From 656703759d7d3eac6e8c86f1121cde7dfd6d8cbd Mon Sep 17 00:00:00 2001 From: "ananth@in.ibm.com" Date: Fri, 12 Mar 2004 00:57:36 -0800 Subject: [PATCH] more Libsysfs updates On Thu, Mar 11, 2004 at 02:36:23PM +0100, Kay Sievers wrote: > On Thu, 2004-03-11 at 15:02, Ananth N Mavinakayanahalli wrote: > > On Thu, Mar 11, 2004 at 02:04:36PM +0100, Kay Sievers wrote: > > > On Thu, Mar 11, 2004 at 11:53:50AM +0500, Ananth N Mavinakayanahalli wrote: > > > > > > > +#define safestrcpy(to, from) strncpy(to, from, sizeof(to)-1) > > > > +#define safestrcat(to, from) strncat(to, from, sizeof(to) - strlen(to)-1) > > > > > > These strings are not terminated with '\0' if from is longer than > > > the sizeof to. > > > > Did not do it on purpose as the "to" elements are either calloc'd or memset to > > '0' explicitly in the library. Thats the reason I mentioned "scaled down" :) > > Ahh, sounds good. > > > > > +#define safestrncpy(to, from, maxsize) \ > > > > +do { \ > > > > + to[maxsize-1] = '\0'; \ > > > > + strncpy(to, from, maxsize-1); \ > > > > +} while (0) > > > > + > > > > +#define safestrncat(to, from, maxsize) \ > > > > +do { \ > > > > + to[maxsize-1] = '\0'; \ > > > > + strncat(to, from, maxsize - strlen(to)-1); \ > > > > +} while (0) > > > > > > We all expect a similar behavior like strncat/strncpy according to the > > > names, but these macros are limiting by the target size and do not limit > > > the count of chars copied. > > > This is confusing I think and suggest using a different name like > > > 'safestrcopymax()' or something. > > > > Good point.. will make the change > > Nice. I've had these *n* names too and I forgot about the logic and only > 10 days later I introduced a ugly bug cause I can't limit the count of > copied chars :) Inlined is the patch for this... applies on the earlier _BIG_ patch. --- libsysfs/sysfs_utils.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'libsysfs/sysfs_utils.c') diff --git a/libsysfs/sysfs_utils.c b/libsysfs/sysfs_utils.c index 699a9829b8..492c7fa668 100644 --- a/libsysfs/sysfs_utils.c +++ b/libsysfs/sysfs_utils.c @@ -67,7 +67,7 @@ static int sysfs_get_fs_mnt_path(const char *fs_type, char *mnt_path, size_t len) { #ifdef __KLIBC__ - safestrncpy(mnt_path, "/sys", len); + safestrcpymax(mnt_path, "/sys", len); return 0; #else FILE *mnt; @@ -89,7 +89,7 @@ static int sysfs_get_fs_mnt_path(const char *fs_type, if (strcmp(mntent->mnt_type, fs_type) == 0) { dirlen = strlen(mntent->mnt_dir); if (dirlen <= (len - 1)) { - safestrncpy(mnt_path, mntent->mnt_dir, len); + safestrcpymax(mnt_path, mntent->mnt_dir, len); } else { dprintf("Error - mount path too long\n"); ret = -1; @@ -126,7 +126,7 @@ int sysfs_get_mnt_path(char *mnt_path, size_t len) } sysfs_path = getenv(SYSFS_PATH_ENV); if (sysfs_path != NULL) { - safestrncpy(mnt_path, sysfs_path, len); + safestrcpymax(mnt_path, sysfs_path, len); if ((sysfs_remove_trailing_slash(mnt_path)) != 0) return 1; } else @@ -166,7 +166,7 @@ int sysfs_get_name_from_path(const char *path, char *name, size_t len) } } n++; - safestrncpy(name, n, len); + safestrcpymax(name, n, len); return 0; } @@ -221,7 +221,7 @@ int sysfs_get_link(const char *path, char *target, size_t len) } else { safestrcpy(temp_path, d); } - safestrncpy(target, temp_path, len); + safestrcpymax(target, temp_path, len); break; /* * relative path @@ -240,12 +240,12 @@ parse_path: if (*s == '/') count++; } - safestrncpy(s, d, (SYSFS_PATH_MAX-strlen(devdir))); - safestrncpy(target, devdir, len); + safestrcpymax(s, d, (SYSFS_PATH_MAX-strlen(devdir))); + safestrcpymax(target, devdir, len); break; case '/': /* absolute path - copy as is */ - safestrncpy(target, linkpath, len); + safestrcpymax(target, linkpath, len); break; default: /* relative path from this directory */ @@ -257,7 +257,7 @@ parse_path: } else { safestrcpy(temp_path, linkpath); } - safestrncpy(target, temp_path, len); + safestrcpymax(target, temp_path, len); } return 0; } @@ -330,7 +330,7 @@ struct dlist *sysfs_open_subsystem_list(char *name) dlist_for_each_data(dir->subdirs, cur, struct sysfs_directory) { subsys_name = (char *)calloc(1, SYSFS_NAME_LEN); - safestrncpy(subsys_name, cur->name, SYSFS_NAME_LEN); + safestrcpymax(subsys_name, cur->name, SYSFS_NAME_LEN); dlist_unshift_sorted(list, subsys_name, sort_char); } } @@ -345,11 +345,11 @@ struct dlist *sysfs_open_subsystem_list(char *name) if (c == NULL) goto out; *c = '\0'; - safestrncpy(c, SYSFS_BLOCK_NAME, + safestrcpymax(c, SYSFS_BLOCK_NAME, sizeof(sysfs_path) - strlen(sysfs_path)); if ((sysfs_path_is_dir(sysfs_path)) == 0) { subsys_name = (char *)calloc(1, SYSFS_NAME_LEN); - safestrncpy(subsys_name, SYSFS_BLOCK_NAME, + safestrcpymax(subsys_name, SYSFS_BLOCK_NAME, SYSFS_NAME_LEN); dlist_unshift_sorted(list, subsys_name, sort_char); } @@ -409,7 +409,7 @@ struct dlist *sysfs_open_bus_devices_list(char *name) dlist_for_each_data(dir->links, cur, struct sysfs_link) { device_name = (char *)calloc(1, SYSFS_NAME_LEN); - safestrncpy(device_name, cur->name, SYSFS_NAME_LEN); + safestrcpymax(device_name, cur->name, SYSFS_NAME_LEN); dlist_unshift_sorted(list, device_name, sort_char); } } -- cgit v1.2.3-54-g00ecf