Matching board via DMI

If a board is not uniquely identifiable by PCI device/subsystem IDs, a
string can be specified to be looked for (case-sensitive, substring or
anchored) for now in one of the following DMI items in addition to matching
the PCI IDs:
 - System Manufacturer
 - System Product Name
 - System Version
 - Baseboard Manufacturer
 - Baseboard Product Name
 - Baseboard Version

Strings are anchored re-like (^ at the beginning, $ at the end), but
there are no plans to support full regular expressions and matched to any
of the mentioned fields.

The match is only made if DMI info is available and the string matches.
If no DMI info is available and the PCI IDs match, a warning is printed
as the board can not be autodetected.

It's still open to discussion whether we add an DMI override switch to
specify a string that will definitely match, and whether this switch is
only used if no DMI is available or whether it overrides or augments DMI
data.

DMI data is currently read using dmidecode. This tool is available for
all major platforms except MacOS X. I heard that there also is a MacOS X
version of dmidecode, but didn't investigate that.

Signed-off-by: Michael Karcher <flashrom@mkarcher.dialup.fu-berlin.de>
Acked-by: Luc Verhaegen <libv@skynet.be>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>

git-svn-id: https://code.coreboot.org/svn/flashrom/trunk@874 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

1 files changed, 168 insertions, 0 deletions

diff --git a/dmi.c b/dmi.c
new file mode 100644
index 0000000..ca75461
--- /dev/null
+++ b/dmi.c
@@ -0,0 +1,168 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2009,2010 Michael Karcher
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "flash.h"
+
+enum dmi_strings {
+	DMI_SYS_MANUFACTURER,
+	DMI_SYS_PRODUCT,
+	DMI_SYS_VERSION,
+	DMI_BB_MANUFACTURER,
+	DMI_BB_PRODUCT,
+	DMI_BB_VERSION,
+	DMI_ID_INVALID /* This must always be the last entry */
+};
+
+/* The short_id for baseboard starts with "m" as in mainboard to leave
+   "b" available for BIOS */
+struct {
+	const char *dmidecode_name;
+	char short_id[3];
+} dmi_properties[DMI_ID_INVALID] = {
+	{"system-manufacturer", "sm"},
+	{"system-product-name", "sp"},
+	{"system-version", "sv"},
+	{"baseboard-manufacturer", "mm"},
+	{"baseboard-product-name", "mp"},
+	{"baseboard-version", "mv"}
+};
+
+#define DMI_COMMAND_LEN_MAX 260
+const char *dmidecode_command = "dmidecode";
+
+int has_dmi_support = 0;
+char *dmistrings[DMI_ID_INVALID];
+
+/* strings longer than 4096 in DMI are just insane */
+#define DMI_MAX_ANSWER_LEN 4096
+
+void dmi_init(void)
+{
+	FILE *dmidecode_pipe;
+	int i;
+	char *answerbuf = malloc(DMI_MAX_ANSWER_LEN);
+	if(!answerbuf)
+	{
+		fprintf(stderr, "DMI: couldn't alloc answer buffer\n");
+		return;
+	}
+	for (i = 0; i < DMI_ID_INVALID; i++)
+	{
+		char commandline[DMI_COMMAND_LEN_MAX+40];
+		snprintf(commandline, sizeof(commandline),
+		         "%s -s %s", dmidecode_command,
+		         dmi_properties[i].dmidecode_name);
+		dmidecode_pipe = popen(commandline, "r");
+		if (!dmidecode_pipe)
+		{
+			printf_debug("DMI pipe open error\n");
+			goto out_free;
+		}
+		fgets(answerbuf, DMI_MAX_ANSWER_LEN, dmidecode_pipe);
+		if (ferror(dmidecode_pipe))
+		{
+			printf_debug("DMI pipe read error\n");
+			pclose(dmidecode_pipe);
+			goto out_free;
+		}
+		/* Toss all output above DMI_MAX_ANSWER_LEN away to prevent
+		   deadlock on pclose. */
+		while (!feof(dmidecode_pipe))
+			getc(dmidecode_pipe);
+		if (pclose(dmidecode_pipe) != 0)
+		{
+			printf_debug("DMI pipe close error\n");
+			goto out_free;
+		}
+
+		/* chomp trailing newline */
+		if (answerbuf[0] != 0 &&
+		    answerbuf[strlen(answerbuf) - 1] == '\n')
+			answerbuf[strlen(answerbuf) - 1] = 0;
+		printf_debug("DMI string %d: \"%s\"\n", i, answerbuf);
+		dmistrings[i] = strdup(answerbuf);
+	}
+	has_dmi_support = 1;
+out_free:
+	free(answerbuf);
+}
+
+/**
+ * Does an substring/prefix/postfix/whole-string match.
+ *
+ * The pattern is matched as-is. The only metacharacters supported are '^'
+ * at the beginning and '$' at the end. So you can look for "^prefix",
+ * "suffix$", "substring" or "^complete string$".
+ *
+ * @param value The string to check.
+ * @param pattern The pattern.
+ * @return Nonzero if pattern matches.
+ */
+static int dmi_compare(const char *value, const char *pattern)
+{
+	int anchored = 0;
+	int patternlen;
+	printf_debug("matching %s against %s\n", value, pattern);
+	/* The empty string is part of all strings */
+	if (pattern[0] == 0)
+		return 1;
+
+	if (pattern[0] == '^') {
+		anchored = 1;
+		pattern++;
+	}
+
+	patternlen = strlen(pattern);
+	if (pattern[patternlen - 1] == '$') {
+		int valuelen = strlen(value);
+		patternlen--;
+		if(patternlen > valuelen)
+			return 0;
+
+		/* full string match: require same length */
+		if(anchored && (valuelen != patternlen))
+			return 0;
+
+		/* start character to make ends match */
+		value += valuelen - patternlen;
+		anchored = 1;
+	}
+
+	if (anchored)
+		return strncmp(value, pattern, patternlen) == 0;
+	else
+		return strstr(value, pattern) != NULL;
+}
+
+int dmi_match(const char *pattern)
+{
+	int i;
+	if (!has_dmi_support)
+		return 0;
+
+	for (i = 0;i < DMI_ID_INVALID; i++)
+		return dmi_compare(dmistrings[i], pattern);
+
+	return 0;
+}