Add new output-only formats and Define constants for the different plist formats

This commit introduces constants for the different plist formats,
and adds 3 new human-readable output-only formats:
- PLIST_FORMAT_PRINT: the default human-readable format
- PLIST_FORMAT_LIMD: "libimobiledevice" format (used in ideviceinfo)
- PLIST_FORMAT_PLUTIL: plutil-style format

Also, a new set of write functions has been added:
- plist_write_to_string
- plist_write_to_stream
- plist_write_to_file

Plus a simple "dump" function:
- plist_print

See documentation for details.

1 files changed, 449 insertions, 0 deletions

diff --git a/src/out-limd.c b/src/out-limd.c
new file mode 100644
index 0000000..0ff9a65
--- /dev/null
+++ b/src/out-limd.c
@@ -0,0 +1,449 @@
+/*
+ * out-limd.c
+ * libplist *output-only* format introduced by libimobiledevice/ideviceinfo
+ *  - NOT for machine parsing
+ *
+ * Copyright (c) 2022-2023 Nikias Bassen All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+
+#include <inttypes.h>
+#include <ctype.h>
+#include <math.h>
+#include <limits.h>
+
+#include <node.h>
+
+#include "plist.h"
+#include "strbuf.h"
+#include "time64.h"
+#include "base64.h"
+
+#define MAC_EPOCH 978307200
+
+static size_t dtostr(char *buf, size_t bufsize, double realval)
+{
+    size_t len = 0;
+    if (isnan(realval)) {
+        len = snprintf(buf, bufsize, "nan");
+    } else if (isinf(realval)) {
+        len = snprintf(buf, bufsize, "%cinfinity", (realval > 0.0) ? '+' : '-');
+    } else if (realval == 0.0f) {
+        len = snprintf(buf, bufsize, "0.0");
+    } else {
+        size_t i = 0;
+        len = snprintf(buf, bufsize, "%.*g", 17, realval);
+        for (i = 0; buf && i < len; i++) {
+            if (buf[i] == ',') {
+                buf[i] = '.';
+                break;
+            } else if (buf[i] == '.') {
+                break;
+            }
+        }
+    }
+    return len;
+}
+
+static int node_to_string(node_t node, bytearray_t **outbuf, uint32_t depth, uint32_t indent)
+{
+    plist_data_t node_data = NULL;
+
+    char *val = NULL;
+    size_t val_len = 0;
+    char buf[16];
+
+    uint32_t i = 0;
+
+    if (!node)
+        return PLIST_ERR_INVALID_ARG;
+
+    node_data = plist_get_data(node);
+
+    switch (node_data->type)
+    {
+    case PLIST_BOOLEAN:
+    {
+        if (node_data->boolval) {
+            str_buf_append(*outbuf, "true", 4);
+        } else {
+            str_buf_append(*outbuf, "false", 5);
+        }
+    }
+    break;
+
+    case PLIST_NULL:
+        str_buf_append(*outbuf, "null", 4);
+        break;
+
+    case PLIST_INT:
+        val = (char*)malloc(64);
+        if (node_data->length == 16) {
+            val_len = snprintf(val, 64, "%"PRIu64, node_data->intval);
+        } else {
+            val_len = snprintf(val, 64, "%"PRIi64, node_data->intval);
+        }
+        str_buf_append(*outbuf, val, val_len);
+        free(val);
+        break;
+
+    case PLIST_REAL:
+        val = (char*)malloc(64);
+        val_len = dtostr(val, 64, node_data->realval);
+        str_buf_append(*outbuf, val, val_len);
+        free(val);
+        break;
+
+    case PLIST_STRING:
+    case PLIST_KEY: {
+        const char *charmap[32] = {
+            "\\u0000", "\\u0001", "\\u0002", "\\u0003", "\\u0004", "\\u0005", "\\u0006", "\\u0007",
+            "\\b",     "\\t",     "\\n",     "\\u000b", "\\f",     "\\r",     "\\u000e", "\\u000f",
+            "\\u0010", "\\u0011", "\\u0012", "\\u0013", "\\u0014", "\\u0015", "\\u0016", "\\u0017",
+            "\\u0018", "\\u0019", "\\u001a", "\\u001b", "\\u001c", "\\u001d", "\\u001e", "\\u001f",
+        };
+        size_t j = 0;
+        size_t len = 0;
+        off_t start = 0;
+        off_t cur = 0;
+
+        len = node_data->length;
+        for (j = 0; j < len; j++) {
+            unsigned char ch = (unsigned char)node_data->strval[j];
+            if (ch < 0x20) {
+                str_buf_append(*outbuf, node_data->strval + start, cur - start);
+                str_buf_append(*outbuf, charmap[ch], (charmap[ch][1] == 'u') ? 6 : 2);
+                start = cur+1;
+            }
+            cur++;
+        }
+        str_buf_append(*outbuf, node_data->strval + start, cur - start);
+        } break;
+
+    case PLIST_ARRAY: {
+        node_t ch;
+        uint32_t cnt = 0;
+        for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
