qemu: unescape HMP commands before converting them to json

QMP commands don't need to be escaped since converting them to json also escapes special characters. When a QMP command fails, however, libvirt falls back to HMP commands. These fallback functions (qemuMonitorText*) do their own escaping, and pass the result directly to qemuMonitorHMPCommandWithFd. If the monitor is in json mode, these pre-escaped commands will be escaped again when converted to json, which can result in the wrong arguments being sent. For example, a filename test\file would be sent in json as test\\file. This prevented attaching an image file with a " or \ in its name in qemu 1.0.50, and also broke rbd attachment (which uses backslashes to escape some internal arguments.) Reported-by: Masuko Tomoya <tomoya.masuko@gmail.com> Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2026-08-14 07:04:43 -05:00 · 2012-02-27 16:06:02 -07:00
parent 4716138229
commit f27f616ff8
5 changed files with 192 additions and 7 deletions
@@ -0,0 +1,118 @@
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifdef WITH_QEMU
+
+# include "internal.h"
+# include "memory.h"
+# include "testutils.h"
+# include "util.h"
+# include "qemu/qemu_monitor.h"
+
+struct testEscapeString
+{
+    const char *unescaped;
+    const char *escaped;
+};
+
+static struct testEscapeString escapeStrings[] = {
+    { "", "" },
+    { " ", " " },
+    { "\\", "\\\\" },
+    { "\n", "\\n" },
+    { "\r", "\\r" },
+    { "\"", "\\\"" },
+    { "\"\"\"\\\\\n\r\\\\\n\r\"\"\"", "\\\"\\\"\\\"\\\\\\\\\\n\\r\\\\\\\\\\n\\r\\\"\\\"\\\"" },
+    { "drive_add dummy file=foo\\", "drive_add dummy file=foo\\\\" },
+    { "block info", "block info" },
+    { "set_password \":\\\"\"", "set_password \\\":\\\\\\\"\\\"" },
+};
+
+static int testEscapeArg(const void *data ATTRIBUTE_UNUSED)
+{
+    int i;
+    char *escaped = NULL;
+    for (i = 0; i < ARRAY_CARDINALITY(escapeStrings); ++i) {
+        escaped = qemuMonitorEscapeArg(escapeStrings[i].unescaped);
+        if (!escaped) {
+            if (virTestGetDebug() > 0) {
+                fprintf(stderr, "\nUnescaped string [%s]\n",
+                        escapeStrings[i].unescaped);
+                fprintf(stderr, "Expect result [%s]\n",
+                        escapeStrings[i].escaped);
+                fprintf(stderr, "Actual result [(null)]\n");
+            }
+            return -1;
+        }
+        if (STRNEQ(escapeStrings[i].escaped, escaped)) {
+            virtTestDifference(stderr, escapeStrings[i].escaped, escaped);
+            VIR_FREE(escaped);
+            return -1;
+        }
+        VIR_FREE(escaped);
+    }
+
+    return 0;
+}
+
+static int testUnescapeArg(const void *data ATTRIBUTE_UNUSED)
+{
+    int i;
+    char *unescaped = NULL;
+    for (i = 0; i < ARRAY_CARDINALITY(escapeStrings); ++i) {
+        unescaped = qemuMonitorUnescapeArg(escapeStrings[i].escaped);
+        if (!unescaped) {
+            if (virTestGetDebug() > 0) {
+                fprintf(stderr, "\nEscaped string [%s]\n",
+                        escapeStrings[i].escaped);
+                fprintf(stderr, "Expect result [%s]\n",
+                        escapeStrings[i].unescaped);
+                fprintf(stderr, "Actual result [(null)]\n");
+            }
+            return -1;
+        }
+        if (STRNEQ(escapeStrings[i].unescaped, unescaped)) {
+            virtTestDifference(stderr, escapeStrings[i].unescaped, unescaped);
+            VIR_FREE(unescaped);
+            return -1;
+        }
+        VIR_FREE(unescaped);
+    }
+
+    return 0;
+}
+
+static int
+mymain(void)
+{
+    int result = 0;
+
+# define DO_TEST(_name)                                                 \
+    do {                                                                \
+        if (virtTestRun("qemu monitor "#_name, 1, test##_name,          \
+                        NULL) < 0) {                                    \
+            result = -1;                                                \
+        }                                                               \
+    } while (0)
+
+    DO_TEST(EscapeArg);
+    DO_TEST(UnescapeArg);
+
+    return result == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+VIRT_TEST_MAIN(mymain)
+
+#else
+# include "testutils.h"
+
+int main(void)
+{
+    return EXIT_AM_SKIP;
+}
+
+#endif /* WITH_QEMU */