Add another custom environment flag which discerns environment coming from external storage from environment set by U-Boot itself.

Signed-off-by: Marek Vasut marex@denx.de --- V2: New patch --- env/common.c | 13 +++++++------ env/eeprom.c | 2 +- env/ext4.c | 2 +- env/fat.c | 2 +- env/flash.c | 2 +- env/mmc.c | 4 ++-- env/nand.c | 4 ++-- env/nvram.c | 2 +- env/onenand.c | 2 +- env/remote.c | 2 +- env/sata.c | 2 +- env/sf.c | 4 ++-- env/ubi.c | 4 ++-- include/env.h | 7 +++++-- include/search.h | 1 + 15 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/env/common.c b/env/common.c index 0db56e610a..ed18378000 100644 --- a/env/common.c +++ b/env/common.c @@ -110,7 +110,7 @@ int env_set_default_vars(int nvars, char * const vars[], int flags) * Check if CRC is valid and (if yes) import the environment. * Note that "buf" may or may not be aligned. */ -int env_import(const char *buf, int check) +int env_import(const char *buf, int check, int flags) { env_t *ep = (env_t *)buf;

@@ -125,7 +125,7 @@ int env_import(const char *buf, int check) } }

- if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0, + if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', flags, 0, 0, NULL)) { gd->flags |= GD_FLG_ENV_READY; return 0; @@ -142,7 +142,8 @@ int env_import(const char *buf, int check) static unsigned char env_flags;

int env_import_redund(const char *buf1, int buf1_read_fail, - const char *buf2, int buf2_read_fail) + const char *buf2, int buf2_read_fail, + int flags) { int crc1_ok, crc2_ok; env_t *ep, *tmp_env1, *tmp_env2; @@ -162,10 +163,10 @@ int env_import_redund(const char *buf1, int buf1_read_fail, return -EIO; } else if (!buf1_read_fail && buf2_read_fail) { gd->env_valid = ENV_VALID; - return env_import((char *)tmp_env1, 1); + return env_import((char *)tmp_env1, 1, flags); } else if (buf1_read_fail && !buf2_read_fail) { gd->env_valid = ENV_REDUND; - return env_import((char *)tmp_env2, 1); + return env_import((char *)tmp_env2, 1, flags); }

crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) == @@ -200,7 +201,7 @@ int env_import_redund(const char *buf1, int buf1_read_fail, ep = tmp_env2;

env_flags = ep->flags; - return env_import((char *)ep, 0); + return env_import((char *)ep, 0, flags); } #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */

diff --git a/env/eeprom.c b/env/eeprom.c index e8126cfe39..e300470ad0 100644 --- a/env/eeprom.c +++ b/env/eeprom.c @@ -188,7 +188,7 @@ static int env_eeprom_load(void) eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off, (uchar *)buf_env, CONFIG_ENV_SIZE);

- return env_import(buf_env, 1); + return env_import(buf_env, 1, H_EXTERNAL); }

static int env_eeprom_save(void) diff --git a/env/ext4.c b/env/ext4.c index 8e90bb71b7..b6d38324d1 100644 --- a/env/ext4.c +++ b/env/ext4.c @@ -124,7 +124,7 @@ static int env_ext4_load(void) goto err_env_relocate; }

- return env_import(buf, 1); + return env_import(buf, 1, H_EXTERNAL);

err_env_relocate: env_set_default(NULL, 0); diff --git a/env/fat.c b/env/fat.c index 35a1955e63..9f66a6d642 100644 --- a/env/fat.c +++ b/env/fat.c @@ -116,7 +116,7 @@ static int env_fat_load(void) goto err_env_relocate; }

- return env_import(buf, 1); + return env_import(buf, 1, H_EXTERNAL);

err_env_relocate: env_set_default(NULL, 0); diff --git a/env/flash.c b/env/flash.c index 3198147c38..722d5adf8b 100644 --- a/env/flash.c +++ b/env/flash.c @@ -351,7 +351,7 @@ static int env_flash_load(void) "reading environment; recovered successfully\n\n"); #endif /* CONFIG_ENV_ADDR_REDUND */

- return env_import((char *)flash_addr, 1); + return env_import((char *)flash_addr, 1, H_EXTERNAL); } #endif /* LOADENV */

diff --git a/env/mmc.c b/env/mmc.c index a8b661db80..d8fb51ffe6 100644 --- a/env/mmc.c +++ b/env/mmc.c @@ -332,7 +332,7 @@ static int env_mmc_load(void) read2_fail = read_env(mmc, CONFIG_ENV_SIZE, offset2, tmp_env2);

ret = env_import_redund((char *)tmp_env1, read1_fail, (char *)tmp_env2, - read2_fail); + read2_fail, H_EXTERNAL);

fini: fini_mmc_for_env(mmc); @@ -374,7 +374,7 @@ static int env_mmc_load(void) goto fini; }

