Add a new "ini" command

This allows you to read ini-formatted data from anywhere and then
import one of the sections into the environment

This is based on rev 16 at http://code.google.com/p/inih/

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/common/Makefile b/common/Makefile
index 125b2be..92e06de 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -107,6 +107,7 @@
 COBJS-$(CONFIG_CMD_I2C) += cmd_i2c.o
 COBJS-$(CONFIG_CMD_IDE) += cmd_ide.o
 COBJS-$(CONFIG_CMD_IMMAP) += cmd_immap.o
+COBJS-$(CONFIG_CMD_INI) += cmd_ini.o
 COBJS-$(CONFIG_CMD_IRQ) += cmd_irq.o
 COBJS-$(CONFIG_CMD_ITEST) += cmd_itest.o
 COBJS-$(CONFIG_CMD_JFFS2) += cmd_jffs2.o
diff --git a/common/cmd_ini.c b/common/cmd_ini.c
new file mode 100644
index 0000000..652e4f6
--- /dev/null
+++ b/common/cmd_ini.c
@@ -0,0 +1,247 @@
+/*
+ * inih -- simple .INI file parser
+ *
+ * inih is released under the New BSD license (see LICENSE.txt). Go to the
+ * project home page for more info:
+ *
+ * http://code.google.com/p/inih/
+ */
+
+#include <common.h>
+#include <command.h>
+#include <environment.h>
+#include <linux/ctype.h>
+#include <linux/string.h>
+
+#ifdef CONFIG_INI_MAX_LINE
+#define MAX_LINE CONFIG_INI_MAX_LINE
+#else
+#define MAX_LINE 200
+#endif
+
+#ifdef CONFIG_INI_MAX_SECTION
+#define MAX_SECTION CONFIG_INI_MAX_SECTION
+#else
+#define MAX_SECTION 50
+#endif
+
+#ifdef CONFIG_INI_MAX_NAME
+#define MAX_NAME CONFIG_INI_MAX_NAME
+#else
+#define MAX_NAME 50
+#endif
+
+/* Strip whitespace chars off end of given string, in place. Return s. */
+static char *rstrip(char *s)
+{
+	char *p = s + strlen(s);
+
+	while (p > s && isspace(*--p))
+		*p = '\0';
+	return s;
+}
+
+/* Return pointer to first non-whitespace char in given string. */
+static char *lskip(const char *s)
+{
+	while (*s && isspace(*s))
+		s++;
+	return (char *)s;
+}
+
+/* Return pointer to first char c or ';' comment in given string, or pointer to
+   null at end of string if neither found. ';' must be prefixed by a whitespace
+   character to register as a comment. */
+static char *find_char_or_comment(const char *s, char c)
+{
+	int was_whitespace = 0;
+
+	while (*s && *s != c && !(was_whitespace && *s == ';')) {
+		was_whitespace = isspace(*s);
+		s++;
+	}
+	return (char *)s;
+}
+
+/* Version of strncpy that ensures dest (size bytes) is null-terminated. */
+static char *strncpy0(char *dest, const char *src, size_t size)
+{
+	strncpy(dest, src, size);
+	dest[size - 1] = '\0';
+	return dest;
+}
+
+/* Emulate the behavior of fgets but on memory */
+static char *memgets(char *str, int num, char **mem, size_t *memsize)
+{
+	char *end;
+	int len;
+	int newline = 1;
+
+	end = memchr(*mem, '\n', *memsize);
+	if (end == NULL) {
+		if (*memsize == 0)
+			return NULL;
+		end = *mem + *memsize;
+		newline = 0;
+	}
+	len = min((end - *mem) + newline, num);
+	memcpy(str, *mem, len);
+	if (len < num)
+		str[len] = '\0';
+
+	/* prepare the mem vars for the next call */
+	*memsize -= (end - *mem) + newline;
+	*mem += (end - *mem) + newline;
+
+	return str;
+}
+
+/* Parse given INI-style file. May have [section]s, name=value pairs
+   (whitespace stripped), and comments starting with ';' (semicolon). Section
+   is "" if name=value pair parsed before any section heading. name:value
+   pairs are also supported as a concession to Python's ConfigParser.
+
+   For each name=value pair parsed, call handler function with given user
+   pointer as well as section, name, and value (data only valid for duration
+   of handler call). Handler should return nonzero on success, zero on error.
+
+   Returns 0 on success, line number of first error on parse error (doesn't
