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Diffstat (limited to 'common/env_flags.c')
| -rw-r--r-- | common/env_flags.c | 560 |
1 files changed, 560 insertions, 0 deletions
diff --git a/common/env_flags.c b/common/env_flags.c new file mode 100644 index 0000000..336cae4 --- /dev/null +++ b/common/env_flags.c @@ -0,0 +1,560 @@ +/* + * (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> + +#ifdef USE_HOSTCC /* Eliminate "ANSI does not permit..." warnings */ +#include <stdint.h> +#include <stdio.h> +#include "fw_env.h" +#include <env_attr.h> +#include <env_flags.h> +#define getenv fw_getenv +#else +#include <common.h> +#include <environment.h> +#endif + +#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; +static const char env_flags_varaccess_rep[] = "aroc"; +static const int env_flags_varaccess_mask[] = { + 0, + ENV_FLAGS_VARACCESS_PREVENT_DELETE | + ENV_FLAGS_VARACCESS_PREVENT_CREATE | + ENV_FLAGS_VARACCESS_PREVENT_OVERWR, + ENV_FLAGS_VARACCESS_PREVENT_DELETE | + ENV_FLAGS_VARACCESS_PREVENT_OVERWR, + ENV_FLAGS_VARACCESS_PREVENT_DELETE | + ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR}; + +#ifdef CONFIG_CMD_ENV_FLAGS +static const char * const env_flags_vartype_names[] = { + "string", + "decimal", + "hexadecimal", + "boolean", +#ifdef CONFIG_CMD_NET + "IP address", + "MAC address", +#endif +}; +static const char * const env_flags_varaccess_names[] = { + "any", + "read-only", + "write-once", + "change-default", +}; + +/* + * Print the whole list of available type flags. + */ +void env_flags_print_vartypes(void) +{ + enum env_flags_vartype curtype = (enum env_flags_vartype)0; + + while (curtype != env_flags_vartype_end) { + printf("\t%c -\t%s\n", env_flags_vartype_rep[curtype], + env_flags_vartype_names[curtype]); + curtype++; + } +} + +/* + * Print the whole list of available access flags. + */ +void env_flags_print_varaccess(void) +{ + enum env_flags_varaccess curaccess = (enum env_flags_varaccess)0; + + while (curaccess != env_flags_varaccess_end) { + printf("\t%c -\t%s\n", env_flags_varaccess_rep[curaccess], + env_flags_varaccess_names[curaccess]); + curaccess++; + } +} + +/* + * Return the name of the type. + */ +const char *env_flags_get_vartype_name(enum env_flags_vartype type) +{ + return env_flags_vartype_names[type]; +} + +/* + * Return the name of the access. + */ +const char *env_flags_get_varaccess_name(enum env_flags_varaccess access) +{ + return env_flags_varaccess_names[access]; +} +#endif /* CONFIG_CMD_ENV_FLAGS */ + +/* + * 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; +} + +/* + * Parse the flags string from a .flags attribute list into the varaccess enum. + */ +enum env_flags_varaccess env_flags_parse_varaccess(const char *flags) +{ + char *access; + + if (strlen(flags) <= ENV_FLAGS_VARACCESS_LOC) + return env_flags_varaccess_any; + + access = strchr(env_flags_varaccess_rep, + flags[ENV_FLAGS_VARACCESS_LOC]); + + if (access != NULL) + return (enum env_flags_varaccess) + (access - &env_flags_varaccess_rep[0]); + + printf("## Warning: Unknown environment variable access method '%c'\n", + flags[ENV_FLAGS_VARACCESS_LOC]); + return env_flags_varaccess_any; +} + +/* + * Parse the binary flags from a hash table entry into the varaccess enum. + */ +enum env_flags_varaccess env_flags_parse_varaccess_from_binflags(int binflags) +{ + int i; + + for (i = 0; i < sizeof(env_flags_varaccess_mask); i++) + if (env_flags_varaccess_mask[i] == + (binflags & ENV_FLAGS_VARACCESS_BIN_MASK)) + return (enum env_flags_varaccess)i; + + printf("Warning: Non-standard access flags. (0x%x)\n", + binflags & ENV_FLAGS_VARACCESS_BIN_MASK); + + return env_flags_varaccess_any; +} + +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; +} + +#ifdef USE_HOSTCC /* Functions only used from tools/env */ +/* + * Look up any flags directly from the .flags variable and the static list + * and convert them to the vartype enum. + */ +enum