- ret = env_import(buf, 1); + ret = env_import(buf, 1, H_EXTERNAL); if (!ret) { ep = (env_t *)buf; gd->env_addr = (ulong)&ep->data; diff --git a/env/nand.c b/env/nand.c index 8b0027d304..0d7ee19bc2 100644 --- a/env/nand.c +++ b/env/nand.c @@ -331,7 +331,7 @@ static int env_nand_load(void) read2_fail = readenv(CONFIG_ENV_OFFSET_REDUND, (u_char *) tmp_env2);

ret = env_import_redund((char *)tmp_env1, read1_fail, (char *)tmp_env2, - read2_fail); + read2_fail, H_EXTERNAL);

done: free(tmp_env1); @@ -372,7 +372,7 @@ static int env_nand_load(void) return -EIO; }

- return env_import(buf, 1); + return env_import(buf, 1, H_EXTERNAL); #endif /* ! ENV_IS_EMBEDDED */

return 0; diff --git a/env/nvram.c b/env/nvram.c index 1a9fcf1c06..7c8ea26f96 100644 --- a/env/nvram.c +++ b/env/nvram.c @@ -64,7 +64,7 @@ static int env_nvram_load(void) #else memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE); #endif - return env_import(buf, 1); + return env_import(buf, 1, H_EXTERNAL); }

static int env_nvram_save(void) diff --git a/env/onenand.c b/env/onenand.c index dfd4e939f8..a2477cef9b 100644 --- a/env/onenand.c +++ b/env/onenand.c @@ -55,7 +55,7 @@ static int env_onenand_load(void) mtd->writesize = MAX_ONENAND_PAGESIZE; #endif /* !ENV_IS_EMBEDDED */

- rc = env_import(buf, 1); + rc = env_import(buf, 1, H_EXTERNAL); if (!rc) gd->env_valid = ENV_VALID;

diff --git a/env/remote.c b/env/remote.c index e3f0608b16..d93a137376 100644 --- a/env/remote.c +++ b/env/remote.c @@ -45,7 +45,7 @@ static int env_remote_save(void) static int env_remote_load(void) { #ifndef ENV_IS_EMBEDDED - return env_import((char *)env_ptr, 1); + return env_import((char *)env_ptr, 1, H_EXTERNAL); #endif

return 0; diff --git a/env/sata.c b/env/sata.c index 8bfcc94306..9442cfcaf3 100644 --- a/env/sata.c +++ b/env/sata.c @@ -111,7 +111,7 @@ static void env_sata_load(void) return -EIO; }

- return env_import(buf, 1); + return env_import(buf, 1, H_EXTERNAL); }

U_BOOT_ENV_LOCATION(sata) = { diff --git a/env/sf.c b/env/sf.c index 3e524f2947..81d6e74127 100644 --- a/env/sf.c +++ b/env/sf.c @@ -172,7 +172,7 @@ static int env_sf_load(void) CONFIG_ENV_SIZE, tmp_env2);

ret = env_import_redund((char *)tmp_env1, read1_fail, (char *)tmp_env2, - read2_fail); + read2_fail, H_EXTERNAL);

spi_flash_free(env_flash); env_flash = NULL; @@ -265,7 +265,7 @@ static int env_sf_load(void) goto err_read; }

- ret = env_import(buf, 1); + ret = env_import(buf, 1, H_EXTERNAL); if (!ret) gd->env_valid = ENV_VALID;

diff --git a/env/ubi.c b/env/ubi.c index 08aac47df2..5502efe28b 100644 --- a/env/ubi.c +++ b/env/ubi.c @@ -141,7 +141,7 @@ static int env_ubi_load(void) CONFIG_ENV_UBI_PART, CONFIG_ENV_UBI_VOLUME_REDUND);

return env_import_redund((char *)tmp_env1, read1_fail, (char *)tmp_env2, - read2_fail); + read2_fail, H_EXTERNAL); } #else /* ! CONFIG_SYS_REDUNDAND_ENVIRONMENT */ static int env_ubi_load(void) @@ -172,7 +172,7 @@ static int env_ubi_load(void) return -EIO; }