+   stop on first error).
+*/
+static int ini_parse(char *filestart, size_t filelen,
+	int (*handler)(void *, char *, char *, char *),	void *user)
+{
+	/* Uses a fair bit of stack (use heap instead if you need to) */
+	char line[MAX_LINE];
+	char section[MAX_SECTION] = "";
+	char prev_name[MAX_NAME] = "";
+
+	char *curmem = filestart;
+	char *start;
+	char *end;
+	char *name;
+	char *value;
+	size_t memleft = filelen;
+	int lineno = 0;
+	int error = 0;
+
+	/* Scan through file line by line */
+	while (memgets(line, sizeof(line), &curmem, &memleft) != NULL) {
+		lineno++;
+		start = lskip(rstrip(line));
+
+		if (*start == ';' || *start == '#') {
+			/*
+			 * Per Python ConfigParser, allow '#' comments at start
+			 * of line
+			 */
+		}
+#if CONFIG_INI_ALLOW_MULTILINE
+		else if (*prev_name && *start && start > line) {
+			/*
+			 * Non-blank line with leading whitespace, treat as
+			 * continuation of previous name's value (as per Python
+			 * ConfigParser).
+			 */
+			if (!handler(user, section, prev_name, start) && !error)
+				error = lineno;
+		}
+#endif
+		else if (*start == '[') {
+			/* A "[section]" line */
+			end = find_char_or_comment(start + 1, ']');
+			if (*end == ']') {
+				*end = '\0';
+				strncpy0(section, start + 1, sizeof(section));
+				*prev_name = '\0';
+			} else if (!error) {
+				/* No ']' found on section line */
+				error = lineno;
+			}
+		} else if (*start && *start != ';') {
+			/* Not a comment, must be a name[=:]value pair */
+			end = find_char_or_comment(start, '=');
+			if (*end != '=')
+				end = find_char_or_comment(start, ':');
+			if (*end == '=' || *end == ':') {
+				*end = '\0';
+				name = rstrip(start);
+				value = lskip(end + 1);
+				end = find_char_or_comment(value, '\0');
+				if (*end == ';')
+					*end = '\0';
+				rstrip(value);
+				/* Strip double-quotes */
+				if (value[0] == '"' &&
+				    value[strlen(value)-1] == '"') {
+					value[strlen(value)-1] = '\0';
+					value += 1;
+				}
+
+				/*
+				 * Valid name[=:]value pair found, call handler
+				 */
+				strncpy0(prev_name, name, sizeof(prev_name));
+				if (!handler(user, section, name, value) &&
+				     !error)
+					error = lineno;
+			} else if (!error)
+				/* No '=' or ':' found on name[=:]value line */
+				error = lineno;
+		}
+	}
+
+	return error;
+}
+
+static int ini_handler(void *user, char *section, char *name, char *value)
+{
+	char *requested_section = (char *)user;
+#ifdef CONFIG_INI_CASE_INSENSITIVE
+	int i;
+
+	for (i = 0; i < strlen(requested_section); i++)
+		requested_section[i] = tolower(requested_section[i]);
+	for (i = 0; i < strlen(section); i++)
+		section[i] = tolower(section[i]);
+#endif
+
+	if (!strcmp(section, requested_section)) {
+#ifdef CONFIG_INI_CASE_INSENSITIVE
+		for (i = 0; i < strlen(name); i++)
+			name[i] = tolower(name[i]);
+		for (i = 0; i < strlen(value); i++)
+			value[i] = tolower(value[i]);
+#endif
+		setenv(name, value);
+		printf("ini: Imported %s as %s\n", name, value);
+	}
+
+	/* success */
+	return 1;
+}
+
+static int do_ini(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	const char *section;
+	char *file_address;
+	size_t file_size;
+
+	if (argc == 1)
+		return CMD_RET_USAGE;
+
+	section = argv[1];
+	file_address = (char *)simple_strtoul(
+		argc < 3 ? getenv("loadaddr") : argv[2], NULL, 16);
+	file_size = (size_t)simple_strtoul(
+		argc < 4 ? getenv("filesize") : argv[3], NULL, 16);
+
+	return ini_parse(file_address, file_size, ini_handler, (void *)section);
+}
+
+U_BOOT_CMD(
+	ini, 4, 0, do_ini,
+	"parse an ini file in memory and merge the specified section into the env",
+	"section [[file-address] file-size]"
+);