Initial version.

src/nxt_errno.c

@@ -0,0 +1,152 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) NGINX, Inc.
+ */
+
+#include <nxt_main.h>
+
+
+/*
+ * The strerror() messages are copied because:
+ *
+ * 1) strerror() and strerror_r() functions are not Async-Signal-Safe,
+ *    therefore, they can not be used in signal handlers;
+ *
+ * 2) a direct sys_errlist[] array may be used instead of these functions,
+ *    but Linux linker warns about this usage:
+ *
+ * warning: `sys_errlist' is deprecated; use `strerror' or `strerror_r' instead
+ * warning: `sys_nerr' is deprecated; use `strerror' or `strerror_r' instead
+ *
+ *    causing false bug reports.
+ */
+
+static u_char *nxt_bootstrap_strerror(nxt_err_t err, u_char *errstr,
+    size_t size);
+static u_char *nxt_runtime_strerror(nxt_err_t err, u_char *errstr, size_t size);
+
+
+nxt_strerror_t     nxt_strerror = nxt_bootstrap_strerror;
+static nxt_str_t   *nxt_sys_errlist;
+static nxt_uint_t  nxt_sys_nerr;
+
+
+nxt_int_t
+nxt_strerror_start(void)
+{
+    char        *msg;
+    u_char      *p;
+    size_t      size, len, n;
+    nxt_uint_t  err, invalid;
+
+    /* The last entry. */
+    size = sizeof("Unknown error") - 1;
+
+    /*
+     * Linux has holes for error codes 41 and 58, so the loop
+     * stops only after 100 invalid codes in succession.
+     */
+
+    for (invalid = 0; invalid < 100 && nxt_sys_nerr < 65536; nxt_sys_nerr++) {
+
+        nxt_set_errno(0);
+        msg = strerror((int) nxt_sys_nerr);
+
+        /*
+         * strerror() behaviour on passing invalid error code depends
+         * on OS and version:
+         *   Linux returns "Unknown error NN";
+         *   FreeBSD, NetBSD and OpenBSD return "Unknown error: NN"
+         *     and set errno to EINVAL;
+         *   Solaris 10 returns "Unknown error" and sets errno to EINVAL;
+         *   Solaris 9 returns "Unknown error";
+         *   Solaris 2 returns NULL;
+         *   MacOSX returns "Unknown error: NN";
+         *   AIX returns "Error NNN occurred.";
+         *   HP-UX returns "Unknown error" for invalid codes lesser than 250
+         *     or empty string for larger codes.
+         */
+
+        if (msg == NULL) {
+            invalid++;
+            continue;
+        }
+
+        len = nxt_strlen(msg);
+        size += len;
+
+        if (len == 0  /* HP-UX empty strings. */
+            || nxt_errno == NXT_EINVAL
+            || nxt_memcmp(msg, "Unknown error", 13) == 0)
+        {
+            invalid++;
+            continue;
+        }
+
+#if (NXT_AIX)
+
+        if (nxt_memcmp(msg, "Error ", 6) == 0
+            && nxt_memcmp(msg + len - 10, " occurred.", 9) == 0)
+        {
+            invalid++;
+            continue;
+        }
+
+#endif
+    }
+
+    nxt_sys_nerr -= invalid;
+
+    nxt_main_log_debug("sys_nerr: %d", nxt_sys_nerr);
+
+    n = (nxt_sys_nerr + 1) * sizeof(nxt_str_t);
+
+    nxt_sys_errlist = nxt_malloc(n + size);
+    if (nxt_sys_errlist == NULL) {
+        return NXT_ERROR;
+    }
+
+    p = (u_char *) nxt_sys_errlist + n;
+
+    for (err = 0; err < nxt_sys_nerr; err++) {
+        msg = strerror((int) err);
+        len = nxt_strlen(msg);
+
+        nxt_sys_errlist[err].len = len;
+        nxt_sys_errlist[err].data = p;
+
+        p = nxt_cpymem(p, msg, len);
+    }
+
+    nxt_sys_errlist[err].len = 13;
+    nxt_sys_errlist[err].data = p;
+    nxt_memcpy(p, "Unknown error", 13);
+
+    nxt_strerror = nxt_runtime_strerror;
+
+    return NXT_OK;
+}
+
+
+static u_char *
+nxt_bootstrap_strerror(nxt_err_t err, u_char *errstr, size_t size)
+{
+    return nxt_cpystrn(errstr, (u_char *) strerror(err), size);
+}
+
+
+static u_char *
+nxt_runtime_strerror(nxt_err_t err, u_char *errstr, size_t size)
+{
+    nxt_str_t   *msg;
+    nxt_uint_t  n;
+
+    n = nxt_min((nxt_uint_t) err, nxt_sys_nerr);
+
+    msg = &nxt_sys_errlist[n];
+
+    size = nxt_min(size, msg->len);
+
+    return nxt_cpymem(errstr, msg->data, size);
+}