X-Git-Url: https://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fuserspec.c;h=d08ed07165e7e929b5e1a2b894b041de0641911d;hb=6d8337bfc808cddc275899c03482eceb6aff8547;hp=8c1e9ec8ea0680367599ac8945322f216ac05644;hpb=92a0e357d2915935df140c766bf98db53a53a455;p=gnulib.git diff --git a/lib/userspec.c b/lib/userspec.c index 8c1e9ec8e..d08ed0716 100644 --- a/lib/userspec.c +++ b/lib/userspec.c @@ -12,20 +12,27 @@ GNU General Public License for more details. You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + along with this program; if not, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* Written by David MacKenzie . */ #ifdef HAVE_CONFIG_H -#if defined (CONFIG_BROKETS) -/* We use instead of "config.h" so that a compilation - using -I. -I will use ./config.h rather than /config.h - (which it would do because it found this file in ). */ #include -#else -#include "config.h" #endif + +#ifdef __GNUC__ +# define alloca __builtin_alloca +#else +# ifdef HAVE_ALLOCA_H +# include +# else +# ifdef _AIX + #pragma alloca +# else +char *alloca (); +# endif +# endif #endif #include @@ -33,23 +40,21 @@ #include #include -#if defined(STDC_HEADERS) || defined(HAVE_STRING_H) -#include -#ifndef index -#define index strchr -#endif +#ifdef HAVE_STRING_H +# include #else -#include +# include +# ifndef strchr +# define strchr index +# endif #endif #ifdef STDC_HEADERS -#include -#else -char *malloc (); +# include #endif #ifdef HAVE_UNISTD_H -#include +# include #endif #ifndef _POSIX_VERSION @@ -58,15 +63,42 @@ struct group *getgrnam (); struct group *getgrgid (); #endif -#ifdef _POSIX_SOURCE -#define endpwent() -#define endgrent() +#ifndef HAVE_ENDGRENT +# define endgrent() ((void) 0) +#endif + +#ifndef HAVE_ENDPWENT +# define endpwent() ((void) 0) #endif +/* Perform the equivalent of the statement `dest = strdup (src);', + but obtaining storage via alloca instead of from the heap. */ + +#define V_STRDUP(dest, src) \ + do \ + { \ + int _len = strlen ((src)); \ + (dest) = (char *) alloca (_len + 1); \ + strcpy (dest, src); \ + } \ + while (0) + #define isdigit(c) ((c) >= '0' && (c) <= '9') char *strdup (); -static int isnumber (); + +/* Return nonzero if STR represents an unsigned decimal integer, + otherwise return 0. */ + +static int +is_number (str) + const char *str; +{ + for (; *str; str++) + if (!isdigit (*str)) + return 0; + return 1; +} /* Extract from NAME, which has the form "[user][:.][group]", a USERNAME, UID U, GROUPNAME, and GID G. @@ -77,115 +109,172 @@ static int isnumber (); USERNAME and GROUPNAME will be in newly malloc'd memory. Either one might be NULL instead, indicating that it was not given and the corresponding numeric ID was left unchanged. - Might write NULs into NAME. Return NULL if successful, a static error message string if not. */ -char * -parse_user_spec (name, uid, gid, username, groupname) - char *name; +const char * +parse_user_spec (spec_arg, uid, gid, username_arg, groupname_arg) + const char *spec_arg; uid_t *uid; gid_t *gid; - char **username, **groupname; + char **username_arg, **groupname_arg; { - static char *tired = "virtual memory exhausted"; + static const char *tired = "virtual memory exhausted"; + const char *error_msg; + char *spec; /* A copy we can write on. */ struct passwd *pwd; struct group *grp; - char *cp; - int use_login_group = 0; + char *g, *u, *separator; + char *groupname; + + error_msg = NULL; + *username_arg = *groupname_arg = NULL; + groupname = NULL; + + V_STRDUP (spec, spec_arg); + + /* Find the separator if there is one. */ + separator = strchr (spec, ':'); + if (separator == NULL) + separator = strchr (spec, '.'); + + /* Replace separator with a NUL. */ + if (separator != NULL) + *separator = '\0'; - *username = *groupname = NULL; + /* Set U and G to non-zero length strings corresponding to user and + group specifiers or to NULL. */ + u = (*spec == '\0' ? NULL : spec); - /* Check whether a group is given. */ - cp = index (name, ':'); - if (cp == NULL) - cp = index (name, '.'); - if (cp != NULL) + g = (separator == NULL || *(separator + 1) == '\0' + ? NULL + : separator + 1); + + if (u == NULL && g == NULL) + return "can not omit both user and group"; + + if (u != NULL) { - *cp++ = '\0'; - if (*cp == '\0') + pwd = getpwnam (u); + if (pwd == NULL) { - if (cp == name + 1) - /* Neither user nor group given, just "." or ":". */ - return "can not omit both user and group"; + + if (!is_number (u)) + error_msg = "invalid user"; else - /* "user.". */ - use_login_group = 1; + { + int use_login_group; + use_login_group = (separator != NULL && g == NULL); + if (use_login_group) + error_msg = "cannot get the login group of a numeric UID"; + else + *uid = atoi (u); + } } else { - /* Explicit group. */ - *groupname = strdup (cp); - if (*groupname == NULL) - return tired; - grp = getgrnam (cp); - if (grp == NULL) + *uid = pwd->pw_uid; + if (g == NULL && separator != NULL) { - if (!isnumber (cp)) - return "invalid group"; - *gid = atoi (cp); + /* A separator was given, but a group was not specified, + so get the login group. */ + *gid = pwd->pw_gid; + grp = getgrgid (pwd->pw_gid); + if (grp == NULL) + { + /* This is enough room to hold the unsigned decimal + representation of any 32-bit quantity and the trailing + zero byte. */ + char uint_buf[21]; + sprintf (uint_buf, "%u", (unsigned) (pwd->pw_gid)); + V_STRDUP (groupname, uint_buf); + } + else + { + V_STRDUP (groupname, grp->gr_name); + } + endgrent (); } - else - *gid = grp->gr_gid; - endgrent (); /* Save a file descriptor. */ } + endpwent (); } - /* Parse the user name, now that any group has been removed. */ - - if (name[0] == '\0') - /* No user name was given, just a group. */ - return NULL; - - *username = strdup (name); - if (*username == NULL) - return tired; - - pwd = getpwnam (name); - if (pwd == NULL) + if (g != NULL && error_msg == NULL) { - if (!isnumber (name)) - return "invalid user"; - if (use_login_group) - return "cannot get the login group of a numeric UID"; - *uid = atoi (name); + /* Explicit group. */ + grp = getgrnam (g); + if (grp == NULL) + { + if (!is_number (g)) + error_msg = "invalid group"; + else + *gid = atoi (g); + } + else + *gid = grp->gr_gid; + endgrent (); /* Save a file descriptor. */ + + if (error_msg == NULL) + V_STRDUP (groupname, g); } - else + + if (error_msg == NULL) { - *uid = pwd->pw_uid; - if (use_login_group) + if (u != NULL) { - *gid = pwd->pw_gid; - grp = getgrgid (pwd->pw_gid); - if (grp == NULL) - { - *groupname = malloc (15); - if (*groupname == NULL) - return tired; - sprintf (*groupname, "%u", pwd->pw_gid); - } - else + *username_arg = strdup (u); + if (*username_arg == NULL) + error_msg = tired; + } + + if (groupname != NULL && error_msg == NULL) + { + *groupname_arg = strdup (groupname); + if (*groupname_arg == NULL) { - *groupname = strdup (grp->gr_name); - if (*groupname == NULL) - return tired; + if (*username_arg != NULL) + { + free (*username_arg); + *username_arg = NULL; + } + error_msg = tired; } - endgrent (); } } - endpwent (); - return NULL; + + return error_msg; } -/* Return nonzero if STR represents an unsigned decimal integer, - otherwise return 0. */ +#ifdef TEST -static int -isnumber (str) - char *str; +#define NULL_CHECK(s) ((s) == NULL ? "(null)" : (s)) + +int +main (int argc, char **argv) { - for (; *str; str++) - if (!isdigit (*str)) - return 0; - return 1; + int i; + + for (i = 1; i < argc; i++) + { + const char *e; + char *username, *groupname; + uid_t uid; + gid_t gid; + char *tmp; + + tmp = strdup (argv[i]); + e = parse_user_spec (tmp, &uid, &gid, &username, &groupname); + free (tmp); + printf ("%s: %u %u %s %s %s\n", + argv[i], + (unsigned int) uid, + (unsigned int) gid, + NULL_CHECK (username), + NULL_CHECK (groupname), + NULL_CHECK (e)); + } + + exit (0); } + +#endif