From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Mon, 2 Apr 2012 22:51:36 +0200 Subject: [U-Boot] [PATCH v3 3/6] env: add check/apply logic to himport_r() In-Reply-To: <4F7A0FA5.1030301@keymile.com> References: <1321634955-5561-1-git-send-email-gerlando.falauto@keymile.com> <201204022101.38606.marex@denx.de> <4F7A0FA5.1030301@keymile.com> Message-ID: <201204022251.36802.marex@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Gerlando Falauto, > On 04/02/2012 09:01 PM, Marek Vasut wrote: > > Dear Marek Vasut, > > > >> Dear Gerlando Falauto, > >> > >>> Change hashtable so that a callback function will decide whether a > >>> variable can be overwritten, and possibly apply the changes. > >>> > >>> So add a new field to struct hsearch_data: > >>> o "apply" callback function to check whether a variable can be > >>> > >>> overwritten, and possibly immediately apply the changes; > >>> when NULL, no check is performed. > >>> > >>> And a new argument to himport_r(): > >>> o "do_apply": whether to call the apply callback function > >>> > >>> NOTE: This patch does not change the current behavior. > >>> > >>> Signed-off-by: Gerlando Falauto > >>> --- > >>> > >>> common/cmd_nvedit.c | 3 ++- > >>> common/env_common.c | 8 +++++--- > >>> include/environment.h | 9 +++++++++ > >>> include/search.h | 14 +++++++++++++- > >>> lib/hashtable.c | 20 +++++++++++++++++++- > >>> 5 files changed, 48 insertions(+), 6 deletions(-) > >>> > >>> diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c > >>> index 59668a6..fc6165f 100644 > >>> --- a/common/cmd_nvedit.c > >>> +++ b/common/cmd_nvedit.c > >>> @@ -201,6 +201,7 @@ static int do_env_grep(cmd_tbl_t *cmdtp, int flag, > >>> > >>> * 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 instead. > >>> + * Also called as a callback function by himport_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. > >>> @@ -931,7 +932,7 @@ static int do_env_import(cmd_tbl_t *cmdtp, int > >>> flag, > >>> > >>> } > >>> > >>> if (himport_r(&env_htab, addr, size, sep, del ? 0 : H_NOCLEAR, > >>> > >>> - 0, NULL) == 0) { > >>> + 0, NULL, 0 /* do_apply */) == 0) { > >>> > >>> error("Environment import failed: errno = %d\n", errno); > >>> return 1; > >>> > >>> } > >>> > >>> diff --git a/common/env_common.c b/common/env_common.c > >>> index a93c062..5558c1c 100644 > >>> --- a/common/env_common.c > >>> +++ b/common/env_common.c > >>> @@ -122,7 +122,9 @@ const uchar default_environment[] = { > >>> > >>> "\0" > >>> > >>> }; > >>> > >>> -struct hsearch_data env_htab; > >>> +struct hsearch_data env_htab = { > >>> + .apply = env_check_apply, > >>> +}; > >>> > >>> static uchar __env_get_char_spec(int index) > >>> { > >>> > >>> @@ -183,7 +185,7 @@ void set_default_env(const char *s) > >>> > >>> if (himport_r(&env_htab, (char *)default_environment, > >>> > >>> sizeof(default_environment), '\0', 0, > >>> > >>> - 0, NULL) == 0) > >>> + 0, NULL, 0 /* do_apply */) == 0) > >> > >> Please replace that 0 /*...