[U-Boot,v0,1/4] Groundwork for generalization of env interface

Message ID	1319647072-17504-2-git-send-email-gerlando.falauto@keymile.com
State	Changes Requested
Headers	show Return-Path: <u-boot-bounces@lists.denx.de> From: Gerlando Falauto <gerlando.falauto@keymile.com> To: u-boot@lists.denx.de Date: Wed, 26 Oct 2011 18:37:49 +0200 Message-Id: <1319647072-17504-2-git-send-email-gerlando.falauto@keymile.com> In-Reply-To: <1319647072-17504-1-git-send-email-gerlando.falauto@keymile.com> References: <1319647072-17504-1-git-send-email-gerlando.falauto@keymile.com> Cc: holger.brunck@keymile.com, Gerlando Falauto <gerlando.falauto@keymile.com> Subject: [U-Boot] [PATCH v0 1/4] Groundwork for generalization of env interface Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: u-boot-bounces@lists.denx.de Errors-To: u-boot-bounces@lists.denx.de

diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c index fa99c44..10b9552 100644 --- a/common/cmd_nvedit.c +++ b/common/cmd_nvedit.c @@ -194,32 +194,23 @@ static int do_env_grep (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[ #endif /* - * Set a new environment variable, - * or replace or delete an existing one. + * Performs consistency checking before setting, replacing, + * or deleting an environment variable, then (if successful) + * apply the changes to internals so to make them effective. + * Code for this function was taken out of _do_env_set(), + * which now calls it. + * Also called as a callback function by himport_ex(). + * Returns 0 in case of success, 1 in case of failure. + * When (flag & H_FORCE) is set, force overwriting of + * write-once variables. */ -int _do_env_set (int flag, int argc, char * const argv[]) +int env_check_apply(const char *name, const char *oldval, + const char *newval, int flag) { bd_t *bd = gd->bd; - int i, len; + int i; int console = -1; - char *name, *value, *s; - ENTRY e, *ep; - - name = argv[1]; - - if (strchr(name, '=')) { - printf("## Error: illegal character '=' in variable name \"%s\"\n", name); - return 1; - } - - env_id++; - /* - * search if variable with this name already exists - */ - e.key = name; - e.data = NULL; - hsearch_r(e, FIND, &ep, &env_htab); /* Check for console redirection */ if (strcmp(name, "stdin") == 0) @@ -230,22 +221,23 @@ int _do_env_set (int flag, int argc, char * const argv[]) console = stderr; if (console != -1) { - if (argc < 3) { /* Cannot delete it! */ + if ((newval == NULL) || (*newval == '\0')) { + /* We cannot delete stdin/stdout/stderr */ printf("Can't delete \"%s\"\n", name); return 1; } #ifdef CONFIG_CONSOLE_MUX - i = iomux_doenv(console, argv[2]); + i = iomux_doenv(console, newval); if (i) return i; #else /* Try assigning specified device */ - if (console_assign(console, argv[2]) < 0) + if (console_assign(console, newval) < 0) return 1; #ifdef CONFIG_SERIAL_MULTI - if (serial_assign(argv[2]) < 0) + if (serial_assign(newval) < 0) return 1; #endif #endif /* CONFIG_CONSOLE_MUX */ @@ -255,23 +247,29 @@ int _do_env_set (int flag, int argc, char * const argv[]) * Some variables like "ethaddr" and "serial#" can be set only * once and cannot be deleted; also, "ver" is readonly. */ - if (ep) { /* variable exists */ + if ((oldval != NULL) /* variable exists */ + && ((flag & H_FORCE) == 0)) { /* and we are not forced */ #ifndef CONFIG_ENV_OVERWRITE if ((strcmp(name, "serial#") == 0) || ((strcmp(name, "ethaddr") == 0) #if defined(CONFIG_OVERWRITE_ETHADDR_ONCE) && defined(CONFIG_ETHADDR) - && (strcmp(ep->data, MK_STR(CONFIG_ETHADDR)) != 0) + && (strcmp(oldval, MK_STR(CONFIG_ETHADDR)) != 0) #endif /* CONFIG_OVERWRITE_ETHADDR_ONCE && CONFIG_ETHADDR */ ) ) { printf("Can't overwrite \"%s\"\n", name); return 1; } #endif + } + /* if variable exists... */ + if ((oldval != NULL) + /* or we are in a scratched-out environment */ + || ((flag & H_NOCLEAR) == 0)) { /* * Switch to new baudrate if new baudrate is supported */ if (strcmp(name, "baudrate") == 0) { - int baudrate = simple_strtoul(argv[2], NULL, 10); + int baudrate = simple_strtoul(newval, NULL, 10); int i; for (i = 0; i < N_BAUDRATES; ++i) { if (baudrate == baudrate_table[i]) @@ -282,6 +280,10 @@ int _do_env_set (int flag, int argc, char * const argv[]) baudrate); return 1; } + if (gd->baudrate == baudrate) { + /* If unchanged, we just say it's OK */ + return 0; + } printf ("## Switch baudrate to %d bps and press ENTER ...