subflow_context *subflow;
-
- subflow = mptcp_subflow_ctx(ssk);
- subflow->send_mp_prio = 0;
-
- *ptr++ = mptcp_option(MPTCPOPT_MP_PRIO,
- TCPOLEN_MPTCP_PRIO,
- opts->backup, TCPOPT_NOP);
- }
-
- if (OPTION_MPTCP_MPJ_SYN & opts->suboptions) {
- *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
- TCPOLEN_MPTCP_MPJ_SYN,
- opts->backup, opts->join_id);
- put_unaligned_be32(opts->token, ptr);
- ptr += 1;
- put_unaligned_be32(opts->nonce, ptr);
- ptr += 1;
- }
-
- if (OPTION_MPTCP_MPJ_SYNACK & opts->suboptions) {
- *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
- TCPOLEN_MPTCP_MPJ_SYNACK,
- opts->backup, opts->join_id);
- put_unaligned_be64(opts->thmac, ptr);
- ptr += 2;
- put_unaligned_be32(opts->nonce, ptr);
- ptr += 1;
- }
-
- if (OPTION_MPTCP_MPJ_ACK & opts->suboptions) {
- *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
- TCPOLEN_MPTCP_MPJ_ACK, 0, 0);
- memcpy(ptr, opts->hmac, MPTCPOPT_HMAC_LEN);
- ptr += 5;
- }
-
- if (OPTION_MPTCP_RST & opts->suboptions)
- *ptr++ = mptcp_option(MPTCPOPT_RST,
- TCPOLEN_MPTCP_RST,
- opts->reset_transient,
- opts->reset_reason);
-
- if (opts->ext_copy.use_ack || opts->ext_copy.use_map) {
- struct mptcp_ext *mpext = &opts->ext_copy;
- u8 len = TCPOLEN_MPTCP_DSS_BASE;
- u8 flags = 0;
-
- if (mpext->use_ack) {
- flags = MPTCP_DSS_HAS_ACK;
- if (mpext->ack64) {
- len += TCPOLEN_MPTCP_DSS_ACK64;
- flags |= MPTCP_DSS_ACK64;
- } else {
- len += TCPOLEN_MPTCP_DSS_ACK32;
- }
- }
-
- if (mpext->use_map) {
- len += TCPOLEN_MPTCP_DSS_MAP64;
-
- /* Use only 64-bit mapping flags for now, add
- * support for optional 32-bit mappings later.
- */
- flags |= MPTCP_DSS_HAS_MAP | MPTCP_DSS_DSN64;
- if (mpext->data_fin)
- flags |= MPTCP_DSS_DATA_FIN;
-
- if (opts->csum_reqd)
- len += TCPOLEN_MPTCP_DSS_CHECKSUM;
- }
-
- *ptr++ = mptcp_option(MPTCPOPT_DSS, len, 0, flags);
-
- if (mpext->use_ack) {
- if (mpext->ack64) {
- put_unaligned_be64(mpext->data_ack, ptr);
- ptr += 2;
- } else {
- put_unaligned_be32(mpext->data_ack32, ptr);
- ptr += 1;
- }
- }
-
- if (mpext->use_map) {
- put_unaligned_be64(mpext->data_seq, ptr);
- ptr += 2;
- put_unaligned_be32(mpext->subflow_seq, ptr);
- ptr += 1;
- if (opts->csum_reqd) {
- put_unaligned_be32(mpext->data_len << 16 |
- mptcp_make_csum(mpext), ptr);
- } else {
- put_unaligned_be32(mpext->data_len << 16 |
- TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
- }
- }
- }
-
if (tp)
mptcp_set_rwin(tp);
}
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 7cd3d5979bcd..d276ce16f126 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -26,6 +26,7 @@
#define OPTION_MPTCP_FASTCLOSE BIT(8)
#define OPTION_MPTCP_PRIO BIT(9)
#define OPTION_MPTCP_RST BIT(10)
+#define OPTION_MPTCP_DSS BIT(11)
/* MPTCP option subtypes */
#define MPTCPOPT_MP_CAPABLE 0
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.