+            if (cnt > 0 || (cnt == 0 && node->parent != NULL)) {
+                str_buf_append(*outbuf, "\n", 1);
+                for (i = 0; i < depth+indent; i++) {
+                    str_buf_append(*outbuf, " ", 1);
+                }
+            }
+            size_t sl = sprintf(buf, "%u: ", cnt);
+            str_buf_append(*outbuf, buf, sl);
+            int res = node_to_string(ch, outbuf, depth+1, indent);
+            if (res < 0) {
+                return res;
+            }
+            cnt++;
+        }
+        } break;
+    case PLIST_DICT: {
+        node_t ch;
+        uint32_t cnt = 0;
+        for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
+            if (cnt > 0 && cnt % 2 == 0) {
+                str_buf_append(*outbuf, "\n", 1);
+                for (i = 0; i < depth+indent; i++) {
+                    str_buf_append(*outbuf, " ", 1);
+                }
+            }
+            int res = node_to_string(ch, outbuf, depth+1, indent);
+            if (res < 0) {
+                return res;
+            }
+            if (cnt % 2 == 0) {
+                plist_t valnode = (plist_t)node_next_sibling(ch);
+                if (PLIST_IS_ARRAY(valnode)) {
+                    size_t sl = sprintf(buf, "[%u]:", plist_array_get_size(valnode));
+                    str_buf_append(*outbuf, buf, sl);
+                } else {
+                    str_buf_append(*outbuf, ": ", 2);
+                }
+            }
+            cnt++;
+        }
+        } break;
+    case PLIST_DATA:
+        {
+            val = (char*)malloc(4096);
+            size_t done = 0;
+            while (done < node_data->length) {
+                size_t amount = node_data->length - done;
+                if (amount > 3072) {
+                    amount = 3072;
+                }
+                size_t bsize = base64encode(val, node_data->buff + done, amount);
+                str_buf_append(*outbuf, val, bsize);
+                done += amount;
+            }
+        }
+        break;
+    case PLIST_DATE:
+        {
+            Time64_T timev = (Time64_T)node_data->realval + MAC_EPOCH;
+            struct TM _btime;
+            struct TM *btime = gmtime64_r(&timev, &_btime);
+            if (btime) {
+                val = (char*)calloc(1, 24);
+                struct tm _tmcopy;
+                copy_TM64_to_tm(btime, &_tmcopy);
+                val_len = strftime(val, 24, "%Y-%m-%dT%H:%M:%SZ", &_tmcopy);
+                if (val_len > 0) {
+                    str_buf_append(*outbuf, val, val_len);
+                }
+                free(val);
+                val = NULL;
+            }
+        }
+        break;
+    case PLIST_UID:
+        {
+            str_buf_append(*outbuf, "CF$UID:", 7);
+            val = (char*)malloc(64);
+            if (node_data->length == 16) {
+                val_len = snprintf(val, 64, "%"PRIu64, node_data->intval);
+            } else {
+                val_len = snprintf(val, 64, "%"PRIi64, node_data->intval);
+            }
+            str_buf_append(*outbuf, val, val_len);
+            free(val);
+        }
+        break;
+    default:
+        return PLIST_ERR_UNKNOWN;
+    }
+
+    return PLIST_ERR_SUCCESS;
+}
+
+#define PO10i_LIMIT (INT64_MAX/10)
+
+/* based on https://stackoverflow.com/a/4143288 */
+static int num_digits_i(int64_t i)
+{
+    int n;
+    int64_t po10;
+    n=1;
+    if (i < 0) {
+        i = (i == INT64_MIN) ? INT64_MAX : -i;
+        n++;
+    }
+    po10=10;
+    while (i>=po10) {
+        n++;
+        if (po10 > PO10i_LIMIT) break;
+        po10*=10;
+    }
+    return n;
+}
+
+#define PO10u_LIMIT (UINT64_MAX/10)
+
+/* based on https://stackoverflow.com/a/4143288 */
+static int num_digits_u(uint64_t i)
+{
+    int n;
+    uint64_t po10;
+    n=1;
+    po10=10;
+    while (i>=po10) {
+        n++;
+        if (po10 > PO10u_LIMIT) break;
+        po10*=10;
+    }
+    return n;
+}
+
+static int node_estimate_size(node_t node, uint64_t *size, uint32_t depth, uint32_t indent)
+{
+    plist_data_t data;
+    if (!node) {
+        return PLIST_ERR_INVALID_ARG;
+    }
+    data = plist_get_data(node);
+    if (node->children) {
+        node_t ch;
+        unsigned int n_children = node_n_children(node);
+        for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
