Date: Sat, 9 Mar 2013 13:30:06 +0000 (UTC) From: Diane Bruce <db@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r248102 - head/lib/libutil Message-ID: <201303091330.r29DU6s1067101@svn.freebsd.org>
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Author: db (ports committer) Date: Sat Mar 9 13:30:06 2013 New Revision: 248102 URL: http://svnweb.freebsd.org/changeset/base/248102 Log: commit correct tested fix for gr_util.c Approved by: theraven Modified: head/lib/libutil/gr_util.c Modified: head/lib/libutil/gr_util.c ============================================================================== --- head/lib/libutil/gr_util.c Sat Mar 9 13:25:45 2013 (r248101) +++ head/lib/libutil/gr_util.c Sat Mar 9 13:30:06 2013 (r248102) @@ -50,7 +50,7 @@ static char group_file[PATH_MAX]; static char tempname[PATH_MAX]; static int initialized; static size_t grmemlen(const struct group *, const char *, int *); -static struct group *grcopy(const struct group *gr, struct group *newgr, const char *, int ndx); +static struct group *grcopy(const struct group *gr, char *mem, const char *, int ndx); /* * Initialize statics @@ -361,26 +361,30 @@ gr_equal(const struct group *gr1, const if (gr1->gr_gid != gr2->gr_gid) return (false); - /* Check all members in both groups. */ - if (gr1->gr_mem == NULL || gr2->gr_mem == NULL) { - if (gr1->gr_mem != gr2->gr_mem) - return (false); - } else { - for (gr1_ndx = 0; gr1->gr_mem[gr1_ndx] != NULL; gr1_ndx++) { - for (gr2_ndx = 0;; gr2_ndx++) { - if (gr2->gr_mem[gr2_ndx] == NULL) - return (false); - if (strcmp(gr1->gr_mem[gr1_ndx], - gr2->gr_mem[gr2_ndx]) == 0) { - break; - } - } - } - - /* Check that group2 does not have more members than group1. */ - if (gr2->gr_mem[gr1_ndx] != NULL) - return (false); - } + /* Check all members in both groups. + * getgrnam can return gr_mem with a pointer to NULL. + * gr_dup and gr_add strip out this superfluous NULL, setting + * gr_mem to NULL for no members. + */ + if (gr1->gr_mem != NULL && gr2->gr_mem != NULL) { + int i; + + for (i = 0; gr1->gr_mem[i] != NULL; i++) { + if (strcmp(gr1->gr_mem[i], gr2->gr_mem[i]) != 0) + return (false); + } + } + /* Count number of members in both structs */ + gr2_ndx = 0; + if (gr2->gr_mem != NULL) + for(; gr2->gr_mem[gr2_ndx] != NULL; gr2_ndx++) + /* empty */; + gr1_ndx = 0; + if (gr1->gr_mem != NULL) + for(; gr1->gr_mem[gr1_ndx] != NULL; gr1_ndx++) + /* empty */; + if (gr1_ndx != gr2_ndx) + return (false); return (true); } @@ -439,21 +443,21 @@ gr_dup(const struct group *gr) struct group * gr_add(const struct group *gr, const char *newmember) { - struct group *newgr; + char *mem; size_t len; int num_mem; num_mem = 0; len = grmemlen(gr, newmember, &num_mem); /* Create new group and copy old group into it. */ - if ((newgr = malloc(len)) == NULL) + if ((mem = malloc(len)) == NULL) return (NULL); - return (grcopy(gr, newgr, newmember, num_mem)); + return (grcopy(gr, mem, newmember, num_mem)); } /* It is safer to walk the pointers given at gr_mem since there is no - * guarantee the gr_mem + strings are continguous in the given struct group - * but compact the new group into the following form. + * guarantee the gr_mem + strings are contiguous in the given struct group + * but compactify the new group into the following form. * * The new struct is laid out like this in memory. The example given is * for a group with two members only. @@ -474,23 +478,21 @@ gr_add(const struct group *gr, const cha * } */ /* - * Copy the guts of a group plus given name to a preallocated group struct + * Copy the contents of a group plus given name to a preallocated group struct */ static struct group * -grcopy(const struct group *gr, struct group *newgr, const char *name, int ndx) +grcopy(const struct group *gr, char *dst, const char *name, int ndx) { - char *dst; int i; + struct group *newgr; - if (name != NULL) - ndx++; - /* point new gr_mem to end of struct + 1 if there are names */ - if (ndx != 0) - newgr->gr_mem = (char **)(newgr + 1); - else + newgr = (struct group *)(void *)dst; /* avoid alignment warning */ + dst += sizeof(*newgr); + if (ndx != 0) { + newgr->gr_mem = (char **)(void *)(dst); /* avoid alignment warning */ + dst += (ndx + 1) * sizeof(*newgr->gr_mem); + } else newgr->gr_mem = NULL; - /* point dst after the end of all the gr_mem pointers in newgr */ - dst = (char *)&newgr->gr_mem[ndx + 1]; if (gr->gr_name != NULL) { newgr->gr_name = dst; dst = stpcpy(dst, gr->gr_name) + 1; @@ -502,17 +504,23 @@ grcopy(const struct group *gr, struct gr } else newgr->gr_passwd = NULL; newgr->gr_gid = gr->gr_gid; - if (ndx != 0) { - for (i = 0; gr->gr_mem[i] != NULL; i++) { + i = 0; + /* Original group struct might have a NULL gr_mem */ + if (gr->gr_mem != NULL) { + for (; gr->gr_mem[i] != NULL; i++) { newgr->gr_mem[i] = dst; dst = stpcpy(dst, gr->gr_mem[i]) + 1; } - if (name != NULL) { - newgr->gr_mem[i++] = dst; - dst = stpcpy(dst, name) + 1; - } - newgr->gr_mem[i] = NULL; } + /* If name is not NULL, newgr->gr_mem is known to be not NULL */ + if (name != NULL) { + newgr->gr_mem[i++] = dst; + dst = stpcpy(dst, name) + 1; + } + /* if newgr->gr_mem is not NULL add NULL marker */ + if (newgr->gr_mem != NULL) + newgr->gr_mem[i] = NULL; + return (newgr); } @@ -533,18 +541,22 @@ grmemlen(const struct group *gr, const c len += strlen(gr->gr_name) + 1; if (gr->gr_passwd != NULL) len += strlen(gr->gr_passwd) + 1; + i = 0; if (gr->gr_mem != NULL) { - for (len = i = 0; gr->gr_mem[i] != NULL; i++) { + for (; gr->gr_mem[i] != NULL; i++) { len += strlen(gr->gr_mem[i]) + 1; len += sizeof(*gr->gr_mem); } - *num_mem = i; } if (name != NULL) { + i++; len += strlen(name) + 1; - if (gr->gr_mem == NULL) - len += sizeof(*gr->gr_mem); + len += sizeof(*gr->gr_mem); } + /* Allow for NULL pointer */ + if (i != 0) + len += sizeof(*gr->gr_mem); + *num_mem = i; return(len); }
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