\n", baudrate); udelay(50000); @@ -299,6 +301,72 @@ int _do_env_set (int flag, int argc, char * const argv[]) } } + /* + * Some variables should be updated when the corresponding + * entry in the environment is changed + */ + + if (strcmp(name, "ipaddr") == 0) { + const char *s = newval; /* always use only one arg */ + char *e; + unsigned long addr; + bd->bi_ip_addr = 0; + for (addr = 0, i = 0; i < 4; ++i) { + ulong val = s ? simple_strtoul(s, &e, 10) : 0; + addr <<= 8; + addr |= (val & 0xFF); + if (s) + s = (*e) ? e+1 : e; + } + bd->bi_ip_addr = htonl(addr); + return 0; + } else if (strcmp(newval, "loadaddr") == 0) { + load_addr = simple_strtoul(newval, NULL, 16); + return 0; + } +#if defined(CONFIG_CMD_NET) + else if (strcmp(newval, "bootfile") == 0) { + copy_filename(BootFile, newval, sizeof(BootFile)); + return 0; + } +#endif + return 0; +} + +/* + * Set a new environment variable, + * or replace or delete an existing one. +*/ +int _do_env_set(int flag, int argc, char * const argv[]) +{ + int i, len; + char *name, *value, *s; + ENTRY e, *ep; + + name = argv[1]; + value = argv[2]; + + if (strchr(name, '=')) { + printf("## Error: illegal character '='" + "in variable name \"%s\"\n", name); + return 1; + } + + env_id++; + /* + * search if variable with this name already exists + */ + e.key = name; + e.data = NULL; + hsearch_r(e, FIND, &ep, &env_htab); + + /* Perform requested checks. Notice how since we are overwriting + * a single variable, we need to set H_NOCLEAR */ + if (env_check_apply(name, ep ? ep->data : NULL, value, H_NOCLEAR)) { + debug("check function did not approve, refusing\n"); + return 1; + } + /* Delete only ? */ if ((argc < 3) || argv[2] == NULL) { int rc = hdelete_r(name, &env_htab); @@ -336,34 +404,6 @@ int _do_env_set (int flag, int argc, char * const argv[]) return 1; } - /* - * Some variables should be updated when the corresponding - * entry in the environment is changed - */ - - if (strcmp(name, "ipaddr") == 0) { - char *s = argv[2]; /* always use only one arg */ - char *e; - unsigned long addr; - bd->bi_ip_addr = 0; - for (addr = 0, i = 0; i < 4; ++i) { - ulong val = s ? simple_strtoul(s, &e, 10) : 0; - addr <<= 8; - addr |= (val & 0xFF); - if (s) s = (*e) ? e+1 : e; - } - bd->bi_ip_addr = htonl(addr); - return 0; - } else if (strcmp(argv[1], "loadaddr") == 0) { - load_addr = simple_strtoul(argv[2], NULL, 16); - return 0; - } -#if defined(CONFIG_CMD_NET) - else if (strcmp(argv[1], "bootfile") == 0) { - copy_filename(BootFile, argv[2], sizeof(BootFile)); - return 0; - } -#endif return 0; } diff --git a/common/env_common.c b/common/env_common.c index c7e9bea..db607e1 100644 --- a/common/env_common.c +++ b/common/env_common.c @@ -172,6 +172,9 @@ const uchar *env_get_addr (int index) void set_default_env(const char *s) { + /* By default, do not apply changes as they will eventually + * be applied by someone else */ + apply_cb apply_function = NULL; if (sizeof(default_environment) > ENV_SIZE) { puts("*** Error - default environment is too large\n\n"); return; @@ -183,14 +186,22 @@ void set_default_env(const char *s) "using default environment\n\n", s+1); } else { + /* This set_to_default was explicitly asked for + * by the user, as opposed to being a recovery + * mechanism. Therefore we chack every single + * variable and apply changes to the system + * right away (e.g. baudrate, console). + */ + apply_function = env_check_apply; puts(s); } } else { puts("Using default environment\n\n"); } - if (himport_r(&env_htab, (char *)default_environment, - sizeof(default_environment), '\0', 0) == 0) { + if (himport_ex(&env_htab, (char *)default_environment, + sizeof(default_environment), '\0', 0, + 0, NULL, apply_function) == 