From 9274e94db85bac04e170414cb8e0f4be271cde90 Mon Sep 17 00:00:00 2001 From: Sean Finney Date: Tue, 19 Apr 2011 11:05:47 -0400 Subject: [PATCH] mountd: Use a dynamic buffer for storing lists of gid's Previously, in auth_unix_gid, group lists were stored in an array of hard-coded length 100, and in the situation that the group lists for a particular call were too large, the array was swapped with a dynamically allocated/freed buffer. For environments where users are commonly in a large number of groups, this isn't an ideal approach. Instead, use malloc/realloc to grow the list on an as-needed basis. Signed-off-by: Sean Finney Signed-off-by: Steve Dickson --- utils/mountd/cache.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c index 1d6e953..ce93e3c 100644 --- a/utils/mountd/cache.c +++ b/utils/mountd/cache.c @@ -64,6 +64,7 @@ enum nfsd_fsid { */ static int cache_export_ent(char *domain, struct exportent *exp, char *p); +#define INITIAL_MANAGED_GROUPS 100 char *lbuf = NULL; int lbuflen = 0; @@ -134,11 +135,21 @@ static void auth_unix_gid(FILE *f) */ uid_t uid; struct passwd *pw; - gid_t glist[100], *groups = glist; - int ngroups = 100; + static gid_t *groups = NULL; + static int groups_len = 0; + gid_t *more_groups; + int ngroups = 0; int rv, i; char *cp; + if (groups_len == 0) { + groups = malloc(sizeof(gid_t) * INITIAL_MANAGED_GROUPS); + if (!groups) + return; + + groups_len = ngroups = INITIAL_MANAGED_GROUPS; + } + if (readline(fileno(f), &lbuf, &lbuflen) != 1) return; @@ -151,13 +162,16 @@ static void auth_unix_gid(FILE *f) rv = -1; else { rv = getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups); - if (rv == -1 && ngroups >= 100) { - groups = malloc(sizeof(gid_t)*ngroups); - if (!groups) + if (rv == -1 && ngroups >= groups_len) { + more_groups = realloc(groups, sizeof(gid_t)*ngroups); + if (!more_groups) rv = -1; - else + else { + groups = more_groups; + groups_len = ngroups; rv = getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups); + } } } qword_printuint(f, uid); @@ -169,9 +183,6 @@ static void auth_unix_gid(FILE *f) } else qword_printuint(f, 0); qword_eol(f); - - if (groups != glist) - free(groups); } #if USE_BLKID -- 2.39.2