diff options
Diffstat (limited to 'eBones/acl/acl_files.c')
| -rw-r--r-- | eBones/acl/acl_files.c | 555 |
1 files changed, 0 insertions, 555 deletions
diff --git a/eBones/acl/acl_files.c b/eBones/acl/acl_files.c deleted file mode 100644 index a3e1f68..0000000 --- a/eBones/acl/acl_files.c +++ /dev/null @@ -1,555 +0,0 @@ -/* - * - * Copyright 1987,1989 by the Massachusetts Institute of Technology. - * - * For copying and distribution information, please see the file - * <mit-copyright.h>. - * - * from: acl_files.c,v 4.4 89/12/19 13:30:53 jtkohl Exp $ - * $Id: acl_files.c,v 1.3 1995/07/18 16:34:49 mark Exp $ - */ - -#if 0 -#ifndef lint -static char rcsid[] = -"$Id: acl_files.c,v 1.3 1995/07/18 16:34:49 mark Exp $"; -#endif lint -#endif - - -/*** Routines for manipulating access control list files ***/ - -#include <unistd.h> -#include <stdlib.h> -#include <stdio.h> -#include <strings.h> -#include <sys/file.h> -#include <sys/types.h> -#include <sys/stat.h> -#include <sys/errno.h> -#include <ctype.h> -#include "krb.h" - -__BEGIN_DECLS -static int acl_abort __P((char *, FILE *)); -__END_DECLS - -#ifndef KRB_REALM -#define KRB_REALM "ATHENA.MIT.EDU" -#endif - -/* "aname.inst@realm" */ -#define MAX_PRINCIPAL_SIZE (ANAME_SZ + INST_SZ + REALM_SZ + 3) -#define INST_SEP '.' -#define REALM_SEP '@' - -#define LINESIZE 2048 /* Maximum line length in an acl file */ - -#define NEW_FILE "%s.~NEWACL~" /* Format for name of altered acl file */ -#define WAIT_TIME 300 /* Maximum time allowed write acl file */ - -#define CACHED_ACLS 8 /* How many acls to cache */ - /* Each acl costs 1 open file descriptor */ -#define ACL_LEN 16 /* Twice a reasonable acl length */ - -#define MAX(a,b) (((a)>(b))?(a):(b)) -#define MIN(a,b) (((a)<(b))?(a):(b)) - -#define COR(a,b) ((a!=NULL)?(a):(b)) - -/* Canonicalize a principal name */ -/* If instance is missing, it becomes "" */ -/* If realm is missing, it becomes the local realm */ -/* Canonicalized form is put in canon, which must be big enough to hold - MAX_PRINCIPAL_SIZE characters */ -void -acl_canonicalize_principal(principal, canon) -char *principal; -char *canon; -{ - char *dot, *atsign, *end; - int len; - - dot = index(principal, INST_SEP); - atsign = index(principal, REALM_SEP); - - /* Maybe we're done already */ - if(dot != NULL && atsign != NULL) { - if(dot < atsign) { - /* It's for real */ - /* Copy into canon */ - strncpy(canon, principal, MAX_PRINCIPAL_SIZE); - canon[MAX_PRINCIPAL_SIZE-1] = '\0'; - return; - } else { - /* Nope, it's part of the realm */ - dot = NULL; - } - } - - /* No such luck */ - end = principal + strlen(principal); - - /* Get the principal name */ - len = MIN(ANAME_SZ, COR(dot, COR(atsign, end)) - principal); - strncpy(canon, principal, len); - canon += len; - - /* Add INST_SEP */ - *canon++ = INST_SEP; - - /* Get the instance, if it exists */ - if(dot != NULL) { - ++dot; - len = MIN(INST_SZ, COR(atsign, end) - dot); - strncpy(canon, dot, len); - canon += len; - } - - /* Add REALM_SEP */ - *canon++ = REALM_SEP; - - /* Get the realm, if it exists */ - /* Otherwise, default to local realm */ - if(atsign != NULL) { - ++atsign; - len = MIN(REALM_SZ, end - atsign); - strncpy(canon, atsign, len); - canon += len; - *canon++ = '\0'; - } else if(krb_get_lrealm(canon, 1) != KSUCCESS) { - strcpy(canon, KRB_REALM); - } -} - -/* Get a lock to modify acl_file */ -/* Return new FILE pointer */ -/* or NULL if file cannot be modified */ -/* REQUIRES WRITE PERMISSION TO CONTAINING DIRECTORY */ -static FILE * -acl_lock_file(acl_file) -char *acl_file; -{ - struct stat s; - char new[LINESIZE]; - int nfd; - FILE *nf; - int mode; - - if(stat(acl_file, &s) < 