diff mbox series

[PATCH-for-5.0,v2,3/4] qga: Extract qmp_guest_file_read() to common commands.c

Message ID 20200331140638.16464-4-philmd@redhat.com
State New
Headers show
Series qga: Restrict guest-file-read count to 10 MB to avoid crashes | expand

Commit Message

Philippe Mathieu-Daudé March 31, 2020, 2:06 p.m. UTC 
Extract the common code shared by both POSIX/Win32 implementations.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 qga/commands-common.h |  3 +++
 qga/commands-posix.c  | 22 +++-------------------
 qga/commands-win32.c  | 20 +++-----------------
 qga/commands.c        | 25 +++++++++++++++++++++++++
 4 files changed, 34 insertions(+), 36 deletions(-)
diff mbox series

Patch

diff --git a/qga/commands-common.h b/qga/commands-common.h
index af90e5481e..90785ed4bb 100644
--- a/qga/commands-common.h
+++ b/qga/commands-common.h
@@ -15,4 +15,7 @@  typedef struct GuestFileHandle GuestFileHandle;
 
 GuestFileHandle *guest_file_handle_find(int64_t id, Error **errp);
 
+GuestFileRead *guest_file_read_unsafe(GuestFileHandle *gfh,
+                                      int64_t count, Error **errp);
+
 #endif
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 2199b3b6d9..3352e9ca66 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -461,29 +461,14 @@  void qmp_guest_file_close(int64_t handle, Error **errp)
     g_free(gfh);
 }
 
-struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
-                                          int64_t count, Error **errp)
+GuestFileRead *guest_file_read_unsafe(GuestFileHandle *gfh,
+                                      int64_t count, Error **errp)
 {
-    GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
     GuestFileRead *read_data = NULL;
     guchar *buf;
-    FILE *fh;
+    FILE *fh = gfh->fh;
     size_t read_count;
 
-    if (!gfh) {
-        return NULL;
-    }
-
-    if (!has_count) {
-        count = QGA_READ_COUNT_DEFAULT;
-    } else if (count < 0 || count >= UINT32_MAX) {
-        error_setg(errp, "value '%" PRId64 "' is invalid for argument count",
-                   count);
-        return NULL;
-    }
-
-    fh = gfh->fh;
-
     /* explicitly flush when switching from writing to reading */
     if (gfh->state == RW_STATE_WRITING) {
         int ret = fflush(fh);
@@ -498,7 +483,6 @@  struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
     read_count = fread(buf, 1, count, fh);
     if (ferror(fh)) {
         error_setg_errno(errp, errno, "failed to read file");
-        slog("guest-file-read failed, handle: %" PRId64, handle);
     } else {
         buf[read_count] = 0;
         read_data = g_new0(GuestFileRead, 1);
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index cfaf6b84b8..9717a8d52d 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -322,33 +322,19 @@  void qmp_guest_shutdown(bool has_mode, const char *mode, Error **errp)
     }
 }
 
-GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
-                                   int64_t count, Error **errp)
+GuestFileRead *guest_file_read_unsafe(GuestFileHandle *gfh,
+                                      int64_t count, Error **errp)
 {
     GuestFileRead *read_data = NULL;
     guchar *buf;
-    HANDLE fh;
+    HANDLE fh = gfh->fh;
     bool is_ok;
     DWORD read_count;
-    GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
 
-    if (!gfh) {
-        return NULL;
-    }
-    if (!has_count) {
-        count = QGA_READ_COUNT_DEFAULT;
-    } else if (count < 0 || count >= UINT32_MAX) {
-        error_setg(errp, "value '%" PRId64
-                   "' is invalid for argument count", count);
-        return NULL;
-    }
-
-    fh = gfh->fh;
     buf = g_malloc0(count + 1);
     is_ok = ReadFile(fh, buf, count, &read_count, NULL);
     if (!is_ok) {
         error_setg_win32(errp, GetLastError(), "failed to read file");
-        slog("guest-file-read failed, handle %" PRId64, handle);
     } else {
         buf[read_count] = 0;
         read_data = g_new0(GuestFileRead, 1);
diff --git a/qga/commands.c b/qga/commands.c
index 4471a9f08d..8ee1244ebb 100644
--- a/qga/commands.c
+++ b/qga/commands.c
@@ -547,3 +547,28 @@  error:
     g_free(info);
     return NULL;
 }
+
+GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
+                                   int64_t count, Error **errp)
+{
+    GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
+    GuestFileRead *read_data;
+
+    if (!gfh) {
+        return NULL;
+    }
+    if (!has_count) {
+        count = QGA_READ_COUNT_DEFAULT;
+    } else if (count < 0 || count >= UINT32_MAX) {
+        error_setg(errp, "value '%" PRId64 "' is invalid for argument count",
+                   count);
+        return NULL;
+    }
+
+    read_data = guest_file_read_unsafe(gfh, count, errp);
+    if (!read_data) {
+        slog("guest-file-write failed, handle: %" PRId64, handle);
+    }
+
+    return read_data;
+}