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OS-1840 fmdump shall emit JSON (newlines, fflush)
OS-1840 fmdump shall emit JSON (small fix 3)
OS-1840 fmdump shall emit JSON (small fix 2)
OS-1840 fmdump shall emit JSON (rm feedback)

@@ -11,357 +11,386 @@
 /*
  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <strings.h>
+#include <wchar.h>
+#include <sys/debug.h>
 
 #include "libnvpair.h"
 
+#define FPRINTF(fp, ...)                                \
+        do {                                            \
+                if (fprintf(fp, __VA_ARGS__) < 0)       \
+                        return (-1);                    \
+        } while (0)
+
 /*
  * When formatting a string for JSON output we must escape certain characters,
  * as described in RFC4627.  This applies to both member names and
  * DATA_TYPE_STRING values.
+ *
+ * This function will only operate correctly if the following conditions are
+ * met:
+ *
+ *       1. The input String is encoded in the current locale.
+ *
+ *       2. The current locale includes the Basic Multilingual Plane (plane 0)
+ *          as defined in the Unicode standard.
+ *
+ * The output will be entirely 7-bit ASCII (as a subset of UTF-8) with all
+ * representable Unicode characters included in their escaped numeric form.
  */
-static void
+static int
 nvlist_print_json_string(FILE *fp, const char *input)
 {
-        char c;
+        mbstate_t mbr;
+        wchar_t c;
+        size_t sz;
 
-        fprintf(fp, "\"");
-        while ((c = *input++) != '\0') {
+        bzero(&mbr, sizeof (mbr));
+
+        FPRINTF(fp, "\"");
+        while ((sz = mbrtowc(&c, input, MB_CUR_MAX, &mbr)) > 0) {
                 switch (c) {
                 case '"':
-                        fprintf(fp, "\\\"");
+                        FPRINTF(fp, "\\\"");
                         break;
                 case '\n':
-                        fprintf(fp, "\\n");
+                        FPRINTF(fp, "\\n");
                         break;
                 case '\r':
-                        fprintf(fp, "\\r");
+                        FPRINTF(fp, "\\r");
                         break;
                 case '\\':
-                        fprintf(fp, "\\\\");
+                        FPRINTF(fp, "\\\\");
                         break;
                 case '\f':
-                        fprintf(fp, "\\f");
+                        FPRINTF(fp, "\\f");
                         break;
                 case '\t':
-                        fprintf(fp, "\\t");
+                        FPRINTF(fp, "\\t");
                         break;
                 case '\b':
-                        fprintf(fp, "\\b");
+                        FPRINTF(fp, "\\b");
                         break;
                 default:
-                        if (c >= 0x00 && c <= 0x1f) {
-                                fprintf(fp, "\\u00%02hhu", c);
-                        } else {
-                                fprintf(fp, "%c", c);
+                        if ((c >= 0x00 && c <= 0x1f) ||
+                            (c > 0x7f && c <= 0xffff)) {
+                                /*
+                                 * Render both Control Characters and Unicode
+                                 * characters in the Basic Multilingual Plane
+                                 * as JSON-escaped multibyte characters.
+                                 */
+                                FPRINTF(fp, "\\u%04x", 0xffff & c);
+                        } else if (c >= 0x20 && c <= 0x7f) {
+                                /*
+                                 * Render other 7-bit ASCII characters directly
+                                 * and drop other, unrepresentable characters.
+                                 */
+                                FPRINTF(fp, "%c", 0xff & c);
                         }
                         break;
                 }
+                input += sz;
         }
-        fprintf(fp, "\"");
+
+        if (sz == (size_t)-1 || sz == (size_t)-2) {
+                /*
+                 * We last read an invalid multibyte character sequence,
+                 * so return an error.
+                 */
+                return (-1);
+        }
+
+        FPRINTF(fp, "\"");
+        return (0);
 }
 
-void
+/*
+ * Dump a JSON-formatted representation of an nvlist to the provided FILE *.
+ * This routine does not output any new-lines or additional whitespace other
+ * than that contained in strings, nor does it call fflush(3C).
+ */
+int
 nvlist_print_json(FILE *fp, nvlist_t *nvl)
 {
         nvpair_t *curr;
         boolean_t first = B_TRUE;
 
