On Thu, Jul 15, 2021 at 12:52:22PM +0200, mwilck@xxxxxxxx wrote: > From: Martin Wilck <mwilck@xxxxxxxx> > > We can avoid some buffer length checks here, too. Also, simplify the > implementation of format_devname(). > > Created a wrapper for the format_devname() test case, to avoid chaning > the test cases themselves. > > Signed-off-by: Martin Wilck <mwilck@xxxxxxxx> Reviewed-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx> > --- > libmultipath/alias.c | 84 +++++++++++++++++++------------------------- > tests/alias.c | 41 +++++++++++++-------- > 2 files changed, 63 insertions(+), 62 deletions(-) > > diff --git a/libmultipath/alias.c b/libmultipath/alias.c > index 02bc9d6..ad7e512 100644 > --- a/libmultipath/alias.c > +++ b/libmultipath/alias.c > @@ -22,7 +22,7 @@ > #include "util.h" > #include "errno.h" > #include "devmapper.h" > - > +#include "strbuf.h" > > /* > * significant parts of this file were taken from iscsi-bindings.c of the > @@ -61,31 +61,23 @@ valid_alias(const char *alias) > return 1; > } > > - > -static int > -format_devname(char *name, int id, int len, const char *prefix) > +static int format_devname(struct strbuf *buf, int id) > { > - int pos; > - int prefix_len = strlen(prefix); > + /* > + * We need: 7 chars for 32bit integers, 14 chars for 64bit integers > + */ > + char devname[2 * sizeof(int)]; > + int pos = sizeof(devname) - 1, rc; > > - if (len <= prefix_len + 1 || id <= 0) > + if (id <= 0) > return -1; > > - memset(name, 0, len); > - strcpy(name, prefix); > - name[len - 1] = '\0'; > - for (pos = len - 2; pos >= prefix_len; pos--) { > - id--; > - name[pos] = 'a' + id % 26; > - if (id < 26) > - break; > - id /= 26; > - } > - if (pos < prefix_len) > - return -1; > + devname[pos] = '\0'; > + for (; id >= 1; id /= 26) > + devname[--pos] = 'a' + --id % 26; > > - memmove(name + prefix_len, name + pos, len - pos); > - return (prefix_len + len - pos - 1); > + rc = append_strbuf_str(buf, devname + pos); > + return rc >= 0 ? rc : -1; > } > > static int > @@ -123,11 +115,14 @@ scan_devname(const char *alias, const char *prefix) > static int > id_already_taken(int id, const char *prefix, const char *map_wwid) > { > - char alias[LINE_MAX]; > + STRBUF_ON_STACK(buf); > + const char *alias; > > - if (format_devname(alias, id, LINE_MAX, prefix) < 0) > + if (append_strbuf_str(&buf, prefix) < 0 || > + format_devname(&buf, id) < 0) > return 0; > > + alias = get_strbuf_str(&buf); > if (dm_map_present(alias)) { > char wwid[WWID_SIZE]; > > @@ -285,10 +280,10 @@ rlookup_binding(FILE *f, char *buff, const char *map_alias) > static char * > allocate_binding(int fd, const char *wwid, int id, const char *prefix) > { > - char buf[LINE_MAX]; > + STRBUF_ON_STACK(buf); > off_t offset; > + ssize_t len; > char *alias, *c; > - int i; > > if (id <= 0) { > condlog(0, "%s: cannot allocate new binding for id %d", > @@ -296,16 +291,12 @@ allocate_binding(int fd, const char *wwid, int id, const char *prefix) > return NULL; > } > > - i = format_devname(buf, id, LINE_MAX, prefix); > - if (i == -1) > + if (append_strbuf_str(&buf, prefix) < 0 || > + format_devname(&buf, id) == -1) > return NULL; > > - c = buf + i; > - if (snprintf(c, LINE_MAX - i, " %s\n", wwid) >= LINE_MAX - i) { > - condlog(1, "%s: line too long for %s\n", __func__, wwid); > + if (print_strbuf(&buf, " %s\n", wwid) < 0) > return NULL; > - } > - buf[LINE_MAX - 1] = '\0'; > > offset = lseek(fd, 0, SEEK_END); > if (offset < 0){ > @@ -313,24 +304,25 @@ allocate_binding(int fd, const char *wwid, int id, const char *prefix) > strerror(errno)); > return NULL; > } > - if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)){ > + > + len = get_strbuf_len(&buf); > + alias = steal_strbuf_str(&buf); > + > + if (write(fd, alias, len) != len) { > condlog(0, "Cannot write binding to bindings file : %s", > strerror(errno)); > /* clear partial write */ > if (ftruncate(fd, offset)) > condlog(0, "Cannot truncate the header : %s", > strerror(errno)); > + free(alias); > return NULL; > } > - c = strchr(buf, ' '); > + c = strchr(alias, ' '); > if (c) > *c = '\0'; > > - condlog(3, "Created new binding [%s] for WWID [%s]", buf, wwid); > - alias = strdup(buf); > - if (alias == NULL) > - condlog(0, "cannot copy new alias from bindings file: out of memory"); > - > + condlog(3, "Created new binding [%s] for WWID [%s]", alias, wwid); > return alias; > } > > @@ -560,7 +552,7 @@ static int add_binding(Bindings *bindings, const char *alias, const char *wwid) > static int write_bindings_file(const Bindings *bindings, int fd) > { > struct binding *bnd; > - char line[LINE_MAX]; > + STRBUF_ON_STACK(line); > int i; > > if (write(fd, BINDINGS_FILE_HEADER, sizeof(BINDINGS_FILE_HEADER) - 1) > @@ -570,16 +562,12 @@ static int write_bindings_file(const Bindings *bindings, int fd) > vector_foreach_slot(bindings, bnd, i) { > int len; > > - len = snprintf(line, sizeof(line), "%s %s\n", > - bnd->alias, bnd->wwid); > - > - if (len < 0 || (size_t)len >= sizeof(line)) { > - condlog(1, "%s: line overflow", __func__); > + if ((len = print_strbuf(&line, "%s %s\n", > + bnd->alias, bnd->wwid)) < 0) > return -1; > - } > - > - if (write(fd, line, len) != len) > + if (write(fd, get_strbuf_str(&line), len) != len) > return -1; > + truncate_strbuf(&line, 0); > } > return 0; > } > diff --git a/tests/alias.c b/tests/alias.c > index 7e7c187..3ca6c28 100644 > --- a/tests/alias.c > +++ b/tests/alias.c > @@ -81,12 +81,25 @@ int __wrap_dm_get_uuid(const char *name, char *uuid, int uuid_len) > return ret; > } > > +/* strbuf wrapper for the old format_devname() */ > +static int __format_devname(char *name, int id, size_t len, const char *prefix) > +{ > + STRBUF_ON_STACK(buf); > + > + if (append_strbuf_str(&buf, prefix) < 0 || > + format_devname(&buf, id) < 0 || > + len <= get_strbuf_len(&buf)) > + return -1; > + strcpy(name, get_strbuf_str(&buf)); > + return get_strbuf_len(&buf); > +} > + > static void fd_mpatha(void **state) > { > char buf[32]; > int rc; > > - rc = format_devname(buf, 1, sizeof(buf), "FOO"); > + rc = __format_devname(buf, 1, sizeof(buf), "FOO"); > assert_int_equal(rc, 4); > assert_string_equal(buf, "FOOa"); > } > @@ -97,7 +110,7 @@ static void fd_mpathz(void **state) > char buf[5]; > int rc; > > - rc = format_devname(buf, 26, sizeof(buf), "FOO"); > + rc = __format_devname(buf, 26, sizeof(buf), "FOO"); > assert_int_equal(rc, 4); > assert_string_equal(buf, "FOOz"); > } > @@ -107,7 +120,7 @@ static void fd_mpathaa(void **state) > char buf[32]; > int rc; > > - rc = format_devname(buf, 26 + 1, sizeof(buf), "FOO"); > + rc = __format_devname(buf, 26 + 