+/*
+ * libuci - Library for the Unified Configuration Interface
+ * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
+ *
+ * this program is free software; you can redistribute it and/or modify
+ * it under the terms of the gnu lesser general public license version 2.1
+ * as published by the free software foundation
+ *
+ * This program 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 General Public License for more details.
+ */
+
+/*
+ * This file contains the code for parsing uci config files
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#define LINEBUF 128
+#define LINEBUF_MAX 4096
+
+/*
+ * Fetch a new line from the input stream and resize buffer if necessary
+ */
+static void uci_getln(struct uci_context *ctx)
+{
+ struct uci_parse_context *pctx = ctx->pctx;
+ char *p;
+ int ofs;
+
+ if (pctx->buf == NULL) {
+ pctx->buf = uci_malloc(ctx, LINEBUF);
+ pctx->bufsz = LINEBUF;
+ }
+
+ ofs = 0;
+ do {
+ p = &pctx->buf[ofs];
+ p[ofs] = 0;
+
+ p = fgets(p, pctx->bufsz - ofs, pctx->file);
+ if (!p || !p[ofs])
+ return;
+
+ ofs += strlen(p);
+ if (pctx->buf[ofs - 1] == '\n') {
+ pctx->line++;
+ pctx->buf[ofs - 1] = 0;
+ return;
+ }
+
+ if (pctx->bufsz > LINEBUF_MAX/2) {
+ pctx->reason = "line too long";
+ pctx->byte = LINEBUF_MAX;
+ UCI_THROW(ctx, UCI_ERR_PARSE);
+ }
+
+ pctx->bufsz *= 2;
+ pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
+ } while (1);
+}
+
+/*
+ * Clean up all extra memory used by the parser
+ */
+static void uci_parse_cleanup(struct uci_context *ctx)
+{
+ struct uci_parse_context *pctx;
+
+ pctx = ctx->pctx;
+ if (!pctx)
+ return;
+
+ ctx->pctx = NULL;
+ if (pctx->cfg) {
+ uci_list_del(&pctx->cfg->list);
+ uci_drop_config(pctx->cfg);
+ }
+ if (pctx->buf)
+ free(pctx->buf);
+ if (pctx->file)
+ fclose(pctx->file);
+
+ free(pctx);
+}
+
+/*
+ * move the string pointer forward until a non-whitespace character or
+ * EOL is reached
+ */
+static void skip_whitespace(char **str)
+{
+ while (**str && isspace(**str))
+ *str += 1;
+}
+
+static inline void addc(char **dest, char **src)
+{
+ **dest = **src;
+ *dest += 1;
+ *src += 1;
+}
+
+static inline void parse_backslash(char **str, char **target)
+{
+ /* skip backslash */
+ *str += 1;
+ /* FIXME: decode escaped characters? */
+ addc(target, str);
+}
+
+/*
+ * parse a double quoted string argument from the command line
+ */
+static void parse_double_quote(struct uci_context *ctx, char **str, char **target)
+{
+ char c;
+
+ /* skip quote character */
+ *str += 1;
+
+ while ((c = **str)) {
+ switch(c) {
+ case '\\':
+ parse_backslash(str, target);
+ continue;
+ case '"':
+ **target = 0;
+ *str += 1;
+ return;
+ default:
+ addc(target, str);
+ break;
+ }
+ }
+ ctx->pctx->reason = "unterminated \"";
+ ctx->pctx->byte = *str - ctx->pctx->buf;
+ UCI_THROW(ctx, UCI_ERR_PARSE);
+}
+
+/*
+ * parse a single quoted string argument from the command line
+ */
+static void parse_single_quote(struct uci_context *ctx, char **str, char **target)
+{
+ char c;
+ /* skip quote character */
+ *str += 1;
+
+ while ((c = **str)) {
+ switch(c) {
+ case '\'':
+ **target = 0;
+ *str += 1;
+ return;
+ default:
+ addc(target, str);
+ }
+ }
+ ctx->pctx->reason = "unterminated '";
