git: e96f9fa135a2 - stable/13 - bhyve/snapshot: use SOCK_DGRAM instead of SOCK_STREAM
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Date: Thu, 26 Jan 2023 18:54:20 UTC
The branch stable/13 has been updated by jhb:
URL: https://cgit.FreeBSD.org/src/commit/?id=e96f9fa135a24befbc7ea611f38848d83bff9a4d
commit e96f9fa135a24befbc7ea611f38848d83bff9a4d
Author: Robert Wing <rew@FreeBSD.org>
AuthorDate: 2021-03-08 00:23:29 +0000
Commit: John Baldwin <jhb@FreeBSD.org>
CommitDate: 2023-01-26 18:46:01 +0000
bhyve/snapshot: use SOCK_DGRAM instead of SOCK_STREAM
The save/restore feature uses a unix domain socket to send messages
from bhyvectl(8) to a bhyve(8) process. A datagram socket will suffice
for this.
An added benefit of using a datagram socket is simplified code. For
bhyve, the listen/accept calls are dropped; and for bhyvectl, the
connect() call is dropped.
EPRINTLN handles raw mode for bhyve(8), use it to print error messages.
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D28983
(cherry picked from commit 38dfb0626fd35c64b2e2d5faae2c90e7981a3307)
---
usr.sbin/bhyve/snapshot.c | 65 +++++++++++++++++---------------------------
usr.sbin/bhyvectl/bhyvectl.c | 22 ++++-----------
2 files changed, 31 insertions(+), 56 deletions(-)
diff --git a/usr.sbin/bhyve/snapshot.c b/usr.sbin/bhyve/snapshot.c
index 2938a0e84c88..061ba11096e9 100644
--- a/usr.sbin/bhyve/snapshot.c
+++ b/usr.sbin/bhyve/snapshot.c
@@ -79,6 +79,7 @@ __FBSDID("$FreeBSD$");
#include "bhyverun.h"
#include "acpi.h"
#include "atkbdc.h"
+#include "debug.h"
#include "inout.h"
#include "fwctl.h"
#include "ioapic.h"
@@ -117,8 +118,6 @@ static sig_t old_winch_handler;
#define MAX_VMNAME 100
-#define MAX_MSG_SIZE 1024
-
#define SNAPSHOT_BUFFER_SIZE (20 * MB)
#define JSON_STRUCT_ARR_KEY "structs"
@@ -1442,24 +1441,10 @@ done:
}
int
-get_checkpoint_msg(int conn_fd, struct vmctx *ctx)
+handle_message(struct checkpoint_op *checkpoint_op, struct vmctx *ctx)
{
- unsigned char buf[MAX_MSG_SIZE];
- struct checkpoint_op *checkpoint_op;
- int len, recv_len, total_recv = 0;
- int err = 0;
-
- len = sizeof(struct checkpoint_op); /* expected length */
- while ((recv_len = recv(conn_fd, buf + total_recv, len - total_recv, 0)) > 0) {
- total_recv += recv_len;
- }
- if (recv_len < 0) {
- perror("Error while receiving data from bhyvectl");
- err = -1;
- goto done;
- }
+ int err;
- checkpoint_op = (struct checkpoint_op *)buf;
switch (checkpoint_op->op) {
case START_CHECKPOINT:
err = vm_checkpoint(ctx, checkpoint_op->snapshot_filename, false);
@@ -1468,12 +1453,13 @@ get_checkpoint_msg(int conn_fd, struct vmctx *ctx)
err = vm_checkpoint(ctx, checkpoint_op->snapshot_filename, true);
break;
default:
- fprintf(stderr, "Unrecognized checkpoint operation.\n");
+ EPRINTLN("Unrecognized checkpoint operation\n");
err = -1;
}
-done:
- close(conn_fd);
+ if (err != 0)
+ EPRINTLN("Unable to perform the requested operation\n");
+
return (err);
}
@@ -1483,21 +1469,25 @@ done:
void *
checkpoint_thread(void *param)
{
+ struct checkpoint_op op;
struct checkpoint_thread_info *thread_info;
- int conn_fd, ret;
+ ssize_t n;
pthread_set_name_np(pthread_self(), "checkpoint thread");
thread_info = (struct checkpoint_thread_info *)param;
- while ((conn_fd = accept(thread_info->socket_fd, NULL, NULL)) > -1) {
- ret = get_checkpoint_msg(conn_fd, thread_info->ctx);
- if (ret != 0) {
- fprintf(stderr, "Failed to read message on checkpoint "
- "socket. Retrying.\n");
- }
- }
- if (conn_fd < -1) {
- perror("Failed to accept connection");
+ for (;;) {
+ n = recvfrom(thread_info->socket_fd, &op, sizeof(op), 0, NULL, 0);
+
+ /*
+ * slight sanity check: see if there's enough data to at
+ * least determine the type of message.