1, sizeof(buf), "FOO"); > assert_int_equal(rc, 5); > assert_string_equal(buf, "FOOaa"); > } > @@ -117,7 +130,7 @@ static void fd_mpathzz(void **state) > char buf[32]; > int rc; > > - rc = format_devname(buf, 26*26 + 26, sizeof(buf), "FOO"); > + rc = __format_devname(buf, 26*26 + 26, sizeof(buf), "FOO"); > assert_int_equal(rc, 5); > assert_string_equal(buf, "FOOzz"); > } > @@ -127,7 +140,7 @@ static void fd_mpathaaa(void **state) > char buf[32]; > int rc; > > - rc = format_devname(buf, 26*26 + 27, sizeof(buf), "FOO"); > + rc = __format_devname(buf, 26*26 + 27, sizeof(buf), "FOO"); > assert_int_equal(rc, 6); > assert_string_equal(buf, "FOOaaa"); > } > @@ -137,7 +150,7 @@ static void fd_mpathzzz(void **state) > char buf[32]; > int rc; > > - rc = format_devname(buf, 26*26*26 + 26*26 + 26, sizeof(buf), "FOO"); > + rc = __format_devname(buf, 26*26*26 + 26*26 + 26, sizeof(buf), "FOO"); > assert_int_equal(rc, 6); > assert_string_equal(buf, "FOOzzz"); > } > @@ -147,7 +160,7 @@ static void fd_mpathaaaa(void **state) > char buf[32]; > int rc; > > - rc = format_devname(buf, 26*26*26 + 26*26 + 27, sizeof(buf), "FOO"); > + rc = __format_devname(buf, 26*26*26 + 26*26 + 27, sizeof(buf), "FOO"); > assert_int_equal(rc, 7); > assert_string_equal(buf, "FOOaaaa"); > } > @@ -157,7 +170,7 @@ static void fd_mpathzzzz(void **state) > char buf[32]; > int rc; > > - rc = format_devname(buf, 26*26*26*26 + 26*26*26 + 26*26 + 26, > + rc = __format_devname(buf, 26*26*26*26 + 26*26*26 + 26*26 + 26, > sizeof(buf), "FOO"); > assert_int_equal(rc, 7); > assert_string_equal(buf, "FOOzzzz"); > @@ -169,7 +182,7 @@ static void fd_mpath_max(void **state) > char buf[32]; > int rc; > > - rc = format_devname(buf, INT_MAX, sizeof(buf), ""); > + rc = __format_devname(buf, INT_MAX, sizeof(buf), ""); > assert_int_equal(rc, strlen(MPATH_ID_INT_MAX)); > assert_string_equal(buf, MPATH_ID_INT_MAX); > } > @@ -180,7 +193,7 @@ static void fd_mpath_max1(void **state) > char buf[32]; > int rc; > > - rc = format_devname(buf, INT_MIN, sizeof(buf), ""); > + rc = __format_devname(buf, INT_MIN, sizeof(buf), ""); > assert_int_equal(rc, -1); > } > > @@ -189,7 +202,7 @@ static void fd_mpath_short(void **state) > char buf[4]; > int rc; > > - rc = format_devname(buf, 1, sizeof(buf), "FOO"); > + rc = __format_devname(buf, 1, sizeof(buf), "FOO"); > assert_int_equal(rc, -1); > } > > @@ -198,7 +211,7 @@ static void fd_mpath_short1(void **state) > char buf[5]; > int rc; > > - rc = format_devname(buf, 27, sizeof(buf), "FOO"); > + rc = __format_devname(buf, 27, sizeof(buf), "FOO"); > assert_int_equal(rc, -1); > } > > @@ -323,7 +336,7 @@ static void sd_fd_many(void **state) > int rc, i; > > for (i = 1; i < 5000; i++) { > - rc = format_devname(buf, i, sizeof(buf), "MPATH"); > + rc = __format_devname(buf, i, sizeof(buf), "MPATH"); > assert_in_range(rc, 6, 8); > rc = scan_devname(buf, "MPATH"); > assert_int_equal(rc, i); > @@ -338,7 +351,7 @@ static void sd_fd_random(void **state) > srandom(1); > for (i = 1; i < 1000; i++) { > n = random() & 0xffff; > - rc = format_devname(buf, n, sizeof(buf), "MPATH"); > + rc = __format_devname(buf, n, sizeof(buf), "MPATH"); > assert_in_range(rc, 6, 9); > rc = scan_devname(buf, "MPATH"); > assert_int_equal(rc, n); > -- > 2.32.0 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel