Hey Steve,
My apologies for dropping this.
I'm a bit confused since the man page for sysconf [1] seems to say it
returns -1 and sets errno to EINVAL (and indeed the patch I originally
submitted shows the intended behaviour on my musl system).
The snippet in the newly defined [get_pwnam_buflen] is pretty much
just what's in the [getpwnam] man page [2] example.
Maybe the thing you're pointing to is that I have [*size_t* buflen =
sysconf(_SC_GETPW_R_SIZE_MAX)].
I guess that should technically be [long buflen] and the result could
be converted to [size_t] upon return, it's just that the implicit
conversions make it such that the current code behaves as expected.
So something like
long buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
if (buflen == -1)
buflen = 16384;
return (size_t)buflen;
Does that make more sense?
[1] https://www.man7.org/linux/man-pages/man3/sysconf.3.html
[2] https://www.man7.org/linux/man-pages/man3/getpwnam.3.html
Best,
Bogdan
On Sat, Nov 9, 2024 at 6:25 PM Steve Dickson <steved@xxxxxxxxxx> wrote:
>
>
>
> On 6/17/24 2:51 PM, Steve Dickson wrote:
> >
> >
> > On 5/30/24 2:17 AM, Bogdan-Cristian Tătăroiu wrote:
> >> sysconf(_SC_GETPW_R_SIZE_MAX) and sysconf(_SC_GETGR_R_SIZE_MAX)
> >> return -1 on musl, which causes either segmentation faults or ENOMEM
> >> errors.
> > Actually sysconf() returns EINVAL not -1 since the return
> > value is a size_t (unsigned long). So I needed to change
> >
> > size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> > if (buflen == EINVAL) <<< this from -1 to EINVAL
> > buflen = 16384;
> > return buflen;
> >
> > Good with that? Will this work with musl?
> Just found this on my todo list... Still
> interest in have these patch committed?
>
> steved.
>
> >
> > steved.
> >
> >>
> >> Replace all usages of sysconf with dedicated methods that guard against
> >> a result of -1.
> >>
> >> Signed-off-by: Bogdan-Cristian Tătăroiu <b.tataroiu@xxxxxxxxx>
> >> ---
> >> support/nfsidmap/gums.c | 4 ++--
> >> support/nfsidmap/libnfsidmap.c | 4 ++--
> >> support/nfsidmap/nfsidmap_common.c | 16 ++++++++++++++++
> >> support/nfsidmap/nfsidmap_private.h | 2 ++
> >> support/nfsidmap/nss.c | 8 ++++----
> >> support/nfsidmap/regex.c | 9 +++++----
> >> support/nfsidmap/static.c | 5 +++--
> >> 7 files changed, 34 insertions(+), 14 deletions(-)
> >>
> >> diff --git a/support/nfsidmap/gums.c b/support/nfsidmap/gums.c
> >> index 1d6eb318..e94a4c50 100644
> >> --- a/support/nfsidmap/gums.c
> >> +++ b/support/nfsidmap/gums.c
> >> @@ -475,7 +475,7 @@ static int translate_to_uid(char *local_uid, uid_t
> >> *uid, uid_t *gid)
> >> int ret = -1;
> >> struct passwd *pw = NULL;
> >> struct pwbuf *buf = NULL;
> >> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> >> + size_t buflen = get_pwnam_buflen();
> >> buf = malloc(sizeof(*buf) + buflen);
> >> if (buf == NULL)
> >> @@ -501,7 +501,7 @@ static int translate_to_gid(char *local_gid, uid_t
> >> *gid)
> >> struct group *gr = NULL;
> >> struct group grbuf;
> >> char *buf = NULL;
> >> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> >> + size_t buflen = get_grnam_buflen();
> >> int ret = -1;
> >> do {
> >> diff --git a/support/nfsidmap/libnfsidmap.c b/support/nfsidmap/
> >> libnfsidmap.c
> >> index f8c36480..e1475879 100644
> >> --- a/support/nfsidmap/libnfsidmap.c
> >> +++ b/support/nfsidmap/libnfsidmap.c
> >> @@ -457,7 +457,7 @@ int nfs4_init_name_mapping(char *conffile)
> >> nobody_user = conf_get_str("Mapping", "Nobody-User");
> >> if (nobody_user) {
> >> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> >> + size_t buflen = get_pwnam_buflen();
> >> struct passwd *buf;
> >> struct passwd *pw = NULL;
> >> int err;
> >> @@ -478,7 +478,7 @@ int nfs4_init_name_mapping(char *conffile)
> >> nobody_group = conf_get_str("Mapping", "Nobody-Group");
> >> if (nobody_group) {
> >> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> >> + size_t buflen = get_grnam_buflen();
> >> struct group *buf;
> >> struct group *gr = NULL;
> >> int err;
> >> diff --git a/support/nfsidmap/nfsidmap_common.c b/support/nfsidmap/
> >> nfsidmap_common.c
> >> index 4d2cb14f..310c68f0 100644
> >> --- a/support/nfsidmap/nfsidmap_common.c
> >> +++ b/support/nfsidmap/nfsidmap_common.c
> >> @@ -116,3 +116,19 @@ int get_reformat_group(void)
> >> return reformat_group;
> >> }
> >> +
> >> +size_t get_pwnam_buflen(void)
> >> +{
> >> + size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> >> + if (buflen == -1)
> >> + buflen = 16384;
> >> + return buflen;
> >> +}
> >> +
> >> +size_t get_grnam_buflen(void)
> >> +{
> >> + size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> >> + if (buflen == -1)
> >> + buflen = 16384;
> >> + return buflen;
