userspace/libwr: added dot-config parsing

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

userspace/libwr/Makefile

 OBJS = trace.o init.o fpga_io.o util.o pps_gen.o i2c.o shw_io.o i2c_bitbang.o \
        i2c_fpga_reg.o pio.o libshw_i2c.o i2c_sfp.o fan.o i2c_io.o hwiu.o \
        ptpd_netif.o hal_client.o \
-       shmem.o hal_shmem.o rt_client.o
+       shmem.o hal_shmem.o rt_client.o \
+       dot-config.o
 
 LIB = libwr.a
 

userspace/libwr/dot-config.c

+/* Alessandro Rubini for CERN, 2014 */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <libwr/config.h>
+
+/* All strings here are strdup'd and then split; you can't free(3) them */
+struct cfg_item {
+	char *name;
+	char *value;
+	struct cfg_item *subcfg;
+	struct cfg_item *next;
+};
+
+static struct cfg_item *libwr_cfg;
+
+static int libwr_subcfg(struct cfg_item *c)
+{
+	struct cfg_item *subc;
+	c->subcfg = NULL;
+	char *rest, *s;
+
+	if (!strchr(c->value, '='))
+		return 0;
+
+	/* Very lazily, strdup this again, and then modify in place */
+	rest = strdup(c->value);
+	if (!rest)
+		return -1;
+	do {
+		subc = calloc(1, sizeof(*c));
+		if (!subc)
+			return -1;
+		subc->name = rest;
+
+		/* Trim this and save trailing text */
+		s = strchr(rest, ',');
+		if (s) {
+			rest = s + 1;
+			*s = '\0';
+		} else {
+			rest = NULL;
+		}
+
+		/* split between name and value */
+		s = strchr(subc->name, '=');
+		if (s) {
+			subc->value = s + 1;
+			*s = '\0';
+		}
+
+		/* store and continue, if more is there */
+		subc->next = c->subcfg;
+		c->subcfg = subc;
+	} while (rest);
+	return 0;
+}
+
+/* Parse a line into name=value and subcfg. Assume dot-config format */
+static int libwr_cfg_line(char *line)
+{
+	struct cfg_item *c;
+	char name[512], value[512];
+
+	if (line[0] == '#')
+		return 0;
+	if (strlen(line) < 2)
+		return 0;
+
+	if (sscanf(line, "CONFIG_%[^=]=%[^\n]", name, value) != 2) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	c = malloc(sizeof(*c));
+	if (!c)
+		return -1;
+	c->subcfg = NULL;
+	c->name = strdup(name);
+	c->value = strdup(value);
+	if (!c->name || !c->value)
+		return -1;
+
+	/* Strip quotes */
+	if (c->value[0] == '"')
+		c->value++;
+	if (c->value[strlen(c->value) - 1] == '"')
+		c->value[strlen(c->value) - 1] = '\0';
+
+	libwr_subcfg(c);
+
+	c->next = libwr_cfg;
+	libwr_cfg = c;
+	return 0;
+}
+
+int libwr_cfg_read_file(char *dotconfig)
+{
+	char s[512];
+	FILE *f;
+	int lineno = 0;
+
+	f = fopen(dotconfig, "r");
+	if (!f)
+		return -1;
+
+	while (fgets(s, sizeof(s), f)) {
+		lineno++;
+		if (libwr_cfg_line(s) < 0)
+			return -lineno;
+	}
+	fclose(f);
+	return 0;
+}
+
+int libwr_cfg_dump(FILE *output)
+{
+	struct cfg_item *c = libwr_cfg;
+	struct cfg_item *subc = libwr_cfg;
+
+	while (c) {
+		fprintf(output, "name=\"%s\"\n  value=\"%s\"\n",
+			c->name, c->value);
+		subc = c->subcfg;
+		while (subc) {
+			fprintf(output, "    name=\"%s\"\n"
+				"      value=\"%s\"\n",
+				subc->name, subc->value);
+			subc = subc->next;
+		}
+		c = c->next;
+	}
+	return 0;
+}
+
+int libwr_cfg_read_verify_file(char *dotconfig, char *kconfig)
+{
+	FILE *f;
+	int errors = 0;
+	char s[256], name[256];
+	struct cfg_item *c;
+
+	struct kc {
+		char *name;
+		struct kc *next;
+	} *all_configs = NULL, *kc, *next;
+
+	if (libwr_cfg_read_file(dotconfig))
+		return -1;
+
+	/* Read Kconfig and store all config names */
+	f = fopen(kconfig, "r");
+	if (!f)
+		return -1;
+	while (fgets(s, sizeof(s), f)) {
+		if (sscanf(s, "config %s", name) != 1)
+			continue;
+		kc = malloc(sizeof(*kc));
+		if (!kc)
+			return -1;
+		kc->name = strdup(name);
+		kc->next = all_configs;
+		all_configs = kc;
+	}
+	fclose(f);
+
+	/* Verify all configs, complain if missing */
+	for (c = libwr_cfg; c; c = c->next) {
+		for (kc = all_configs; kc; kc = kc->next)
+			if (!strcmp(c->name, kc->name))
+				break;
+		if (!kc) {
+			fprintf(stderr, "Configuration \"%s\" not found\n",
+				c->name);
+			errors++;
+		}
+	}
+
+	/* Free all kconfig allocs */
+	for (kc = all_configs; kc; kc = next) {
+		next = kc->next;
+		free(kc->name);
+		free(kc);
+	}
+	if (errors) {
+		errno = EINVAL;
+		return -1;
+	}
+	return 0;
+}
+
+char *libwr_cfg_get(char *cfgname)
+{
+	struct cfg_item *c;
+
+	for (c = libwr_cfg; c; c = c->next)
+		if (!strcmp(cfgname, c->name))
+			return c->value;
+	return NULL;
+}
+
+char *libwr_cfg_get2(char *cfgname, char *subname)
+{
+	struct cfg_item *c, *subc;
+
+	for (c = libwr_cfg; c; c = c->next)
+		if (!strcmp(cfgname, c->name)) {
+			for (subc = c->subcfg; subc; subc = subc->next)
+				if (!strcmp(subname, subc->name))
+					return subc->value;
+		}
+	return NULL;
+}
+
+int libwr_cfg_convert2(char *cfgname, char *subname,
+			 enum libwr_convert conv, void *ret, ...)
+{
+	double *dptr = ret;
+	int *iptr = ret;
+	char real_cfgname[128];
+	char *value;
+	va_list args;
+	char ch;
+
+	va_start(args, ret);
+	vsprintf(real_cfgname, cfgname, args);
+	va_end(args);
+
+	value = libwr_cfg_get2(real_cfgname, subname);
+	if (!value) {
+		errno = ENOENT;
+		return -1;
+	}
+	errno = EINVAL;
+	switch(conv) {
+	case LIBWR_INT:
+		if (sscanf(value, "%i%c", iptr, &ch) != 1)
+			return -1;
+		return 0;
+	case LIBWR_STRING:
+		strcpy(ret, value);
+		return 0;
+	case LIBWR_DOUBLE:
+		if (sscanf(value, "%lf%c", dptr, &ch) != 1)
+			return -1;
+		return 0;
+	}
+	return -1; /* never */
+}

