diff options
| -rw-r--r-- | arch/tile/gxio/mpipe.c | 37 |
1 files changed, 32 insertions, 5 deletions
diff --git a/arch/tile/gxio/mpipe.c b/arch/tile/gxio/mpipe.c index 5301a9ffbae1..320ff5e6e61e 100644 --- a/arch/tile/gxio/mpipe.c +++ b/arch/tile/gxio/mpipe.c @@ -29,6 +29,32 @@ /* HACK: Avoid pointless "shadow" warnings. */ #define link link_shadow +/** + * strscpy - Copy a C-string into a sized buffer, but only if it fits + * @dest: Where to copy the string to + * @src: Where to copy the string from + * @size: size of destination buffer + * + * Use this routine to avoid copying too-long strings. + * The routine returns the total number of bytes copied + * (including the trailing NUL) or zero if the buffer wasn't + * big enough. To ensure that programmers pay attention + * to the return code, the destination has a single NUL + * written at the front (if size is non-zero) when the + * buffer is not big enough. + */ +static size_t strscpy(char *dest, const char *src, size_t size) +{ + size_t len = strnlen(src, size) + 1; + if (len > size) { + if (size) + dest[0] = '\0'; + return 0; + } + memcpy(dest, src, len); + return len; +} + int gxio_mpipe_init(gxio_mpipe_context_t *context, unsigned int mpipe_index) { char file[32]; @@ -511,8 +537,8 @@ int gxio_mpipe_link_instance(const char *link_name) if (!context) return GXIO_ERR_NO_DEVICE; - strncpy(name.name, link_name, sizeof(name.name)); - name.name[GXIO_MPIPE_LINK_NAME_LEN - 1] = '\0'; + if (strscpy(name.name, link_name, sizeof(name.name)) == 0) + return GXIO_ERR_NO_DEVICE; return gxio_mpipe_info_instance_aux(context, name); } @@ -529,7 +555,8 @@ int gxio_mpipe_link_enumerate_mac(int idx, char *link_name, uint8_t *link_mac) rv = gxio_mpipe_info_enumerate_aux(context, idx, &name, &mac); if (rv >= 0) { - strncpy(link_name, name.name, sizeof(name.name)); + if (strscpy(link_name, name.name, sizeof(name.name)) == 0) + return GXIO_ERR_INVAL_MEMORY_SIZE; memcpy(link_mac, mac.mac, sizeof(mac.mac)); } @@ -545,8 +572,8 @@ int gxio_mpipe_link_open(gxio_mpipe_link_t *link, _gxio_mpipe_link_name_t name; int rv; - strncpy(name.name, link_name, sizeof(name.name)); - name.name[GXIO_MPIPE_LINK_NAME_LEN - 1] = '\0'; + if (strscpy(name.name, link_name, sizeof(name.name)) == 0) + return GXIO_ERR_NO_DEVICE; rv = gxio_mpipe_link_open_aux(context, name, flags); if (rv < 0) |