-        fprintf(fp, "{");
+        FPRINTF(fp, "{");
 
         for (curr = nvlist_next_nvpair(nvl, NULL); curr;
             curr = nvlist_next_nvpair(nvl, curr)) {
                 data_type_t type = nvpair_type(curr);
 
                 if (!first)
-                        fprintf(fp, ",");
+                        FPRINTF(fp, ",");
                 else
                         first = B_FALSE;
 
-                nvlist_print_json_string(fp, nvpair_name(curr));
-                fprintf(fp, ":");
+                if (nvlist_print_json_string(fp, nvpair_name(curr)) == -1)
+                        return (-1);
+                FPRINTF(fp, ":");
 
                 switch (type) {
                 case DATA_TYPE_STRING: {
-                        char *string;
-                        nvpair_value_string(curr, &string);
-                        nvlist_print_json_string(fp, string);
+                        char *string = fnvpair_value_string(curr);
+                        if (nvlist_print_json_string(fp, string) == -1)
+                                return (-1);
                         break;
                 }
 
                 case DATA_TYPE_BOOLEAN: {
-                        fprintf(fp, "true");
+                        FPRINTF(fp, "true");
                         break;
                 }
 
                 case DATA_TYPE_BOOLEAN_VALUE: {
-                        boolean_t boolean;
-                        nvpair_value_boolean_value(curr, &boolean);
-                        fprintf(fp, "%s", boolean == B_TRUE ? "true" :
-                            "false");
+                        FPRINTF(fp, "%s", fnvpair_value_boolean_value(curr) ==
+                            B_TRUE ? "true" : "false");
                         break;
                 }
 
                 case DATA_TYPE_BYTE: {
-                        uchar_t val;
-                        nvpair_value_byte(curr, &val);
-                        fprintf(fp, "%hhu", val);
+                        FPRINTF(fp, "%hhu", fnvpair_value_byte(curr));
                         break;
                 }
 
                 case DATA_TYPE_INT8: {
-                        int8_t val;
-                        nvpair_value_int8(curr, &val);
-                        fprintf(fp, "%hhd", val);
+                        FPRINTF(fp, "%hhd", fnvpair_value_int8(curr));
                         break;
                 }
 
                 case DATA_TYPE_UINT8: {
-                        uint8_t val;
-                        nvpair_value_uint8(curr, &val);
-                        fprintf(fp, "%hhu", val);
+                        FPRINTF(fp, "%hhu", fnvpair_value_uint8(curr));
                         break;
                 }
 
                 case DATA_TYPE_INT16: {
-                        int16_t val;
-                        nvpair_value_int16(curr, &val);
-                        fprintf(fp, "%hd", val);
+                        FPRINTF(fp, "%hd", fnvpair_value_int16(curr));
                         break;
                 }
 
                 case DATA_TYPE_UINT16: {
-                        uint16_t val;
-                        nvpair_value_uint16(curr, &val);
-                        fprintf(fp, "%hu", val);
+                        FPRINTF(fp, "%hu", fnvpair_value_uint16(curr));
                         break;
                 }
 
                 case DATA_TYPE_INT32: {
-                        int32_t val;
-                        nvpair_value_int32(curr, &val);
-                        fprintf(fp, "%d", val);
+                        FPRINTF(fp, "%d", fnvpair_value_int32(curr));
                         break;
                 }
 
                 case DATA_TYPE_UINT32: {
-                        uint32_t val;
-                        nvpair_value_uint32(curr, &val);
-                        fprintf(fp, "%u", val);
+                        FPRINTF(fp, "%u", fnvpair_value_uint32(curr));
                         break;
                 }
 
                 case DATA_TYPE_INT64: {
-                        int64_t val;
-                        nvpair_value_int64(curr, &val);
-                        fprintf(fp, "%lld", val);
+                        FPRINTF(fp, "%lld", fnvpair_value_int64(curr));
                         break;
                 }
 
                 case DATA_TYPE_UINT64: {
-                        uint64_t val;
-                        nvpair_value_uint64(curr, &val);
-                        fprintf(fp, "%llu", val);
+                        FPRINTF(fp, "%llu", fnvpair_value_uint64(curr));
                         break;
                 }
 
                 case DATA_TYPE_HRTIME: {
-                        hrtime_t val;
-                        nvpair_value_hrtime(curr, &val);
-                        fprintf(fp, "%llu", val);
+                        FPRINTF(fp, "%llu", fnvpair_value_hrtime(curr));
                         break;
                 }
 
                 case DATA_TYPE_DOUBLE: {
-                        double val;
-                        nvpair_value_double(curr, &val);
-                        fprintf(fp, "%f", val);
+                        FPRINTF(fp, "%f", fnvpair_value_double(curr));
                         break;
                 }
 