- return env_import(buf, 1); + return env_import(buf, 1, H_EXTERNAL); } #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */

diff --git a/include/env.h b/include/env.h index d6c2d751d6..8cc70fd752 100644 --- a/include/env.h +++ b/include/env.h @@ -288,10 +288,11 @@ int env_erase(void); * @buf: Buffer containing the environment (struct environemnt_s *) * @check: non-zero to check the CRC at the start of the environment, 0 to * ignore it + * @flags: Flags controlling matching (H_... - see search.h) * @return 0 if imported successfully, -ENOMSG if the CRC was bad, -EIO if * something else went wrong */ -int env_import(const char *buf, int check); +int env_import(const char *buf, int check, int flags);

/** * env_export() - Export the environment to a buffer @@ -310,10 +311,12 @@ int env_export(struct environment_s *env_out); * @buf1_read_fail: 0 if buf1 is valid, non-zero if invalid * @buf2: Second environment (struct environemnt_s *) * @buf2_read_fail: 0 if buf2 is valid, non-zero if invalid + * @flags: Flags controlling matching (H_... - see search.h) * @return 0 if OK, -EIO if no environment is valid, -ENOMSG if the CRC was bad */ int env_import_redund(const char *buf1, int buf1_read_fail, - const char *buf2, int buf2_read_fail); + const char *buf2, int buf2_read_fail, + int flags);

/** * env_get_default() - Look up a variable from the default environment diff --git a/include/search.h b/include/search.h index c4b50c9630..e56843c26f 100644 --- a/include/search.h +++ b/include/search.h @@ -113,5 +113,6 @@ int hwalk_r(struct hsearch_data *htab, #define H_PROGRAMMATIC (1 << 9) /* indicate that an import is from env_set() */ #define H_ORIGIN_FLAGS (H_INTERACTIVE | H_PROGRAMMATIC) #define H_DEFAULT (1 << 10) /* indicate that an import is default env */ +#define H_EXTERNAL (1 << 11) /* indicate that an import is external env */

#endif /* _SEARCH_H_ */

Add .load callback for the 'nowhere' environment driver. This is useful for when the 'nowhere' driver is used in combination with other drivers and should be used to load the default environment.

Signed-off-by: Marek Vasut marex@denx.de --- V2: No change --- env/nowhere.c | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/env/nowhere.c b/env/nowhere.c index f5b0a17652..417a636f83 100644 --- a/env/nowhere.c +++ b/env/nowhere.c @@ -15,6 +15,12 @@

DECLARE_GLOBAL_DATA_PTR;

+static int env_nowhere_load(void) +{ + env_set_default(NULL, 0); + + return 0; +} /* * Because we only ever have the default environment available we must mark * it as invalid. @@ -30,5 +36,6 @@ static int env_nowhere_init(void) U_BOOT_ENV_LOCATION(nowhere) = { .location = ENVL_NOWHERE, .init = env_nowhere_init, + .load = env_nowhere_load, ENV_NAME("nowhere") };

This option marks any U-Boot variable which does not have explicit 'w' writeable flag set as read-only. This way the environment can be locked down and only variables explicitly configured to be writeable can ever be changed by either 'env import', 'env set' or loading user environment from environment storage.

Signed-off-by: Marek Vasut marex@denx.de --- V2: - Only apply the filtering on external env, U-Boot can set variables from U-Boot shell and so on. - Switch from if CONFIG_IS_ENABLED(ENV_WRITEABLE_LIST) to ifdef CONFIG_ENV_WRITEABLE_LIST --- env/Kconfig | 8 ++++++ env/flags.c | 62 +++++++++++++++++++++++++++++++++++++-------- include/env_flags.h | 6 ++++- lib/hashtable.c | 5 +++- 4 files changed, 68 insertions(+), 13 deletions(-)

diff --git a/env/Kconfig b/env/Kconfig index 9f7eff4f69..44698d863d 100644 --- a/env/Kconfig +++ b/env/Kconfig @@ -613,6 +613,14 @@ config ENV_APPEND with newly imported data. This may be used in combination with static flags to e.g. to protect variables which must not be modified.

+config ENV_WRITEABLE_LIST + bool "Permit write access only to listed variables" + default n + help + If defined, only environment variables which explicitly set the 'w' + writeable flag can be written and modified at runtime. No variables + can be otherwise created, written or imported into the environment. + config ENV_ACCESS_IGNORE_FORCE bool "Block forced environment operations" default n diff --git a/env/flags.c b/env/flags.c index f7a53775c4..df4aed26b2 100644 --- a/env/flags.c +++ b/env/flags.c @@ -28,8 +28,15 @@ #define ENV_FLAGS_NET_VARTYPE_REPS "" #endif

