[PATCH net-next 17/17] rxrpc: Ask the security class how much space to allow in a packet
David Howells
dhowells at redhat.com
Mon Nov 23 15:12:02 EST 2020
Ask the security class how much header and trailer space to allow for when
allocating a packet, given how much data is remaining.
This will allow the rxgk security class to stick both a trailer in as well
as a header as appropriate in the future.
Signed-off-by: David Howells <dhowells at redhat.com>
---
net/rxrpc/ar-internal.h | 7 ++++-
net/rxrpc/conn_object.c | 1 -
net/rxrpc/insecure.c | 12 +++++++++
net/rxrpc/rxkad.c | 61 ++++++++++++++++++++++++++++++++++++++++-------
net/rxrpc/sendmsg.c | 41 ++++++++++----------------------
5 files changed, 82 insertions(+), 40 deletions(-)
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index fda6618df1cc..7bd6f8a66a3e 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -234,6 +234,11 @@ struct rxrpc_security {
int (*init_connection_security)(struct rxrpc_connection *,
struct rxrpc_key_token *);
+ /* Work out how much data we can store in a packet, given an estimate
+ * of the amount of data remaining.
+ */
+ int (*how_much_data)(struct rxrpc_call *, size_t,
+ size_t *, size_t *, size_t *);
/* impose security on a packet */
int (*secure_packet)(struct rxrpc_call *, struct sk_buff *, size_t);
@@ -467,8 +472,6 @@ struct rxrpc_connection {
atomic_t serial; /* packet serial number counter */
unsigned int hi_serial; /* highest serial number received */
u32 service_id; /* Service ID, possibly upgraded */
- u8 size_align; /* data size alignment (for security) */
- u8 security_size; /* security header size */
u8 security_ix; /* security type */
u8 out_clientflag; /* RXRPC_CLIENT_INITIATED if we are client */
u8 bundle_shift; /* Index into bundle->avail_chans */
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
index 8dd1ef25b98f..b2159dbf5412 100644
--- a/net/rxrpc/conn_object.c
+++ b/net/rxrpc/conn_object.c
@@ -49,7 +49,6 @@ struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
conn->security = &rxrpc_no_security;
spin_lock_init(&conn->state_lock);
conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
- conn->size_align = 4;
conn->idle_timestamp = jiffies;
}
diff --git a/net/rxrpc/insecure.c b/net/rxrpc/insecure.c
index e06725e21c05..9aae99d67833 100644
--- a/net/rxrpc/insecure.c
+++ b/net/rxrpc/insecure.c
@@ -14,6 +14,17 @@ static int none_init_connection_security(struct rxrpc_connection *conn,
return 0;
}
+/*
+ * Work out how much data we can put in an unsecured packet.
+ */
+static int none_how_much_data(struct rxrpc_call *call, size_t remain,
+ size_t *_buf_size, size_t *_data_size, size_t *_offset)
+{
+ *_buf_size = *_data_size = min_t(size_t, remain, RXRPC_JUMBO_DATALEN);
+ *_offset = 0;
+ return 0;
+}
+
static int none_secure_packet(struct rxrpc_call *call, struct sk_buff *skb,
size_t data_size)
{
@@ -81,6 +92,7 @@ const struct rxrpc_security rxrpc_no_security = {
.exit = none_exit,
.init_connection_security = none_init_connection_security,
.free_call_crypto = none_free_call_crypto,
+ .how_much_data = none_how_much_data,
.secure_packet = none_secure_packet,
.verify_packet = none_verify_packet,
.locate_data = none_locate_data,
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index e5b4bbdd0f34..e2e9e9b0a6d7 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -28,6 +28,7 @@
#define INST_SZ 40 /* size of principal's instance */
#define REALM_SZ 40 /* size of principal's auth domain */
#define SNAME_SZ 40 /* size of service name */
+#define RXKAD_ALIGN 8
struct rxkad_level1_hdr {
__be32 data_size; /* true data size (excluding padding) */
@@ -80,7 +81,7 @@ static int rxkad_preparse_server_key(struct key_preparsed_payload *prep)
static void rxkad_free_preparse_server_key(struct key_preparsed_payload *prep)
{
-
+
if (prep->payload.data[0])
crypto_free_skcipher(prep->payload.data[0]);
}
@@ -119,14 +120,8 @@ static int rxkad_init_connection_security(struct rxrpc_connection *conn,
switch (conn->params.security_level) {
case RXRPC_SECURITY_PLAIN:
- break;
case RXRPC_SECURITY_AUTH:
- conn->size_align = 8;
- conn->security_size = sizeof(struct rxkad_level1_hdr);
- break;
case RXRPC_SECURITY_ENCRYPT:
- conn->size_align = 8;
- conn->security_size = sizeof(struct rxkad_level2_hdr);
break;
default:
ret = -EKEYREJECTED;
@@ -147,6 +142,40 @@ static int rxkad_init_connection_security(struct rxrpc_connection *conn,
return ret;
}
+/*
+ * Work out how much data we can put in a packet.