+ ctx->pctx->byte = *str - ctx->pctx->buf;
+ UCI_THROW(ctx, UCI_ERR_PARSE);
+}
+
+/*
+ * parse a string from the command line and detect the quoting style
+ */
+static void parse_str(struct uci_context *ctx, char **str, char **target)
+{
+ do {
+ switch(**str) {
+ case '\\':
+ parse_backslash(str, target);
+ continue;
+ case '\'':
+ parse_single_quote(ctx, str, target);
+ break;
+ case '"':
+ parse_double_quote(ctx, str, target);
+ break;
+ case 0:
+ goto done;
+ default:
+ addc(target, str);
+ break;
+ }
+ } while (**str && !isspace(**str));
+done:
+
+ /*
+ * if the string was unquoted and we've stopped at a whitespace
+ * character, skip to the next one, because the whitespace will
+ * be overwritten by a null byte here
+ */
+ if (**str)
+ *str += 1;
+
+ /* terminate the parsed string */
+ **target = 0;
+}
+
+/*
+ * extract the next argument from the command line
+ */
+static char *next_arg(struct uci_context *ctx, char **str, bool required)
+{
+ char *val;
+ char *ptr;
+
+ val = ptr = *str;
+ skip_whitespace(str);
+ parse_str(ctx, str, &ptr);
+ if (required && !*val) {
+ ctx->pctx->reason = "insufficient arguments";
+ ctx->pctx->byte = *str - ctx->pctx->buf;
+ UCI_THROW(ctx, UCI_ERR_PARSE);
+ }
+
+ return uci_strdup(ctx, val);
+}
+
+/*
+ * verify that the end of the line or command is reached.
+ * throw an error if extra arguments are given on the command line
+ */
+static void assert_eol(struct uci_context *ctx, char **str)
+{
+ char *tmp;
+
+ tmp = next_arg(ctx, str, false);
+ if (tmp && *tmp) {
+ ctx->pctx->reason = "too many arguments";
+ ctx->pctx->byte = tmp - ctx->pctx->buf;
+ UCI_THROW(ctx, UCI_ERR_PARSE);
+ }
+}
+
+/*
+ * switch to a different config, either triggered by uci_load, or by a
+ * 'package <...>' statement in the import file
+ */
+static void uci_switch_config(struct uci_context *ctx)
+{
+ struct uci_parse_context *pctx;
+ const char *name;
+
+ pctx = ctx->pctx;
+ name = pctx->name;
+
+ /* add the last config to main config file list */
+ if (pctx->cfg) {
+ uci_list_add(&ctx->root, &pctx->cfg->list);
+
+ pctx->cfg = NULL;
+ pctx->section = NULL;
+ }
+
+ if (!name)
+ return;
+
+ /*
+ * if an older config under the same name exists, unload it
+ * ignore errors here, e.g. if the config was not found
+ */
+ UCI_TRAP_SAVE(ctx, ignore);
+ uci_unload(ctx, name);
+ UCI_TRAP_RESTORE(ctx);
+ignore:
+ ctx->errno = 0;
+
+ pctx->cfg = uci_alloc_config(ctx, name);
+}
+
+/*
+ * parse the 'config' uci command (open a section)
+ */
+static void uci_parse_config(struct uci_context *ctx, char **str)
+{
+ char *name = NULL;
+ char *type = NULL;
+
+ if (!ctx->pctx->cfg) {
+ if (!ctx->pctx->name) {
+ ctx->pctx->byte = *str - ctx->pctx->buf;
+ ctx->pctx->reason = "attempting to import a file without a package name";
+ UCI_THROW(ctx, UCI_ERR_PARSE);
+ }
+ uci_switch_config(ctx);
+ }
+
+ /* command string null-terminated by strtok */
+ *str += strlen(*str) + 1;
+
+ UCI_TRAP_SAVE(ctx, error);
+ type = next_arg(ctx, str, true);
+ name = next_arg(ctx, str, false);
+ assert_eol(ctx, str);
+ ctx->pctx->section = uci_add_section(ctx->pctx->cfg, type, name);
+ UCI_TRAP_RESTORE(ctx);
+ return;
+
+error:
+ if (name)
+ free(name);
+ if (type)
+ free(type);