+ */
+ if (n >= sizeof(op.op))
+ handle_message(&op, thread_info->ctx);
+ else
+ EPRINTLN("Failed to receive message: %s\n",
+ n == -1 ? strerror(errno) : "unknown error");
}
return (NULL);
@@ -1527,9 +1517,9 @@ init_checkpoint_thread(struct vmctx *ctx)
if (err != 0)
errc(1, err, "checkpoint cv init");
- socket_fd = socket(PF_UNIX, SOCK_STREAM, 0);
+ socket_fd = socket(PF_UNIX, SOCK_DGRAM, 0);
if (socket_fd < 0) {
- perror("Socket creation failed (IPC with bhyvectl");
+ EPRINTLN("Socket creation failed: %s", strerror(errno));
err = -1;
goto fail;
}
@@ -1548,13 +1538,8 @@ init_checkpoint_thread(struct vmctx *ctx)
unlink(addr.sun_path);
if (bind(socket_fd, (struct sockaddr *)&addr, addr.sun_len) != 0) {
- perror("Failed to bind socket (IPC with bhyvectl)");
- err = -1;
- goto fail;
- }
-
- if (listen(socket_fd, 10) < 0) {
- perror("Failed to listen on socket (IPC with bhyvectl)");
+ EPRINTLN("Failed to bind socket \"%s\": %s\n",
+ addr.sun_path, strerror(errno));
err = -1;
goto fail;
}
diff --git a/usr.sbin/bhyvectl/bhyvectl.c b/usr.sbin/bhyvectl/bhyvectl.c
index 0f7b9533fe4b..df02f7caf345 100644
--- a/usr.sbin/bhyvectl/bhyvectl.c
+++ b/usr.sbin/bhyvectl/bhyvectl.c
@@ -1687,11 +1687,11 @@ static int
send_checkpoint_op_req(struct vmctx *ctx, struct checkpoint_op *op)
{
struct sockaddr_un addr;
- int socket_fd, len, len_sent, total_sent;
- int err = 0;
+ ssize_t len_sent;
+ int err, socket_fd;
char vmname_buf[MAX_VMNAME];
- socket_fd = socket(PF_UNIX, SOCK_STREAM, 0);
+ socket_fd = socket(PF_UNIX, SOCK_DGRAM, 0);
if (socket_fd < 0) {
perror("Error creating bhyvectl socket");
err = -1;
@@ -1709,21 +1709,11 @@ send_checkpoint_op_req(struct vmctx *ctx, struct checkpoint_op *op)
snprintf(addr.sun_path, sizeof(addr.sun_path), "%s%s", BHYVE_RUN_DIR, vmname_buf);
- if (connect(socket_fd, (struct sockaddr *)&addr,
- sizeof(struct sockaddr_un)) != 0) {
- perror("Connect to VM socket failed");
- err = -1;
- goto done;
- }
-
- len = sizeof(*op);
- total_sent = 0;
- while ((len_sent = send(socket_fd, (char *)op + total_sent, len - total_sent, 0)) > 0) {
- total_sent += len_sent;
- }
+ len_sent = sendto(socket_fd, op, sizeof(*op), 0,
+ (struct sockaddr *)&addr, sizeof(struct sockaddr_un));
if (len_sent < 0) {
- perror("Failed to send checkpoint operation request");
+ perror("Failed to send message to bhyve vm");
err = -1;
}