On Tue, Feb 20, 2018 at 05:07:27PM +0000, Bruce Richardson wrote: > Following on from the number of patches needing to be done for strncpy > issues highlighted by coverity... > > The strncpy function is error prone for doing "safe" string copies, so > we generally try to use "snprintf" instead in the code. The function > "strlcpy" is a better alternative, though, since it better conveys the > intention of the programmer, and doesn't suffer from the non-null > terminating behaviour of it's n'ed brethern. > > The downside of this function is that it is not available by default > on linux, though standard in the BSD's. It is available on most > distros by installing "libbsd" package. > > This RFC therefore provides the following in rte_string_fns.h to ensure > that strlcpy is available there: > * for BSD, include string.h as normal > * if RTE_USE_LIBBSD is set, include <bsd/string.h> > * if not set, fallback to snprintf for strlcpy > > Using make build system, the RTE_USE_LIBBSD is a hard-coded value to "n", > but when using meson, it's automatically set based on what is available > on the platform. > > Instances of snprintf using "%s" alone as a string format are replaced > via coccinelle script with the new strlcpy function. Instances of > strncpy should be replaced too, but requires manual checking as to > whether the NULL termination is manually done afterward or not. > > Signed-off-by: Bruce Richardson <bruce.richard...@intel.com>
OK with the RFC, a few comments below regarding mlx4, mlx5 and the definition itself though. <snip> > diff --git a/drivers/net/mlx4/mlx4_ethdev.c b/drivers/net/mlx4/mlx4_ethdev.c > index 3bc692731..c92dd6d43 100644 > --- a/drivers/net/mlx4/mlx4_ethdev.c > +++ b/drivers/net/mlx4/mlx4_ethdev.c > @@ -120,7 +120,7 @@ mlx4_get_ifname(const struct priv *priv, char > (*ifname)[IF_NAMESIZE]) > goto try_dev_id; > dev_port_prev = dev_port; > if (dev_port == (priv->port - 1u)) > - snprintf(match, sizeof(match), "%s", name); > + strlcpy(match, name, sizeof(match)); > } > closedir(dir); > if (match[0] == '\0') { Missing #include <rte_string_fns.h> > diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c > index 666507691..894a045ec 100644 > --- a/drivers/net/mlx5/mlx5_ethdev.c > +++ b/drivers/net/mlx5/mlx5_ethdev.c > @@ -163,7 +163,7 @@ priv_get_ifname(const struct priv *priv, char > (*ifname)[IF_NAMESIZE]) > goto try_dev_id; > dev_port_prev = dev_port; > if (dev_port == (priv->port - 1u)) > - snprintf(match, sizeof(match), "%s", name); > + strlcpy(match, name, sizeof(match)); > } > closedir(dir); > if (match[0] == '\0') Ditto (note I didn't check missing occurrences in other components). <snip> > diff --git a/lib/librte_eal/common/include/rte_string_fns.h > b/lib/librte_eal/common/include/rte_string_fns.h > index e97047a47..ff4c98b2a 100644 > --- a/lib/librte_eal/common/include/rte_string_fns.h > +++ b/lib/librte_eal/common/include/rte_string_fns.h > @@ -45,6 +45,20 @@ int > rte_strsplit(char *string, int stringlen, > char **tokens, int maxtokens, char delim); > > +/* pull in a strlcpy function */ > +#ifdef RTE_EXEC_ENV_BSDAPP > +#include <string.h> > + > +#else /* non-BSD platforms */ > +#ifdef RTE_USE_LIBBSD > +#include <bsd/string.h> > + > +#else /* no BSD header files, create own */ > +#define strlcpy(dst, src, size) snprintf(dst, size, "%s", src) Missing #include <stdio.h> for that. What also bothers me is that on some platforms, applications get a true function definition and a macro on others. I suggest a static inline or even a proper versioned definition in eal_common_string_fns.c instead. -- Adrien Mazarguil 6WIND