userspace/libwr/include/libwr/config.h

+#ifndef __LIBWR_CONFIG_H__
+#define __LIBWR_CONFIG_H__
+
+/* Read a dot-config file, return 0 or -line, the unparsable line in file */
+int libwr_cfg_read_file(char *dotconfig);
+
+/* Diagnostic tool */
+int libwr_cfg_dump(FILE *output);
+
+/* Read a dot-config, verifying with Kconfig to complain for wrong names */
+int libwr_cfg_read_verify_file(char *dotconfig, char *kconfig);
+
+/* cfg_get() works for CONFIG_NTP_SERVER. Returns NULL or static storage. */
+char *libwr_cfg_get(char *cfgname);
+
+/* cfg_get2(), as above but with suboptions like "name=AXGE-3454-0531". */
+char *libwr_cfg_get2(char *cfgname, char *subname);
+
+/* We only convert the following types */
+enum libwr_convert {
+	LIBWR_INT,
+	LIBWR_STRING,
+	LIBWR_DOUBLE,
+};
+
+/*
+ * The following is the most flexible one: subname can be NULL,
+ * and the cfgname is a printf-format string (e.g. "PORT%02i_PARAMS");
+ * finally, the value is sscanf'd in the library, with error check.
+ * Returns 0 or -1 with errno set to EINVAL.
+ */
+int libwr_cfg_convert2(char *cfgname, char *subname,
+			   enum libwr_convert, void *ret, ...)
+	__attribute__((format(printf, 1, 5)));
+
+#endif /* __LIBWR_CONFIG_H__ */