env_flags_vartype env_flags_get_type(const char *name) +{ + const char *flags_list = getenv(ENV_FLAGS_VAR); + char flags[ENV_FLAGS_ATTR_MAX_LEN + 1]; + + if (env_flags_lookup(flags_list, name, flags)) + return env_flags_vartype_string; + + if (strlen(flags) <= ENV_FLAGS_VARTYPE_LOC) + return env_flags_vartype_string; + + return env_flags_parse_vartype(flags); +} + +/* + * Look up the access of a variable directly from the .flags var. + */ +enum env_flags_varaccess env_flags_get_varaccess(const char *name) +{ + const char *flags_list = getenv(ENV_FLAGS_VAR); + char flags[ENV_FLAGS_ATTR_MAX_LEN + 1]; + + if (env_flags_lookup(flags_list, name, flags)) + return env_flags_varaccess_any; + + if (strlen(flags) <= ENV_FLAGS_VARACCESS_LOC) + return env_flags_varaccess_any; + + return env_flags_parse_varaccess(flags); +} + +/* + * Validate that the proposed new value for "name" is valid according to the + * defined flags for that variable, if any. + */ +int env_flags_validate_type(const char *name, const char *value) +{ + enum env_flags_vartype type; + + if (value == NULL) + return 0; + type = env_flags_get_type(name); + if (_env_flags_validate_type(value, type) < 0) { + printf("## Error: flags type check failure for " + "\"%s\" <= \"%s\" (type: %c)\n", + name, value, env_flags_vartype_rep[type]); + return -1; + } + return 0; +} + +/* + * Validate that the proposed access to variable "name" is valid according to + * the defined flags for that variable, if any. + */ +int env_flags_validate_varaccess(const char *name, int check_mask) +{ + enum env_flags_varaccess access; + int access_mask; + + access = env_flags_get_varaccess(name); + access_mask = env_flags_varaccess_mask[access]; + + return (check_mask & access_mask) != 0; +} + +/* + * Validate the parameters to "env set" directly + */ +int env_flags_validate_env_set_params(int argc, char * const argv[]) +{ + if ((argc >= 3) && argv[2] != NULL) { + enum env_flags_vartype type = env_flags_get_type(argv[1]); + + /* + * we don't currently check types that need more than + * one argument + */ + if (type != env_flags_vartype_string && argc > 3) { + printf("## Error: too many parameters for setting " + "\"%s\"\n", argv[1]); + return -1; + } + return env_flags_validate_type(argv[1], argv[2]); + } + /* ok */ + return 0; +} + +#else /* !USE_HOSTCC - Functions only used from lib/hashtable.c */ + +/* + * 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) +{ + int binflags; + + binflags = env_flags_parse_vartype(flags) & ENV_FLAGS_VARTYPE_BIN_MASK; + binflags |= env_flags_varaccess_mask[env_flags_parse_varaccess(flags)]; + + return binflags; +} + +/* + * 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; + const char *oldval = NULL; + + if (op != env_op_create) + oldval = item->data; + + name = item->key; + + /* Default value for NULL to protect string-manipulating functions */ + newval = newval ? : ""; + + /* 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; + } + } + + /* check for access permission */ +#ifndef CONFIG_ENV_ACCESS_IGNORE_FORCE + if (flag & H_FORCE) + return 0; +#endif + switch (op) { + case env_op_delete: + if (item->flags & ENV_FLAGS_VARACCESS_PREVENT_DELETE) { + printf("## Error: Can't delete \"%s\"\n", name); + return 1; + } + break; + case env_op_overwrite: + if (item->flags & ENV_FLAGS_VARACCESS_PREVENT_OVERWR) { + printf("## Error: Can't overwrite \"%s\"\n", name); + return 1; + } else if (item->flags & + ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR) { + const char *defval = getenv_default(name); + + if (defval == NULL) + defval = ""; + printf("oldval: %s defval: %s\n", oldval, defval); + if (strcmp(oldval, defval) != 0) { + printf("## Error: Can't overwrite \"%s\"\n", + name); + return 1; + } + } + break; + case env_op_create: + if (item->flags & ENV_FLAGS_VARACCESS_PREVENT_CREATE) { + printf("## Error: Can't create \"%s\"\n", name); + return 1; + } + break; + } + + return 0; +} + +#endif |