+#ifdef CONFIG_ENV_WRITEABLE_LIST +#define ENV_FLAGS_WRITEABLE_VARACCESS_REPS "w" +#else +#define ENV_FLAGS_WRITEABLE_VARACCESS_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 char env_flags_varaccess_rep[] = + "aroc" ENV_FLAGS_WRITEABLE_VARACCESS_REPS; static const int env_flags_varaccess_mask[] = { 0, ENV_FLAGS_VARACCESS_PREVENT_DELETE | @@ -38,7 +45,11 @@ static const int env_flags_varaccess_mask[] = { ENV_FLAGS_VARACCESS_PREVENT_DELETE | ENV_FLAGS_VARACCESS_PREVENT_OVERWR, ENV_FLAGS_VARACCESS_PREVENT_DELETE | - ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR}; + ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR, +#ifdef CONFIG_ENV_WRITEABLE_LIST + ENV_FLAGS_VARACCESS_WRITEABLE, +#endif + };

#ifdef CONFIG_CMD_ENV_FLAGS static const char * const env_flags_vartype_names[] = { @@ -56,6 +67,9 @@ static const char * const env_flags_varaccess_names[] = { "read-only", "write-once", "change-default", +#ifdef CONFIG_ENV_WRITEABLE_LIST + "writeable", +#endif };

/* @@ -130,21 +144,25 @@ enum env_flags_vartype env_flags_parse_vartype(const char *flags) */ enum env_flags_varaccess env_flags_parse_varaccess(const char *flags) { + enum env_flags_varaccess va_default = env_flags_varaccess_any; + enum env_flags_varaccess va; char *access;

if (strlen(flags) <= ENV_FLAGS_VARACCESS_LOC) - return env_flags_varaccess_any; + return va_default;

access = strchr(env_flags_varaccess_rep, flags[ENV_FLAGS_VARACCESS_LOC]);

- if (access != NULL) - return (enum env_flags_varaccess) + if (access != NULL) { + va = (enum env_flags_varaccess) (access - &env_flags_varaccess_rep[0]); + return va; + }

printf("## Warning: Unknown environment variable access method '%c'\n", flags[ENV_FLAGS_VARACCESS_LOC]); - return env_flags_varaccess_any; + return va_default; }

/* @@ -152,17 +170,21 @@ enum env_flags_varaccess env_flags_parse_varaccess(const char *flags) */ enum env_flags_varaccess env_flags_parse_varaccess_from_binflags(int binflags) { + enum env_flags_varaccess va_default = env_flags_varaccess_any; + enum env_flags_varaccess va; int i;

for (i = 0; i < ARRAY_SIZE(env_flags_varaccess_mask); i++) if (env_flags_varaccess_mask[i] == - (binflags & ENV_FLAGS_VARACCESS_BIN_MASK)) - return (enum env_flags_varaccess)i; + (binflags & ENV_FLAGS_VARACCESS_BIN_MASK)) { + va = (enum env_flags_varaccess)i; + return va; + }

printf("Warning: Non-standard access flags. (0x%x)\n", binflags & ENV_FLAGS_VARACCESS_BIN_MASK);

- return env_flags_varaccess_any; + return va_default; }

static inline int is_hex_prefix(const char *value) @@ -326,13 +348,14 @@ enum env_flags_vartype env_flags_get_type(const char *name) enum env_flags_varaccess env_flags_get_varaccess(const char *name) { const char *flags_list = env_get(ENV_FLAGS_VAR); + enum env_flags_varaccess va_default = env_flags_varaccess_any; char flags[ENV_FLAGS_ATTR_MAX_LEN + 1];

if (env_flags_lookup(flags_list, name, flags)) - return env_flags_varaccess_any; + return va_default;

if (strlen(flags) <= ENV_FLAGS_VARACCESS_LOC) - return env_flags_varaccess_any; + return va_default;

return env_flags_parse_varaccess(flags); } @@ -426,7 +449,11 @@ void env_flags_init(struct env_entry *var_entry) int ret = 1;

if (first_call) { +#ifdef CONFIG_ENV_WRITEABLE_LIST + flags_list = ENV_FLAGS_LIST_STATIC; +#else flags_list = env_get(ENV_FLAGS_VAR); +#endif first_call = 0; } /* look in the ".flags" and static for a reference to this variable */ @@ -523,6 +550,19 @@ int env_flags_validate(const struct env_entry *item, const char *newval, }

