[v2,05/21] hw/uefi: add var-service-utils.c

Commit Message

Gerd Hoffmann Jan. 7, 2025, 3:33 p.m. UTC

Add utility functions.  Helpers for UEFI (ucs2) string handling.
Helpers for readable trace messages.  Compare UEFI time stamps.

Signed-off-by: Gerd Hoffmann <[e-mail]>
---
 hw/uefi/var-service-utils.c | 241 ++++++++++++++++++++++++++++++++++++
 1 file changed, 241 insertions(+)
 create mode 100644 hw/uefi/var-service-utils.c

Patch

diff --git a/hw/uefi/var-service-utils.c b/hw/uefi/var-service-utils.c
new file mode 100644
index 000000000000..c9ef46570f48
--- /dev/null
+++ b/hw/uefi/var-service-utils.c
@@ -0,0 +1,241 @@ 
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * uefi vars device - helper functions for ucs2 strings and tracing
+ */
+#include "qemu/osdep.h"
+#include "system/dma.h"
+
+#include "hw/uefi/var-service.h"
+
+#include "trace/trace-hw_uefi.h"
+
+/* ------------------------------------------------------------------ */
+
+/*
+ * string helper functions.
+ *
+ * Most of the time uefi ucs2 strings are NULL-terminated, except
+ * sometimes when they are not (for example in variable policies).
+ */
+
+gboolean uefi_str_is_valid(const uint16_t *str, size_t len,
+                           gboolean must_be_null_terminated)
+{
+    size_t pos = 0;
+
+    for (;;) {
+        if (pos == len) {
+            if (must_be_null_terminated) {
+                return false;
+            } else {
+                return true;
+            }
+        }
+        switch (str[pos]) {
+        case 0:
+            /* end of string */
+            return true;
+        case 0xd800 ... 0xdfff:
+            /* reject surrogates */
+            return false;
+        default:
+            /* char is good, check next */
+            break;
+        }
+        pos++;
+    }
+}
+
+size_t uefi_strlen(const uint16_t *str, size_t len)
+{
+    size_t pos = 0;
+
+    for (;;) {
+        if (pos == len) {
+            return pos;
+        }
+        if (str[pos] == 0) {
+            return pos;
+        }
+        pos++;
+    }
+}
+
+gboolean uefi_str_equal_ex(const uint16_t *a, size_t alen,
+                           const uint16_t *b, size_t blen,
+                           gboolean wildcards_in_a)
+{
+    size_t pos = 0;
+
+    alen = alen / 2;
+    blen = blen / 2;
+    for (;;) {
+        if (pos == alen && pos == blen) {
+            return true;
+        }
+        if (pos == alen && b[pos] == 0) {
+            return true;
+        }
+        if (pos == blen && a[pos] == 0) {
+            return true;
+        }
+        if (pos == alen || pos == blen) {
+            return false;
+        }
+        if (a[pos] == 0 && b[pos] == 0) {
+            return true;
+        }
+
+        if (wildcards_in_a && a[pos] == '#') {
+            if (!isxdigit(b[pos])) {
+                return false;
+            }
+        } else {
+            if (a[pos] != b[pos]) {
+                return false;
+            }
+        }
+        pos++;
+    }
+}
+
+gboolean uefi_str_equal(const uint16_t *a, size_t alen,
+                        const uint16_t *b, size_t blen)
+{
+    return uefi_str_equal_ex(a, alen, b, blen, false);
+}
+
+char *uefi_ucs2_to_ascii(const uint16_t *ucs2, uint64_t ucs2_size)
+{
+    char *str = g_malloc0(ucs2_size / 2 + 1);
+    int i;
+
+    for (i = 0; i * 2 < ucs2_size; i++) {
+        if (ucs2[i] == 0) {
+            break;
+        }
+        if (ucs2[i] < 128) {
+            str[i] = ucs2[i];
+        } else {
+            str[i] = '?';
+        }
+    }
+    str[i] = 0;
+    return str;
+}
+
+/* ------------------------------------------------------------------ */
+/* time helper functions                                              */
+
+int uefi_time_compare(efi_time *a, efi_time *b)
+{
+    if (a->year < b->year) {
+        return -1;
+    }
+    if (a->year > b->year) {
+        return 1;
+    }
+
+    if (a->month < b->month) {
+        return -1;
+    }
+    if (a->month > b->month) {
+        return 1;
+    }
+
+    if (a->day < b->day) {
+        return -1;
+    }
+    if (a->day > b->day) {
+        return 1;
+    }
+
+    if (a->hour < b->hour) {
+        return -1;
+    }
+    if (a->hour > b->hour) {
+        return 1;
+    }
+
+    if (a->minute < b->minute) {
+        return -1;
+    }
+    if (a->minute > b->minute) {
+        return 1;
+    }
+
+    if (a->second < b->second) {
+        return -1;
+    }
+    if (a->second > b->second) {
+        return 1;
+    }
+
+    if (a->nanosecond < b->nanosecond) {
+        return -1;
+    }
+    if (a->nanosecond > b->nanosecond) {
+        return 1;
+    }
+
+    return 0;
+}
+
+/* ------------------------------------------------------------------ */
+/* tracing helper functions                                           */
+
+void uefi_trace_variable(const char *action, QemuUUID guid,
+                         const uint16_t *name, uint64_t name_size)
+{
+    QemuUUID be = qemu_uuid_bswap(guid);
+    char *str_uuid = qemu_uuid_unparse_strdup(&be);
+    char *str_name = uefi_ucs2_to_ascii(name, name_size);
+
+    trace_uefi_variable(action, str_name, name_size, str_uuid);
+
+    g_free(str_name);
+    g_free(str_uuid);
+}
+
+void uefi_trace_status(const char *action, efi_status status)
+{
+    switch (status) {
+    case EFI_SUCCESS:
+        trace_uefi_status(action, "success");
+        break;
+    case EFI_INVALID_PARAMETER:
+        trace_uefi_status(action, "invalid parameter");
+        break;
+    case EFI_UNSUPPORTED:
+        trace_uefi_status(action, "unsupported");
+        break;
+    case EFI_BAD_BUFFER_SIZE:
+        trace_uefi_status(action, "bad buffer size");
+        break;
+    case EFI_BUFFER_TOO_SMALL:
+        trace_uefi_status(action, "buffer too small");
+        break;
+    case EFI_WRITE_PROTECTED:
+        trace_uefi_status(action, "write protected");
+        break;
+    case EFI_OUT_OF_RESOURCES:
+        trace_uefi_status(action, "out of resources");
+        break;
+    case EFI_NOT_FOUND:
+        trace_uefi_status(action, "not found");
+        break;
+    case EFI_ACCESS_DENIED:
+        trace_uefi_status(action, "access denied");
+        break;
+    case EFI_ALREADY_STARTED:
+        trace_uefi_status(action, "already started");
+        break;
+    case EFI_SECURITY_VIOLATION:
+        trace_uefi_status(action, "security violation");
+        break;
+    default:
+        trace_uefi_status(action, "unknown error");
+        break;
+    }
+}