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[PATCH 5/8] ipc: provide the protected payload in ipc_kmsg_copyout_heade
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From: |
Justus Winter |
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Subject: |
[PATCH 5/8] ipc: provide the protected payload in ipc_kmsg_copyout_header |
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Date: |
Thu, 18 Sep 2014 15:22:47 +0200 |
* ipc/ipc_kmsg.c (ipc_kmsg_copyout_header): If a protected payload is
set for the destination port, provide it in msgh_protected_payload.
* ipc/mach_msg.c (mach_msg_trap): Likewise in the fast paths.
* doc/mach.texi (Message Receive): Document message semantics with
protected payloads.
---
doc/mach.texi | 19 +++++++++++++++++++
ipc/ipc_kmsg.c | 58 +++++++++++++++++++++++++++++++++++++++++++++-------------
ipc/mach_msg.c | 53 ++++++++++++++++++++++++++++++++++++++++-------------
3 files changed, 104 insertions(+), 26 deletions(-)
diff --git a/doc/mach.texi b/doc/mach.texi
index b187888..c57e607 100644
--- a/doc/mach.texi
+++ b/doc/mach.texi
@@ -1949,6 +1949,25 @@ loses the receive right after the message was dequeued
from it, then
right still exists, but isn't held by the caller, then
@code{msgh_local_port} specifies @code{MACH_PORT_NULL}.
+Servers usually associate some state with a receive right. To that
+end, they might use a hash table to look up the state for the port a
+message was sent to. To optimize this, a task may associate an opaque
+@var{payload} with a receive right using the
+@code{mach_port_set_protected_payload} function. Once this is done,
+the kernel will set the @code{msgh_protected_payload} field to
+@var{payload} when delivering a message to this right and indicate
+this by setting the local part of @code{msgh_bits} to
+@code{MACH_MSG_TYPE_PROTECTED_PAYLOAD}.
+
+The support for protected payloads was added to GNU Mach. To preserve
+binary compatibility, the @code{msgh_local_port} and
+@code{msgh_local_port} share the same location. This makes it
+possible to add the payload information without increasing the size of
+@code{mach_msg_header_t}. This is an implementation detail. Which
+field is valid is determined by the local part of the
+@code{msgh_bits}. Existing software is not affected. When a receive
+right is transferred to another task, its payload is cleared.
+
Received messages are stamped with a sequence number, taken from the
port from which the message was received. (Messages received from a
port set are stamped with a sequence number from the appropriate member
diff --git a/ipc/ipc_kmsg.c b/ipc/ipc_kmsg.c
index 06cec72..71a0d74 100644
--- a/ipc/ipc_kmsg.c
+++ b/ipc/ipc_kmsg.c
@@ -1799,9 +1799,17 @@ ipc_kmsg_copyout_header(
} else
ip_unlock(dest);
- msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
- MACH_MSGH_BITS(0, MACH_MSG_TYPE_PORT_SEND));
- msg->msgh_local_port = dest_name;
+ if (! ipc_port_flag_protected_payload(dest)) {
+ msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
+ MACH_MSGH_BITS(0, MACH_MSG_TYPE_PORT_SEND));
+ msg->msgh_local_port = dest_name;
+ } else {
+ msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
+ MACH_MSGH_BITS(
+ 0, MACH_MSG_TYPE_PROTECTED_PAYLOAD));
+ msg->msgh_protected_payload =
+ dest->ip_protected_payload;
+ }
msg->msgh_remote_port = MACH_PORT_NULL;
return MACH_MSG_SUCCESS;
}
@@ -1897,10 +1905,18 @@ ipc_kmsg_copyout_header(
} else
ip_unlock(dest);
- msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
- MACH_MSGH_BITS(MACH_MSG_TYPE_PORT_SEND_ONCE,
- MACH_MSG_TYPE_PORT_SEND));
- msg->msgh_local_port = dest_name;
+ if (! ipc_port_flag_protected_payload(dest)) {
+ msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
+ MACH_MSGH_BITS(MACH_MSG_TYPE_PORT_SEND_ONCE,
+ MACH_MSG_TYPE_PORT_SEND));
+ msg->msgh_local_port = dest_name;
+ } else {
+ msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
+ MACH_MSGH_BITS(MACH_MSG_TYPE_PORT_SEND_ONCE,
+ MACH_MSG_TYPE_PROTECTED_PAYLOAD));
+ msg->msgh_protected_payload =
+ dest->ip_protected_payload;
+ }
msg->msgh_remote_port = reply_name;
return MACH_MSG_SUCCESS;
}
@@ -1932,9 +1948,18 @@ ipc_kmsg_copyout_header(
dest_name = MACH_PORT_NULL;
}
- msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
- MACH_MSGH_BITS(0, MACH_MSG_TYPE_PORT_SEND_ONCE));
- msg->msgh_local_port = dest_name;
+ if (! ipc_port_flag_protected_payload(dest)) {
+ msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
+ MACH_MSGH_BITS(0,
+ MACH_MSG_TYPE_PORT_SEND_ONCE));
+ msg->msgh_local_port = dest_name;
+ } else {
+ msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
+ MACH_MSGH_BITS(0,
+ MACH_MSG_TYPE_PROTECTED_PAYLOAD));
+ msg->msgh_protected_payload =
+ dest->ip_protected_payload;
+ }
msg->msgh_remote_port = MACH_PORT_NULL;
return MACH_MSG_SUCCESS;
}
@@ -2224,9 +2249,16 @@ ipc_kmsg_copyout_header(
if (IP_VALID(reply))
ipc_port_release(reply);
- msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
- MACH_MSGH_BITS(reply_type, dest_type));
- msg->msgh_local_port = dest_name;
+ if (! ipc_port_flag_protected_payload(dest)) {
+ msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
+ MACH_MSGH_BITS(reply_type, dest_type));
+ msg->msgh_local_port = dest_name;
+ } else {
+ msg->msgh_bits = (MACH_MSGH_BITS_OTHER(mbits) |
+ MACH_MSGH_BITS(reply_type,
+ MACH_MSG_TYPE_PROTECTED_PAYLOAD));
+ msg->msgh_protected_payload = dest->ip_protected_payload;
+ }
msg->msgh_remote_port = reply_name;
}
diff --git a/ipc/mach_msg.c b/ipc/mach_msg.c
index 01d974b..1e122c7 100644
--- a/ipc/mach_msg.c
+++ b/ipc/mach_msg.c
@@ -1132,11 +1132,19 @@ mach_msg_trap(
} else
ip_unlock(dest_port);
- kmsg->ikm_header.msgh_bits =
- MACH_MSGH_BITS(MACH_MSG_TYPE_PORT_SEND_ONCE,
- MACH_MSG_TYPE_PORT_SEND);
+ if (! ipc_port_flag_protected_payload(dest_port)) {
+ kmsg->ikm_header.msgh_bits = MACH_MSGH_BITS(
+ MACH_MSG_TYPE_PORT_SEND_ONCE,
+ MACH_MSG_TYPE_PORT_SEND);
+ kmsg->ikm_header.msgh_local_port = dest_name;
+ } else {
+ kmsg->ikm_header.msgh_bits = MACH_MSGH_BITS(
+ MACH_MSG_TYPE_PORT_SEND_ONCE,
+ MACH_MSG_TYPE_PROTECTED_PAYLOAD);
+ kmsg->ikm_header.msgh_protected_payload =
+ dest_port->ip_protected_payload;
+ }
kmsg->ikm_header.msgh_remote_port = reply_name;
- kmsg->ikm_header.msgh_local_port = dest_name;
goto fast_put;
abort_request_copyout:
@@ -1170,11 +1178,19 @@ mach_msg_trap(
dest_name = MACH_PORT_NULL;
}
- kmsg->ikm_header.msgh_bits =
- MACH_MSGH_BITS(0,
- MACH_MSG_TYPE_PORT_SEND_ONCE);
+ if (! ipc_port_flag_protected_payload(dest_port)) {
+ kmsg->ikm_header.msgh_bits = MACH_MSGH_BITS(
+ 0,
+ MACH_MSG_TYPE_PORT_SEND_ONCE);
+ kmsg->ikm_header.msgh_local_port = dest_name;
+ } else {
+ kmsg->ikm_header.msgh_bits = MACH_MSGH_BITS(
+ 0,
+ MACH_MSG_TYPE_PROTECTED_PAYLOAD);
+ kmsg->ikm_header.msgh_protected_payload =
+ dest_port->ip_protected_payload;
+ }
kmsg->ikm_header.msgh_remote_port = MACH_PORT_NULL;
- kmsg->ikm_header.msgh_local_port = dest_name;
goto fast_put;
}
@@ -1204,12 +1220,23 @@ mach_msg_trap(
dest_name = MACH_PORT_NULL;
}
- kmsg->ikm_header.msgh_bits =
- MACH_MSGH_BITS_COMPLEX |
- MACH_MSGH_BITS(0,
- MACH_MSG_TYPE_PORT_SEND_ONCE);
+ if (! ipc_port_flag_protected_payload(dest_port)) {
+ kmsg->ikm_header.msgh_bits =
+ MACH_MSGH_BITS_COMPLEX
+ | MACH_MSGH_BITS(
+ 0,
+ MACH_MSG_TYPE_PORT_SEND_ONCE);
+ kmsg->ikm_header.msgh_local_port = dest_name;
+ } else {
+ kmsg->ikm_header.msgh_bits =
+ MACH_MSGH_BITS_COMPLEX
+ | MACH_MSGH_BITS(
+ 0,
+ MACH_MSG_TYPE_PROTECTED_PAYLOAD);
+ kmsg->ikm_header.msgh_protected_payload =
+ dest_port->ip_protected_payload;
+ }
kmsg->ikm_header.msgh_remote_port = MACH_PORT_NULL;
- kmsg->ikm_header.msgh_local_port = dest_name;
mr = ipc_kmsg_copyout_body(
(vm_offset_t) (&kmsg->ikm_header + 1),
--
2.1.0
- Re: [PATCH 5/5] ipc: provide the protected payload in ipc_kmsg_copyout_header, Justus Winter, 2014/09/18
- [PATCH 1/8] ipc: add protected payload, Justus Winter, 2014/09/18
- [PATCH 2/8] ipc: implement mach_port_{set,clear}_protected_payload, Justus Winter, 2014/09/18
- [PATCH 4/8] include: define MACH_MSG_TYPE_PROTECTED_PAYLOAD, Justus Winter, 2014/09/18
- [PATCH 3/8] include: add msgh_protected_payload to mach_msg_header_t, Justus Winter, 2014/09/18
- [PATCH 5/8] ipc: provide the protected payload in ipc_kmsg_copyout_header,
Justus Winter <=
- [PATCH 6/8] include: add a payload-aware intran mutator for memory_object_t, Justus Winter, 2014/09/18
- [PATCH 7/8] include: add a payload-aware intran mutator for notify_port_t, Justus Winter, 2014/09/18
- [PATCH 8/8] include: add a payload-aware intran mutator for device_t, Justus Winter, 2014/09/18
- Re: [PATCH 1/8] ipc: add protected payload, Samuel Thibault, 2014/09/30
- Re: [PATCH 5/5] ipc: provide the protected payload in ipc_kmsg_copyout_header, Samuel Thibault, 2014/09/30