/* check for access permission */ +#ifdef CONFIG_ENV_WRITEABLE_LIST + if (flag & H_DEFAULT) + return 0; /* Default env is always OK */ + + /* + * External writeable variables can be overwritten by external env, + * anything else can not be overwritten by external env. + */ + if ((flag & H_EXTERNAL) && + !(item->flags & ENV_FLAGS_VARACCESS_WRITEABLE)) + return 1; +#endif + #ifndef CONFIG_ENV_ACCESS_IGNORE_FORCE if (flag & H_FORCE) { printf("## Error: Can't force access to "%s"\n", name); diff --git a/include/env_flags.h b/include/env_flags.h index 725841a891..313cb8c49a 100644 --- a/include/env_flags.h +++ b/include/env_flags.h @@ -24,6 +24,9 @@ enum env_flags_varaccess { env_flags_varaccess_readonly, env_flags_varaccess_writeonce, env_flags_varaccess_changedefault, +#ifdef CONFIG_ENV_WRITEABLE_LIST + env_flags_varaccess_writeable, +#endif env_flags_varaccess_end };

@@ -173,6 +176,7 @@ int env_flags_validate(const struct env_entry *item, const char *newval, #define ENV_FLAGS_VARACCESS_PREVENT_CREATE 0x00000010 #define ENV_FLAGS_VARACCESS_PREVENT_OVERWR 0x00000020 #define ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR 0x00000040 -#define ENV_FLAGS_VARACCESS_BIN_MASK 0x00000078 +#define ENV_FLAGS_VARACCESS_WRITEABLE 0x00000080 +#define ENV_FLAGS_VARACCESS_BIN_MASK 0x000000f8

#endif /* __ENV_FLAGS_H__ */ diff --git a/lib/hashtable.c b/lib/hashtable.c index ef834badc5..4a8c50b4b8 100644 --- a/lib/hashtable.c +++ b/lib/hashtable.c @@ -950,9 +950,12 @@ int himport_r(struct hsearch_data *htab, e.data = value;

hsearch_r(e, ENV_ENTER, &rv, htab, flag); - if (rv == NULL) +#if !CONFIG_IS_ENABLED(ENV_WRITEABLE_LIST) + if (rv == NULL) { printf("himport_r: can't insert "%s=%s" into hash table\n", name, value); + } +#endif

debug("INSERT: table %p, filled %d/%d rv %p ==> name="%s" value="%s"\n", htab, htab->filled, htab->size,

On Tue, Jul 7, 2020 at 7:52 PM Marek Vasut marex@denx.de wrote:

If the ENV_ACCESS_IGNORE_FORCE is set, inform user that the variable cannot be force-set if such attempt happens.

Signed-off-by: Marek Vasut marex@denx.de

V2: No change

env/flags.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/env/flags.c b/env/flags.c index b88fe7ba9c..f7a53775c4 100644 --- a/env/flags.c +++ b/env/flags.c @@ -524,8 +524,10 @@ int env_flags_validate(const struct env_entry *item, const char *newval,

    /* check for access permission */

#ifndef CONFIG_ENV_ACCESS_IGNORE_FORCE

•   if (flag & H_FORCE)
  

•   if (flag & H_FORCE) {
  

•           printf("## Error: Can't force access to \"%s\"\n", name);
            return 0;
  

•   }
  

#endif switch (op) { case env_op_delete:

AFAICT this is wrong - you get the message when you have CONFIG_ENV_ACCESS_IGNORE_FORCE disabled and use force:

=> env print ethaddr ethaddr=00:1C:2B:08:AF:65 => env set ethaddr 00:00:00:00:00:00 ## Error: Can't overwrite "ethaddr" ## Error inserting "ethaddr" variable, errno=1 => env print ethaddr ethaddr=00:1C:2B:08:AF:65 => env set -f ethaddr 00:00:00:00:00:00 ## Error: Can't force access to "ethaddr" => env print ethaddr ethaddr=00:00:00:00:00:00

Just staring at the code, I don't see a good way to capture this behaviour, other than wiring it into each of the branches of the switch - I started off with something like this:

diff --git a/env/flags.c b/env/flags.c index df4aed26b2c6..70621dff4434 100644 --- a/env/flags.c +++ b/env/flags.c @@ -563,12 +563,13 @@ int env_flags_validate(const struct env_entry *item, const char *newval, return 1; #endif

-#ifndef CONFIG_ENV_ACCESS_IGNORE_FORCE if (flag & H_FORCE) { - printf("## Error: Can't force access to "%s"\n", name); - return 0; + if (CONFIG_IS_ENABLED(ENV_ACCESS_IGNORE_FORCE)) + printf("## Error: Can't force access to "%s"\n", name); + else + return 0; } -#endif + switch (op) { case env_op_delete: if (item->flags & ENV_FLAGS_VARACCESS_PREVENT_DELETE) {

But I think with that you'll get the message for variables which can be overwritten, so still not what's intended.

-- Alex Kiernan