> >> +}
> >> diff --git a/support/nfsidmap/nfsidmap_private.h b/support/nfsidmap/
> >> nfsidmap_private.h
> >> index a5cb6dda..234ca9d4 100644
> >> --- a/support/nfsidmap/nfsidmap_private.h
> >> +++ b/support/nfsidmap/nfsidmap_private.h
> >> @@ -40,6 +40,8 @@ struct conf_list *get_local_realms(void);
> >> void free_local_realms(void);
> >> int get_nostrip(void);
> >> int get_reformat_group(void);
> >> +size_t get_pwnam_buflen(void);
> >> +size_t get_grnam_buflen(void);
> >> typedef enum {
> >> IDTYPE_USER = 1,
> >> diff --git a/support/nfsidmap/nss.c b/support/nfsidmap/nss.c
> >> index 0f43076e..3fc045dc 100644
> >> --- a/support/nfsidmap/nss.c
> >> +++ b/support/nfsidmap/nss.c
> >> @@ -91,7 +91,7 @@ static int nss_uid_to_name(uid_t uid, char *domain,
> >> char *name, size_t len)
> >> struct passwd *pw = NULL;
> >> struct passwd pwbuf;
> >> char *buf;
> >> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> >> + size_t buflen = get_pwnam_buflen();
> >> int err = -ENOMEM;
> >> buf = malloc(buflen);
> >> @@ -119,7 +119,7 @@ static int nss_gid_to_name(gid_t gid, char
> >> *domain, char *name, size_t len)
> >> struct group *gr = NULL;
> >> struct group grbuf;
> >> char *buf;
> >> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> >> + size_t buflen = get_grnam_buflen();
> >> int err;
> >> if (domain == NULL)
> >> @@ -192,7 +192,7 @@ static struct passwd *nss_getpwnam(const char
> >> *name, const char *domain,
> >> {
> >> struct passwd *pw;
> >> struct pwbuf *buf;
> >> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> >> + size_t buflen = get_pwnam_buflen();
> >> char *localname;
> >> int err = ENOMEM;
> >> @@ -301,7 +301,7 @@ static int _nss_name_to_gid(char *name, gid_t
> >> *gid, int dostrip)
> >> struct group *gr = NULL;
> >> struct group grbuf;
> >> char *buf, *domain;
> >> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> >> + size_t buflen = get_grnam_buflen();
> >> int err = -EINVAL;
> >> char *localname = NULL;
> >> char *ref_name = NULL;
> >> diff --git a/support/nfsidmap/regex.c b/support/nfsidmap/regex.c
> >> index 8424179f..ea094b95 100644
> >> --- a/support/nfsidmap/regex.c
> >> +++ b/support/nfsidmap/regex.c
> >> @@ -46,6 +46,7 @@
> >> #include "nfsidmap.h"
> >> #include "nfsidmap_plugin.h"
> >> +#include "nfsidmap_private.h"
> >> #define CONFIG_GET_STRING nfsidmap_config_get
> >> extern const char *nfsidmap_config_get(const char *, const char *);
> >> @@ -95,7 +96,7 @@ static struct passwd *regex_getpwnam(const char
> >> *name, const char *UNUSED(domain
> >> {
> >> struct passwd *pw;
> >> struct pwbuf *buf;
> >> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> >> + size_t buflen = get_pwnam_buflen();
> >> char *localname;
> >> size_t namelen;
> >> int err;
> >> @@ -175,7 +176,7 @@ static struct group *regex_getgrnam(const char
> >> *name, const char *UNUSED(domain)
> >> {
> >> struct group *gr;
> >> struct grbuf *buf;
> >> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> >> + size_t buflen = get_grnam_buflen();
> >> char *localgroup;
> >> char *groupname;
> >> size_t namelen;
> >> @@ -366,7 +367,7 @@ static int regex_uid_to_name(uid_t uid, char
> >> *domain, char *name, size_t len)
> >> struct passwd *pw = NULL;
> >> struct passwd pwbuf;
> >> char *buf;
> >> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> >> + size_t buflen = get_pwnam_buflen();
> >> int err = -ENOMEM;
> >> buf = malloc(buflen);
> >> @@ -392,7 +393,7 @@ static int regex_gid_to_name(gid_t gid, char
> >> *UNUSED(domain), char *name, size_t
> >> struct group grbuf;
> >> char *buf;
> >> const char *name_prefix;
> >> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> >> + size_t buflen = get_grnam_buflen();
> >> int err;
> >> char * groupname = NULL;
> >> diff --git a/support/nfsidmap/static.c b/support/nfsidmap/static.c
> >> index 8ac4a398..395cac06 100644
> >> --- a/support/nfsidmap/static.c
> >> +++ b/support/nfsidmap/static.c
> >> @@ -44,6 +44,7 @@
> >> #include "conffile.h"
> >> #include "nfsidmap.h"
> >> #include "nfsidmap_plugin.h"
> >> +#include "nfsidmap_private.h"
> >> /*
> >> * Static Translation Methods
> >> @@ -98,7 +99,7 @@ static struct passwd *static_getpwnam(const char *name,
> >> {
> >> struct passwd *pw;
> >> struct pwbuf *buf;
> >> - size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
> >> + size_t buflen = get_pwnam_buflen();
> >> char *localname;
> >> int err;
> >> @@ -149,7 +150,7 @@ static struct group *static_getgrnam(const char
> >> *name,
> >> {
> >> struct group *gr;
> >> struct grbuf *buf;
> >> - size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
> >> + size_t buflen = get_grnam_buflen();
> >> char *localgroup;
> >> int err;
>