                 case DATA_TYPE_NVLIST: {
-                        nvlist_t *val;
-                        nvpair_value_nvlist(curr, &val);
-                        nvlist_print_json(fp, val);
+                        if (nvlist_print_json(fp,
+                            fnvpair_value_nvlist(curr)) == -1)
+                                return (-1);
                         break;
                 }
 
                 case DATA_TYPE_STRING_ARRAY: {
                         char **val;
-                        uint_t valsz, pos;
-                        nvpair_value_string_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                nvlist_print_json_string(fp, val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_string_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                if (nvlist_print_json_string(fp, val[i]) == -1)
+                                        return (-1);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_NVLIST_ARRAY: {
                         nvlist_t **val;
-                        uint_t valsz, pos;
-                        nvpair_value_nvlist_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                nvlist_print_json(fp, val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_nvlist_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                if (nvlist_print_json(fp, val[i]) == -1)
+                                        return (-1);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_BOOLEAN_ARRAY: {
                         boolean_t *val;
-                        uint_t valsz, pos;
-                        nvpair_value_boolean_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                fprintf(fp, val[pos] == B_TRUE ?
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_boolean_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                FPRINTF(fp, val[i] == B_TRUE ?
                                     "true" : "false");
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_BYTE_ARRAY: {
                         uchar_t *val;
-                        uint_t valsz, pos;
-                        nvpair_value_byte_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                fprintf(fp, "%hhu", val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_byte_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                FPRINTF(fp, "%hhu", val[i]);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_UINT8_ARRAY: {
                         uint8_t *val;
-                        uint_t valsz, pos;
-                        nvpair_value_uint8_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                fprintf(fp, "%hhu", val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_uint8_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                FPRINTF(fp, "%hhu", val[i]);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_INT8_ARRAY: {
                         int8_t *val;
-                        uint_t valsz, pos;
-                        nvpair_value_int8_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                fprintf(fp, "%hd", val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_int8_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                FPRINTF(fp, "%hd", val[i]);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_UINT16_ARRAY: {
                         uint16_t *val;
-                        uint_t valsz, pos;
-                        nvpair_value_uint16_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                fprintf(fp, "%hu", val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_uint16_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                FPRINTF(fp, "%hu", val[i]);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_INT16_ARRAY: {
                         int16_t *val;
-                        uint_t valsz, pos;
-                        nvpair_value_int16_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                fprintf(fp, "%hhd", val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_int16_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                FPRINTF(fp, "%hhd", val[i]);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_UINT32_ARRAY: {
                         uint32_t *val;
-                        uint_t valsz, pos;
-                        nvpair_value_uint32_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                fprintf(fp, "%u", val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_uint32_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                FPRINTF(fp, "%u", val[i]);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_INT32_ARRAY: {
                         int32_t *val;
-                        uint_t valsz, pos;
-                        nvpair_value_int32_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                fprintf(fp, "%d", val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_int32_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                FPRINTF(fp, "%d", val[i]);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_UINT64_ARRAY: {
                         uint64_t *val;
-                        uint_t valsz, pos;
-                        nvpair_value_uint64_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                fprintf(fp, "%llu", val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_uint64_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                FPRINTF(fp, "%llu", val[i]);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_INT64_ARRAY: {
                         int64_t *val;
-                        uint_t valsz, pos;
-                        nvpair_value_int64_array(curr, &val, &valsz);
-                        fprintf(fp, "[");
-                        for (pos = 0; pos < valsz; pos++) {
-                                if (pos > 0)
-                                        fprintf(fp, ",");
-                                fprintf(fp, "%lld", val[pos]);
+                        uint_t valsz, i;
+                        VERIFY0(nvpair_value_int64_array(curr, &val, &valsz));
+                        FPRINTF(fp, "[");
+                        for (i = 0; i < valsz; i++) {
+                                if (i > 0)
+                                        FPRINTF(fp, ",");
+                                FPRINTF(fp, "%lld", val[i]);
                         }
-                        fprintf(fp, "]");
+                        FPRINTF(fp, "]");
                         break;
                 }
 
                 case DATA_TYPE_UNKNOWN:
-                        fprintf(fp, "null");
-                        break;
+                        return (-1);
                 }
         }
 
-        fprintf(fp, "}");
+        FPRINTF(fp, "}");
+        return (0);
 }