0) { error("Environment import failed: errno = %d\n", errno); } gd->flags |= GD_FLG_ENV_READY; diff --git a/include/environment.h b/include/environment.h index 6394a96..cd98f91 100644 --- a/include/environment.h +++ b/include/environment.h @@ -174,6 +174,13 @@ void set_default_env(const char *s); /* Import from binary representation into hash table */ int env_import(const char *buf, int check); +/* + * Check if variable "name" can be changed from oldval to newval, + * and if so, apply the changes (e.g. baudrate) + */ +int env_check_apply(const char *name, const char *oldval, + const char *newval, int flag); + #endif #endif /* _ENVIRONMENT_H_ */ diff --git a/include/search.h b/include/search.h index b4edd43..4ac7171 100644 --- a/include/search.h +++ b/include/search.h @@ -46,6 +46,11 @@ typedef struct entry { /* Opaque type for internal use. */ struct _ENTRY; +/* Callback function to be called for checking whether the given change may + * be applied or not. Must return 0 for approval, 1 for denial. */ +typedef int (*apply_cb)(const char *name, const char *oldval, + const char *newval, int flag); + /* * Family of hash table handling functions. The functions also * have reentrant counterparts ending with _r. The non-reentrant @@ -97,7 +102,15 @@ extern int himport_r(struct hsearch_data *__htab, const char *__env, size_t __size, const char __sep, int __flag); +extern int himport_ex(struct hsearch_data *__htab, + const char *__env, size_t __size, const char __sep, + int __flag, + int __argc, char * const __argv[], + apply_cb apply); + + /* Flags for himport_r() */ #define H_NOCLEAR 1 /* do not clear hash table before importing */ +#define H_FORCE 2 /* overwrite read-only/write-once variables */ #endif /* search.h */ diff --git a/lib/hashtable.c b/lib/hashtable.c index 6895550..a2c268f 100644 --- a/lib/hashtable.c +++ b/lib/hashtable.c @@ -630,6 +630,33 @@ ssize_t hexport_r(struct hsearch_data *htab, const char sep, int himport_r(struct hsearch_data *htab, const char *env, size_t size, const char sep, int flag) { + return himport_ex(htab, env, size, sep, flag, 0, NULL, NULL); +} + +/* Check whether variable name is amongst vars[] */ +static int process_var(const char *name, int nvars, char * const vars[]) +{ + int i = 0; + /* No variables specified means process all of them*/ + if (nvars == 0) + return 1; + + for (i = 0; i < nvars; i++) { + if (!strcmp(name, vars[i])) + return 1; + } + debug("Skipping non-listed variable %s\n", name); + return 0; +} + + + +int himport_ex(struct hsearch_data *htab, + const char *env, size_t size, const char sep, int flag, + int nvars, char * const vars[], + int(*apply)(const char *, const char *, const char *, int) + ) +{ char *data, *sp, *dp, *name, *value; /* Test for correct arguments. */ @@ -715,6 +742,8 @@ int himport_r(struct hsearch_data *htab, *dp++ = '\0'; /* terminate name */ debug("DELETE CANDIDATE: \"%s\"\n", name); + if (!process_var(name, nvars, vars)) + continue; if (hdelete_r(name, htab) == 0) debug("DELETE ERROR ##############################\n"); @@ -732,10 +761,31 @@ int himport_r(struct hsearch_data *htab, *sp++ = '\0'; /* terminate value */ ++dp; + /* Skip variables which are not supposed to be treated */ + if (!process_var(name, nvars, vars)) + continue; + /* enter into hash table */ e.key = name; e.data = value; + /* if there is an apply function, check what it has to say */ + if (apply != NULL) { + debug("searching before calling cb function" + " for %s\n", name); + /* + * Search for variable in existing env, so to pass + * its previous value to the apply callback + */ + hsearch_r(e, FIND, &rv, htab); + debug("previous value was %s\n", rv ? rv->data : ""); + if (apply(name, rv ? rv->data : NULL, value, flag)) { + debug("callback function refused to set" + " variable %s, skipping it!\n", name); + continue; + } + } + hsearch_r(e, ENTER, &rv, htab); if (rv == NULL) { printf("himport_r: can't insert \"%s=%s\" into hash table\n",

[U-Boot,v0,1/4] Groundwork for generalization of env interface

Commit Message

Comments

Patch