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Diffstat (limited to 'common/env_flags.c')
| -rw-r--r-- | common/env_flags.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/common/env_flags.c b/common/env_flags.c new file mode 100644 index 000000000..a58d614bb --- /dev/null +++ b/common/env_flags.c @@ -0,0 +1,319 @@ +/* + * (C) Copyright 2012 + * Joe Hershberger, National Instruments, joe.hershberger@ni.com + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <linux/string.h> +#include <linux/ctype.h> + +#include <common.h> +#include <environment.h> + +#ifdef CONFIG_CMD_NET +#define ENV_FLAGS_NET_VARTYPE_REPS "im" +#else +#define ENV_FLAGS_NET_VARTYPE_REPS "" +#endif + +static const char env_flags_vartype_rep[] = "sdxb" ENV_FLAGS_NET_VARTYPE_REPS; + +/* + * Parse the flags string from a .flags attribute list into the vartype enum. + */ +enum env_flags_vartype env_flags_parse_vartype(const char *flags) +{ + char *type; + + if (strlen(flags) <= ENV_FLAGS_VARTYPE_LOC) + return env_flags_vartype_string; + + type = strchr(env_flags_vartype_rep, + flags[ENV_FLAGS_VARTYPE_LOC]); + + if (type != NULL) + return (enum env_flags_vartype) + (type - &env_flags_vartype_rep[0]); + + printf("## Warning: Unknown environment variable type '%c'\n", + flags[ENV_FLAGS_VARTYPE_LOC]); + return env_flags_vartype_string; +} + +static inline int is_hex_prefix(const char *value) +{ + return value[0] == '0' && (value[1] == 'x' || value[1] == 'X'); +} + +static void skip_num(int hex, const char *value, const char **end, + int max_digits) +{ + int i; + + if (hex && is_hex_prefix(value)) + value += 2; + + for (i = max_digits; i != 0; i--) { + if (hex && !isxdigit(*value)) + break; + if (!hex && !isdigit(*value)) + break; + value++; + } + if (end != NULL) + *end = value; +} + +/* + * Based on the declared type enum, validate that the value string complies + * with that format + */ +static int _env_flags_validate_type(const char *value, + enum env_flags_vartype type) +{ + const char *end; +#ifdef CONFIG_CMD_NET + const char *cur; + int i; +#endif + + switch (type) { + case env_flags_vartype_string: + break; + case env_flags_vartype_decimal: + skip_num(0, value, &end, -1); + if (*end != '\0') + return -1; + break; + case env_flags_vartype_hex: + skip_num(1, value, &end, -1); + if (*end != '\0') + return -1; + if (value + 2 == end && is_hex_prefix(value)) + return -1; + break; + case env_flags_vartype_bool: + if (value[0] != '1' && value[0] != 'y' && value[0] != 't' && + value[0] != 'Y' && value[0] != 'T' && + value[0] != '0' && value[0] != 'n' && value[0] != 'f' && + value[0] != 'N' && value[0] != 'F') + return -1; + if (value[1] != '\0') + return -1; + break; +#ifdef CONFIG_CMD_NET + case env_flags_vartype_ipaddr: + cur = value; + for (i = 0; i < 4; i++) { + skip_num(0, cur, &end, 3); + if (cur == end) + return -1; + if (i != 3 && *end != '.') + return -1; + if (i == 3 && *end != '\0') + return -1; + cur = end + 1; + } + break; + case env_flags_vartype_macaddr: + cur = value; + for (i = 0; i < 6; i++) { + skip_num(1, cur, &end, 2); + if (cur == end) + return -1; + if (cur + 2 == end && is_hex_prefix(cur)) + return -1; + if (i != 5 && *end != ':') + return -1; + if (i == 5 && *end != '\0') + return -1; + cur = end + 1; + } + break; +#endif + case env_flags_vartype_end: + return -1; + } + + /* OK */ + return 0; +} + +/* + * Look for flags in a provided list and failing that the static list + */ +static inline int env_flags_lookup(const char *flags_list, const char *name, + char *flags) +{ + int ret = 1; + + if (!flags) + /* bad parameter */ + return -1; + + /* try the env first */ + if (flags_list) + ret = env_attr_lookup(flags_list, name, flags); + + if (ret != 0) + /* if not found in the env, look in the static list */ + ret = env_attr_lookup(ENV_FLAGS_LIST_STATIC, name, flags); + + return ret; +} + +/* + * Parse the flag