+ */
+static int rxkad_how_much_data(struct rxrpc_call *call, size_t remain,
+ size_t *_buf_size, size_t *_data_size, size_t *_offset)
+{
+ size_t shdr, buf_size, chunk;
+
+ switch (call->conn->params.security_level) {
+ default:
+ buf_size = chunk = min_t(size_t, remain, RXRPC_JUMBO_DATALEN);
+ shdr = 0;
+ goto out;
+ case RXRPC_SECURITY_AUTH:
+ shdr = sizeof(struct rxkad_level1_hdr);
+ break;
+ case RXRPC_SECURITY_ENCRYPT:
+ shdr = sizeof(struct rxkad_level2_hdr);
+ break;
+ }
+
+ buf_size = round_down(RXRPC_JUMBO_DATALEN, RXKAD_ALIGN);
+
+ chunk = buf_size - shdr;
+ if (remain < chunk)
+ buf_size = round_up(shdr + remain, RXKAD_ALIGN);
+
+out:
+ *_buf_size = buf_size;
+ *_data_size = chunk;
+ *_offset = shdr;
+ return 0;
+}
+
/*
* prime the encryption state with the invariant parts of a connection's
* description
@@ -237,6 +266,7 @@ static int rxkad_secure_packet_auth(const struct rxrpc_call *call,
struct rxkad_level1_hdr hdr;
struct rxrpc_crypt iv;
struct scatterlist sg;
+ size_t pad;
u16 check;
_enter("");
@@ -247,6 +277,12 @@ static int rxkad_secure_packet_auth(const struct rxrpc_call *call,
hdr.data_size = htonl(data_size);
memcpy(skb->head, &hdr, sizeof(hdr));
+ pad = sizeof(struct rxkad_level1_hdr) + data_size;
+ pad = RXKAD_ALIGN - pad;
+ pad &= RXKAD_ALIGN - 1;
+ if (pad)
+ skb_put_zero(skb, pad);
+
/* start the encryption afresh */
memset(&iv, 0, sizeof(iv));
@@ -275,6 +311,7 @@ static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
struct rxrpc_crypt iv;
struct scatterlist sg[16];
unsigned int len;
+ size_t pad;
u16 check;
int err;
@@ -288,6 +325,12 @@ static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
rxkhdr.checksum = 0;
memcpy(skb->head, &rxkhdr, sizeof(rxkhdr));
+ pad = sizeof(struct rxkad_level2_hdr) + data_size;
+ pad = RXKAD_ALIGN - pad;
+ pad &= RXKAD_ALIGN - 1;
+ if (pad)
+ skb_put_zero(skb, pad);
+
/* encrypt from the session key */
token = call->conn->params.key->payload.data[0];
memcpy(&iv, token->kad->session_key, sizeof(iv));
@@ -303,8 +346,7 @@ static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
if (skb_shinfo(skb)->nr_frags > 16)
goto out;
- len = data_size + call->conn->size_align - 1;
- len &= ~(call->conn->size_align - 1);
+ len = round_up(data_size, RXKAD_ALIGN);
sg_init_table(sg, ARRAY_SIZE(sg));
err = skb_to_sgvec(skb, sg, 8, len);
@@ -1353,6 +1395,7 @@ const struct rxrpc_security rxkad = {
.free_preparse_server_key = rxkad_free_preparse_server_key,
.destroy_server_key = rxkad_destroy_server_key,
.init_connection_security = rxkad_init_connection_security,
+ .how_much_data = rxkad_how_much_data,
.secure_packet = rxkad_secure_packet,
.verify_packet = rxkad_verify_packet,
.free_call_crypto = rxkad_free_call_crypto,
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 367654a558c2..af8ad6c30b9f 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -327,7 +327,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
rxrpc_send_ack_packet(call, false, NULL);
if (!skb) {
- size_t size, chunk, max, space;
+ size_t remain, bufsize, chunk, offset;
_debug("alloc");
@@ -342,24 +342,21 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
goto maybe_error;
}
- max = RXRPC_JUMBO_DATALEN;
- max -= call->conn->security_size;
- max &= ~(call->conn->size_align - 1UL);
-
- chunk = max;
- if (chunk > msg_data_left(msg) && !more)
- chunk = msg_data_left(msg);
-
- space = chunk + call->conn->size_align;
- space &= ~(call->conn->size_align - 1UL);
-
- size = space + call->conn->security_size;
+ /* Work out the maximum size of a packet. Assume that
+ * the security header is going to be in the padded
+ * region (enc blocksize), but the trailer is not.
+ */
+ remain = more ? INT_MAX : msg_data_left(msg);
+ ret = call->conn->security->how_much_data(call, remain,
+ &bufsize, &chunk, &offset);
+ if (ret < 0)
+ goto maybe_error;
- _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
+ _debug("SIZE: %zu/%zu @%zu", chunk, bufsize, offset);
/* create a buffer that we can retain until it's ACK'd */
skb = sock_alloc_send_skb(
- sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
+ sk, bufsize, msg->msg_flags & MSG_DONTWAIT, &ret);
if (!skb)
goto maybe_error;
@@ -371,8 +368,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
ASSERTCMP(skb->mark, ==, 0);
- _debug("HS: %u", call->conn->security_size);
- __skb_put(skb, call->conn->security_size);
+ __skb_put(skb, offset);
sp->remain = chunk;
if (sp->remain > skb_tailroom(skb))
@@ -421,17 +417,6 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
(msg_data_left(msg) == 0 && !more)) {
struct rxrpc_connection *conn = call->conn;
uint32_t seq;
- size_t pad;
-
- /* pad out if we're using security */
- if (conn->security_ix) {
- pad = conn->security_size + skb->mark;
- pad = conn->size_align - pad;
- pad &= conn->size_align - 1;
- _debug("pad %zu", pad);
- if (pad)
- skb_put_zero(skb, pad);
- }
seq = call->tx_top + 1;
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