1 files changed, 51 insertions, 22 deletions

diff --git a/src/log.c b/src/log.c
index 982bdb7..d6f0934 100644
--- a/src/log.c
+++ b/src/log.c
@@ -7,57 +7,86 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+
 #include "fido.h"
 
 #ifndef FIDO_NO_DIAGNOSTIC
 
+#define XXDLEN  32
+#define XXDROW  128
+#define LINELEN 256
+
 #ifndef TLS
 #define TLS
 #endif
 
 static TLS int logging;
+static TLS fido_log_handler_t *log_handler;
+
+static void
+log_on_stderr(const char *str)
+{
+        fprintf(stderr, "%s", str);
+}
 
 void
 fido_log_init(void)
 {
         logging = 1;
+        log_handler = log_on_stderr;
 }
 
 void
-fido_log_xxd(const void *buf, size_t count)
+fido_log_debug(const char *fmt, ...)
 {
-        const uint8_t   *ptr = buf;
-        size_t           i;
+        char line[LINELEN];
+        va_list ap;
+        int r;
 
-        if (!logging)
+        if (!logging || log_handler == NULL)
                 return;
 
-        fprintf(stderr, "  ");
-
-        for (i = 0; i < count; i++) {
-                fprintf(stderr, "%02x ", *ptr++);
-                if ((i + 1) % 16 == 0 && i + 1 < count)
-                        fprintf(stderr, "\n  ");
-        }
-
-        fprintf(stderr, "\n");
-        fflush(stderr);
+        va_start(ap, fmt);
+        r = vsnprintf(line, sizeof(line) - 1, fmt, ap);
+        va_end(ap);
+        if (r < 0 || (size_t)r >= sizeof(line) - 1)
+                return;
+        strlcat(line, "\n", sizeof(line));
+        log_handler(line);
 }
 
 void
-fido_log_debug(const char *fmt, ...)
+fido_log_xxd(const void *buf, size_t count)
 {
-        va_list  ap;
+        const uint8_t *ptr = buf;
+        char row[XXDROW];
+        char xxd[XXDLEN];
 
-        if (!logging)
+        if (!logging || log_handler == NULL || count == 0)
                 return;
 
-        va_start(ap, fmt);
-        vfprintf(stderr, fmt, ap);
-        va_end(ap);
+        *row = '\0';
 
-        fprintf(stderr, "\n");
-        fflush(stderr);
+        for (size_t i = 0; i < count; i++) {
+                *xxd = '\0';
+                if (i % 16 == 0)
+                        snprintf(xxd, sizeof(xxd), "%04zu: %02x", i, *ptr++);
+                else
+                        snprintf(xxd, sizeof(xxd), " %02x", *ptr++);
+                strlcat(row, xxd, sizeof(row));
+                if (i % 16 == 15 || i == count - 1) {
+                        fido_log_debug("%s", row);
+                        *row = '\0';
+                }
+        }
+}
+
+void
+fido_set_log_handler(fido_log_handler_t *handler)
+{
+        if (handler != NULL)
+                log_handler = handler;
 }
 
 #endif /* !FIDO_NO_DIAGNOSTIC */