charachters from the .flags attribute list into the binary + * form to be stored in the environment entry->flags field. + */ +static int env_parse_flags_to_bin(const char *flags) +{ + return env_flags_parse_vartype(flags) & ENV_FLAGS_VARTYPE_BIN_MASK; +} + +/* + * Look for possible flags for a newly added variable + * This is called specifically when the variable did not exist in the hash + * previously, so the blanket update did not find this variable. + */ +void env_flags_init(ENTRY *var_entry) +{ + const char *var_name = var_entry->key; + const char *flags_list = getenv(ENV_FLAGS_VAR); + char flags[ENV_FLAGS_ATTR_MAX_LEN + 1] = ""; + int ret = 1; + + /* look in the ".flags" and static for a reference to this variable */ + ret = env_flags_lookup(flags_list, var_name, flags); + + /* if any flags were found, set the binary form to the entry */ + if (!ret && strlen(flags)) + var_entry->flags = env_parse_flags_to_bin(flags); +} + +/* + * Called on each existing env var prior to the blanket update since removing + * a flag in the flag list should remove its flags. + */ +static int clear_flags(ENTRY *entry) +{ + entry->flags = 0; + + return 0; +} + +/* + * Call for each element in the list that defines flags for a variable + */ +static int set_flags(const char *name, const char *value) +{ + ENTRY e, *ep; + + e.key = name; + e.data = NULL; + hsearch_r(e, FIND, &ep, &env_htab, 0); + + /* does the env variable actually exist? */ + if (ep != NULL) { + /* the flag list is empty, so clear the flags */ + if (value == NULL || strlen(value) == 0) + ep->flags = 0; + else + /* assign the requested flags */ + ep->flags = env_parse_flags_to_bin(value); + } + + return 0; +} + +static int on_flags(const char *name, const char *value, enum env_op op, + int flags) +{ + /* remove all flags */ + hwalk_r(&env_htab, clear_flags); + + /* configure any static flags */ + env_attr_walk(ENV_FLAGS_LIST_STATIC, set_flags); + /* configure any dynamic flags */ + env_attr_walk(value, set_flags); + + return 0; +} +U_BOOT_ENV_CALLBACK(flags, on_flags); + +/* + * Perform consistency checking before creating, overwriting, or deleting an + * environment variable. Called as a callback function by hsearch_r() and + * hdelete_r(). Returns 0 in case of success, 1 in case of failure. + * When (flag & H_FORCE) is set, do not print out any error message and force + * overwriting of write-once variables. + */ + +int env_flags_validate(const ENTRY *item, const char *newval, enum env_op op, + int flag) +{ + const char *name; +#if !defined(CONFIG_ENV_OVERWRITE) && defined(CONFIG_OVERWRITE_ETHADDR_ONCE) \ +&& defined(CONFIG_ETHADDR) + const char *oldval = NULL; + + if (op != env_op_create) + oldval = item->data; +#endif + + name = item->key; + + /* Default value for NULL to protect string-manipulating functions */ + newval = newval ? : ""; + +#ifndef CONFIG_ENV_OVERWRITE + /* + * Some variables like "ethaddr" and "serial#" can be set only once and + * cannot be deleted, unless CONFIG_ENV_OVERWRITE is defined. + */ + if (op != env_op_create && /* variable exists */ + (flag & H_FORCE) == 0) { /* and we are not forced */ + if (strcmp(name, "serial#") == 0 || + (strcmp(name, "ethaddr") == 0 +#if defined(CONFIG_OVERWRITE_ETHADDR_ONCE) && defined(CONFIG_ETHADDR) + && strcmp(oldval, __stringify(CONFIG_ETHADDR)) != 0 +#endif /* CONFIG_OVERWRITE_ETHADDR_ONCE && CONFIG_ETHADDR */ + )) { + printf("Can't overwrite \"%s\"\n", name); + return 1; + } + } +#endif + + /* validate the value to match the variable type */ + if (op != env_op_delete) { + enum env_flags_vartype type = (enum env_flags_vartype) + (ENV_FLAGS_VARTYPE_BIN_MASK & item->flags); + + if (_env_flags_validate_type(newval, type) < 0) { + printf("## Error: flags type check failure for " + "\"%s\" <= \"%s\" (type: %c)\n", + name, newval, env_flags_vartype_rep[type]); + return -1; + } + } + + return 0; +} |