*/ stuff with simple NULL > > > > Oh, it's integer ... so just remove the comment, sorry. > > The comment would have been a way to shed some light on one of the 8 > arguments the function takes. > But if it's against some coding style guideline, I'll simply remove it. Not really, I don't really care ;-) > > >>> error("Environment import failed: errno = %d\n", errno); > >>> > >>> gd->flags |= GD_FLG_ENV_READY; > >>> > >>> @@ -209,7 +211,7 @@ int env_import(const char *buf, int check) > >>> > >>> } > >>> > >>> if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, > >>> > >>> - 0, NULL)) { > >>> + 0, NULL, 0 /* do_apply */)) { > >> > >> DTTO, otherwise looks fine. > >> > >>> gd->flags |= GD_FLG_ENV_READY; > >>> return 1; > >>> > >>> } > >>> > >>> diff --git a/include/environment.h b/include/environment.h > >>> index 1ef44f3..236e179 100644 > >>> --- a/include/environment.h > >>> +++ b/include/environment.h > >>> @@ -193,6 +193,15 @@ 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). > >>> + * When (flag& H_FORCE) is set, it does not print out any error > >>> + * message and forces overwriting of write-once variables. > >>> + */ > >>> +int env_check_apply(const char *name, const char *oldval, > >>> + const char *newval, int flag); > >>> + > >>> > >>> #endif /* DO_DEPS_ONLY */ > >>> > >>> #endif /* _ENVIRONMENT_H_ */ > >>> > >>> diff --git a/include/search.h b/include/search.h > >>> index 94d75fc..721c8ac 100644 > >>> --- a/include/search.h > >>> +++ b/include/search.h > >>> @@ -57,6 +57,16 @@ struct hsearch_data { > >>> > >>> struct _ENTRY *table; > >>> unsigned int size; > >>> unsigned int filled; > >>> > >>> +/* > >>> + * Callback function which will check whether the given change for > >>> variable + * "name" from "oldval" to "newval" may be applied or not, > >>> and possibly apply + * such change. > >>> + * When (flag& H_FORCE) is set, it shall not print out any error > >>> message and + * shall force overwriting of write-once variables. > >>> +.* Must return 0 for approval, 1 for denial. > >>> + */ > >>> + int (*apply)(const char *name, const char *oldval, > >>> + const char *newval, int flag); > >>> > >>> }; > >>> > >>> /* Create a new hashing table which will at most contain NEL > >>> elements. */ > >>> > >>> @@ -97,10 +107,12 @@ extern ssize_t hexport_r(struct hsearch_data > >>> *__htab, > >>> > >>> /* > >>> > >>> * nvars: length of vars array > >>> * vars: array of strings (variable names) to import (nvars == 0 > >>> means > >>> > >>> all) + * do_apply: whether to call callback function to check the new > >>> argument, + * and possibly apply changes (false means accept > >>> everything) > >>> > >>> */ > >>> > >>> extern int himport_r(struct hsearch_data *__htab, > >>> > >>> const char *__env, size_t __size, const char __sep, > >>> > >>> - int __flag, int nvars, char * const vars[]); > >>> + int __flag, int nvars, char * const vars[], int do_apply); > >>> > >>> /* Flags for himport_r() */ > >>> #define H_NOCLEAR (1<< 0) /* do not clear hash table before > >> > >> importing */ > >> > >>> diff --git a/lib/hashtable.c b/lib/hashtable.c > >>> index 0610e86..6cfba56 100644 > >>> --- a/lib/hashtable.c > >>> +++ b/lib/hashtable.c > >>> @@ -658,7 +658,7 @@ static int is_var_in_set(const char *name, int > >>> nvars, char * const vars[]) > >>> > >>> int himport_r(struct hsearch_data *htab, > >>> > >>> const char *env, size_t size, const char sep, int flag, > >>> > >>> - int nvars, char * const vars[]) > >>> + int nvars, char * const vars[], int do_apply) > >>> > >>> { > >>> > >>> char *data, *sp, *dp, *name, *value; > >>> > >>> @@ -772,6 +772,24 @@ int himport_r(struct hsearch_data *htab, > >>> > >>> e.key = name; > >>> e.data = value; > >>> > >>> + /* if there is an apply function, check what it has to say */ > >>> + if (do_apply&& htab->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 (htab->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",