+            int res = node_estimate_size(ch, size, depth + 1, indent);
+            if (res < 0) {
+                return res;
+            }
+        }
+        switch (data->type) {
+        case PLIST_DICT:
+            *size += n_children-1; // number of ':' and ' '
+            *size += n_children; // number of '\n' and extra space
+            *size += (uint64_t)n_children * (depth+indent+1); // indent for every 2nd child
+            *size += indent+1; // additional '\n'
+            break;
+        case PLIST_ARRAY:
+            *size += n_children-1; // number of ','
+            *size += n_children; // number of '\n'
+            *size += (uint64_t)n_children * ((depth+indent+1)<<1); // indent for every child
+            *size += indent+1; // additional '\n'
+            break;
+        default:
+            break;
+        }
+    } else {
+        switch (data->type) {
+        case PLIST_STRING:
+        case PLIST_KEY:
+            *size += data->length;
+            break;
+        case PLIST_INT:
+            if (data->length == 16) {
+                *size += num_digits_u(data->intval);
+            } else {
+                *size += num_digits_i((int64_t)data->intval);
+            }
+            break;
+        case PLIST_REAL:
+            *size += dtostr(NULL, 0, data->realval);
+            break;
+        case PLIST_BOOLEAN:
+            *size += ((data->boolval) ? 4 : 5);
+            break;
+        case PLIST_NULL:
+            *size += 4;
+            break;
+        case PLIST_DICT:
+        case PLIST_ARRAY:
+            *size += 3;
+            break;
+        case PLIST_DATA:
+            *size += (data->length / 3) * 4 + 4;
+            break;
+        case PLIST_DATE:
+            *size += 23;
+            break;
+        case PLIST_UID:
+            *size += 7; // "CF$UID:"
+            *size += num_digits_u(data->intval);
+            break;
+        default:
+#ifdef DEBUG
+            fprintf(stderr, "%s: invalid node type encountered\n", __func__);
+#endif
+            return PLIST_ERR_UNKNOWN;
+        }
+    }
+    if (depth == 0) {
+        *size += 1; // final newline
+    }
+    return PLIST_ERR_SUCCESS;
+}
+
+static plist_err_t _plist_write_to_strbuf(plist_t plist, strbuf_t *outbuf, plist_write_options_t options)
+{
+    uint8_t indent = 0;
+    if (options & PLIST_OPT_INDENT) {
+        indent = (options >> 24) & 0xFF;
+    }
+    uint8_t i;
+    for (i = 0; i < indent; i++) {
+        str_buf_append(outbuf, " ", 1);
+    }
+    int res = node_to_string(plist, &outbuf, 0, indent);
+    if (res < 0) {
+        return res;
+    }
+    if (!(options & PLIST_OPT_NO_NEWLINE)) {
+        str_buf_append(outbuf, "\n", 1);
+    }
+    return res;
+}
+
+plist_err_t plist_write_to_string_limd(plist_t plist, char **output, uint32_t* length, plist_write_options_t options)
+{
+    uint64_t size = 0;
+    int res;
+
+    if (!plist || !output || !length) {
+        return PLIST_ERR_INVALID_ARG;
+    }
+
+    uint8_t indent = 0;
+    if (options & PLIST_OPT_INDENT) {
+        indent = (options >> 24) & 0xFF;
+    }
+
+    res = node_estimate_size(plist, &size, 0, indent);
+    if (res < 0) {
+        return res;
+    }
+
+    strbuf_t *outbuf = str_buf_new(size);
+    if (!outbuf) {
+#if DEBUG
+        fprintf(stderr, "%s: Could not allocate output buffer\n", __func__);
+#endif
+        return PLIST_ERR_NO_MEM;
+    }
+
+    res = _plist_write_to_strbuf(plist, outbuf, options);
+    if (res < 0) {
+        str_buf_free(outbuf);
+        *output = NULL;
+        *length = 0;
+        return res;
+    }
+    str_buf_append(outbuf, "\0", 1);
+
+    *output = outbuf->data;
+    *length = outbuf->len - 1;
+
+    outbuf->data = NULL;
+    str_buf_free(outbuf);
+
+    return PLIST_ERR_SUCCESS;
+}
+
+plist_err_t plist_write_to_stream_limd(plist_t plist, FILE *stream, plist_write_options_t options)
+{
+    if (!plist || !stream) {
+        return PLIST_ERR_INVALID_ARG;
+    }
+    strbuf_t *outbuf = str_buf_new_for_stream(stream);
+    if (!outbuf) {
+#if DEBUG
+        fprintf(stderr, "%s: Could not allocate output buffer\n", __func__);
+#endif
+        return PLIST_ERR_NO_MEM;
+    }
+
+    int res = _plist_write_to_strbuf(plist, outbuf, options);
+    if (res < 0) {
+        str_buf_free(outbuf);
+        return res;
+    }
+
+    str_buf_free(outbuf);
+
+    return PLIST_ERR_SUCCESS;
+}