+ UCI_THROW(ctx, ctx->errno);
+}
+
+/*
+ * parse the 'option' uci command (open a value)
+ */
+static void uci_parse_option(struct uci_context *ctx, char **str)
+{
+ char *name = NULL;
+ char *value = NULL;
+
+ if (!ctx->pctx->section) {
+ ctx->pctx->byte = *str - ctx->pctx->buf;
+ ctx->pctx->reason = "option command found before the first section";
+ UCI_THROW(ctx, UCI_ERR_PARSE);
+ }
+ /* command string null-terminated by strtok */
+ *str += strlen(*str) + 1;
+
+ UCI_TRAP_SAVE(ctx, error);
+ name = next_arg(ctx, str, true);
+ value = next_arg(ctx, str, true);
+ assert_eol(ctx, str);
+ uci_add_option(ctx->pctx->section, name, value);
+ UCI_TRAP_RESTORE(ctx);
+ return;
+
+error:
+ if (name)
+ free(name);
+ if (value)
+ free(value);
+ UCI_THROW(ctx, ctx->errno);
+}
+
+
+/*
+ * parse a complete input line, split up combined commands by ';'
+ */
+static void uci_parse_line(struct uci_context *ctx)
+{
+ struct uci_parse_context *pctx = ctx->pctx;
+ char *word, *brk;
+
+ for (word = strtok_r(pctx->buf, ";", &brk);
+ word;
+ word = strtok_r(NULL, ";", &brk)) {
+
+ char *pbrk;
+ word = strtok_r(word, " \t", &pbrk);
+
+ switch(word[0]) {
+ case 'c':
+ if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
+ uci_parse_config(ctx, &word);
+ break;
+ case 'o':
+ if ((word[1] == 0) || !strcmp(word + 1, "ption"))
+ uci_parse_option(ctx, &word);
+ break;
+ default:
+ pctx->reason = "unterminated command";
+ pctx->byte = word - pctx->buf;
+ UCI_THROW(ctx, UCI_ERR_PARSE);
+ break;
+ }
+ }
+}
+
+int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_config **cfg)
+{
+ struct uci_parse_context *pctx;
+
+ /* make sure no memory from previous parse attempts is leaked */
+ uci_parse_cleanup(ctx);
+
+ pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
+ ctx->pctx = pctx;
+ pctx->file = stream;
+
+ /*
+ * If 'name' was supplied, assume that the supplied stream does not contain
+ * the appropriate 'package <name>' string to specify the config name
+ * NB: the config file can still override the package name
+ */
+ if (name)
+ pctx->name = name;
+
+ while (!feof(pctx->file)) {
+ uci_getln(ctx);
+ if (pctx->buf[0])
+ uci_parse_line(ctx);
+ }
+
+ if (cfg)
+ *cfg = pctx->cfg;
+
+ pctx->name = NULL;
+ uci_switch_config(ctx);
+
+ /* no error happened, we can get rid of the parser context now */
+ uci_parse_cleanup(ctx);
+
+ return 0;
+}
+
+int uci_load(struct uci_context *ctx, const char *name, struct uci_config **cfg)
+{
+ struct stat statbuf;
+ char *filename;
+ bool confpath;
+ FILE *file;
+
+ UCI_HANDLE_ERR(ctx);
+ UCI_ASSERT(ctx, name != NULL);
+
+ignore:
+ ctx->errno = 0;
+
+ switch (name[0]) {
+ case '.':
+ case '/':
+ /* absolute/relative path outside of /etc/config */
+ filename = (char *) name;
+ confpath = false;
+ break;
+ default:
+ filename = uci_malloc(ctx, strlen(name) + sizeof(UCI_CONFDIR) + 2);
+ sprintf(filename, UCI_CONFDIR "/%s", name);
+ confpath = true;
+ break;
+ }
+
+ if ((stat(filename, &statbuf) < 0) ||
+ ((statbuf.st_mode & S_IFMT) != S_IFREG)) {
+ UCI_THROW(ctx, UCI_ERR_NOTFOUND);
+ }
+
+ file = fopen(filename, "r");
+ if (filename != name)
+ free(filename);
+
+ if (!file)
+ UCI_THROW(ctx, UCI_ERR_IO);
+
+ return uci_import(ctx, file, name, cfg);
+}
+