0) return(NULL); - mode = s.st_mode; - sprintf(new, NEW_FILE, acl_file); - for(;;) { - /* Open the new file */ - if((nfd = open(new, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0) { - if(errno == EEXIST) { - /* Maybe somebody got here already, maybe it's just old */ - if(stat(new, &s) < 0) return(NULL); - if(time(0) - s.st_ctime > WAIT_TIME) { - /* File is stale, kill it */ - unlink(new); - continue; - } else { - /* Wait and try again */ - sleep(1); - continue; - } - } else { - /* Some other error, we lose */ - return(NULL); - } - } - - /* If we got to here, the lock file is ours and ok */ - /* Reopen it under stdio */ - if((nf = fdopen(nfd, "w")) == NULL) { - /* Oops, clean up */ - unlink(new); - } - return(nf); - } -} - -/* Commit changes to acl_file written onto FILE *f */ -/* Returns zero if successful */ -/* Returns > 0 if lock was broken */ -/* Returns < 0 if some other error occurs */ -/* Closes f */ -static int -acl_commit(acl_file, f) -char *acl_file; -FILE *f; -{ - char new[LINESIZE]; - int ret; - struct stat s; - - sprintf(new, NEW_FILE, acl_file); - if(fflush(f) < 0 - || fstat(fileno(f), &s) < 0 - || s.st_nlink == 0) { - acl_abort(acl_file, f); - return(-1); - } - - ret = rename(new, acl_file); - fclose(f); - return(ret); -} - -/* - * Abort changes to acl_file written onto FILE *f - * Returns 0 if successful, < 0 otherwise - * Closes f - */ -static int -acl_abort(acl_file, f) -char *acl_file; -FILE *f; -{ - char new[LINESIZE]; - int ret; - struct stat s; - - /* make sure we aren't nuking someone else's file */ - if(fstat(fileno(f), &s) < 0 || s.st_nlink == 0) { - fclose(f); - return(-1); - } else { - sprintf(new, NEW_FILE, acl_file); - ret = unlink(new); - fclose(f); - return(ret); - } -} - -/* Initialize an acl_file */ -/* Creates the file with permissions perm if it does not exist */ -/* Erases it if it does */ -/* Returns return value of acl_commit */ -int -acl_initialize(acl_file, perm) -char *acl_file; -int perm; -{ - FILE *new; - int fd; - - /* Check if the file exists already */ - if((new = acl_lock_file(acl_file)) != NULL) { - return(acl_commit(acl_file, new)); - } else { - /* File must be readable and writable by owner */ - if((fd = open(acl_file, O_CREAT|O_EXCL, perm|0600)) < 0) { - return(-1); - } else { - close(fd); - return(0); - } - } -} - -/* Eliminate all whitespace character in buf */ -/* Modifies its argument */ -static void -nuke_whitespace(buf) -char *buf; -{ - register char *pin, *pout; - - for(pin = pout = buf; *pin != '\0'; pin++) - if(!isspace(*pin)) *pout++ = *pin; - *pout = '\0'; /* Terminate the string */ -} - -/* Hash table stuff */ - -struct hashtbl { - int size; /* Max number of entries */ - int entries; /* Actual number of entries */ - char **tbl; /* Pointer to start of table */ -}; - -/* Make an empty hash table of size s */ -static struct hashtbl * -make_hash(size) -int size; -{ - struct hashtbl *h; - - if(size < 1) size = 1; - h = (struct hashtbl *) malloc(sizeof(struct hashtbl)); - h->size = size; - h->entries = 0; - h->tbl = (char **) calloc(size, sizeof(char *)); - return(h); -} - -/* Destroy a hash table */ -static void -destroy_hash(h) -struct hashtbl *h; -{ - int i; - - for(i = 0; i < h->size; i++) { - if(h->tbl[i] != NULL) free(h->tbl[i]); - } - free(h->tbl); - free(h); -} - -/* Compute hash value for a string */ -static unsigned -hashval(s) -register char *s; -{ - register unsigned hv; - - for(hv = 0; *s != '\0'; s++) { - hv ^= ((hv << 3) ^ *s); - } - return(hv); -} - -/* Add an element to a hash table */ -static void -add_hash(h, el) -struct hashtbl *h; -char *el; -{ - unsigned hv; - char *s; - char **old; - int i; - - /* Make space if it isn't there already */ - if(h->entries + 1 > (h->size >> 1)) { - old = h->tbl; - h->tbl = (char **) calloc(h->size << 1, sizeof(char *)); - for(i = 0; i < h->size; i++) { - if(old[i] != NULL) { - hv = hashval(old[i]) % (h->size << 1); - while(h->tbl[hv] != NULL) hv = (hv+1) % (h->size << 1); - h->tbl[hv] = old[i]; - } - } - h->size = h->size << 1; - free(old); - } - - hv = hashval(el) % h->size; - while(h->tbl[hv] != NULL && strcmp(h->tbl[hv], el)) hv = (hv+1) % h->size; - s = malloc(strlen(el)+1); - strcpy(s, el); - h->tbl[hv] = s; - h->entries++; -} - -/* Returns nonzero if el is in h */ -static int -check_hash(h, el) -struct hashtbl *h; -char *el; -{ - unsigned hv; - - for(hv = hashval(el) % h->size; - h->tbl[hv] != NULL; - hv = (hv + 1) % h->size) { - if(!strcmp(h->tbl[hv], el)) return(1); - } - return(0); -} - -struct acl { - char filename[LINESIZE]; /* Name of acl file */ - int fd; /* File descriptor for acl file */ - struct stat status; /* File status at last read */ - struct hashtbl *acl; /* Acl entries */ -}; - -static struct acl acl_cache[CACHED_ACLS]; - -static int acl_cache_count = 0; -static int acl_cache_next = 0; - -/* Returns < 0 if unsuccessful in loading acl */ -/* Returns index into acl_cache otherwise */ -/* Note that if acl is already loaded, this is just a lookup */ -static int -acl_load(name) -char *name; -{ - int i; - FILE *f; - struct stat s; - char buf[MAX_PRINCIPAL_SIZE]; - char canon[MAX_PRINCIPAL_SIZE]; - - /* See if it's there already */ - for(i = 0; i < acl_cache_count; i++) { - if(!strcmp(acl_cache[i].filename, name) - && acl_cache[i].fd >= 0) goto got_it; - } - - /* It isn't, load it in */ - /* maybe there's still room */ - if(acl_cache_count < CACHED_ACLS) { - i = acl_cache_count++; - } else { - /* No room, clean one out */ - i = acl_cache_next; - acl_cache_next = (acl_cache_next + 1) % CACHED_ACLS; - close(acl_cache[i].fd); - if(acl_cache[i].acl) { - destroy_hash(acl_cache[i].acl); - acl_cache[i].acl = (struct hashtbl *) 0; - } - } - - /* Set up the acl */ - strcpy(acl_cache[i].filename, name); - if((acl_cache[i].fd = open(name, O_RDONLY, 0)) < 0) return(-1); - /* Force reload */ - acl_cache[i].acl = (struct hashtbl *) 0; - - got_it: - /* - * See if the stat matches - * - * Use stat(), not fstat(), as the file may have been re-created by - * acl_add or acl_delete. If this happens, the old inode will have - * no changes in the mod-time and the following test will fail. - */ - if(stat(acl_cache[i].filename, &s) < 0) return(-1); - if(acl_cache[i].acl == (struct hashtbl *) 0 - || s.st_nlink != acl_cache[i].status.st_nlink - || s.st_mtime != acl_cache[i].status.st_mtime - || s.st_ctime != acl_cache[i].status.st_ctime) { - /* Gotta reload */ - if(acl_cache[i].fd >= 0) close(acl_cache[i].fd); - if((acl_cache[i].fd = open(name, O_RDONLY, 0)) < 0) return(-1); - if((f = fdopen(acl_cache[i].fd, "r")) == NULL) return(-1); - if(acl_cache[i].acl) destroy_hash(acl_cache[i].acl); - acl_cache[i].acl = make_hash(ACL_LEN); - while(fgets(buf, sizeof(buf), f) != NULL) { - nuke_whitespace(buf); - acl_canonicalize_principal(buf, canon); - add_hash(acl_cache[i].acl, canon); - } - fclose(f); - acl_cache[i].status = s; - } - return(i); -} - -/* Returns nonzero if it can be determined that acl contains principal */ -/* Principal is not canonicalized, and no wildcarding is done */ -int -acl_exact_match(acl, principal) -char *acl; -char *principal; -{ - int idx; - - return((idx = acl_load(acl)) >= 0 - && check_hash(acl_cache[idx].acl, principal)); -} - -/* Returns nonzero if it can be determined that acl contains principal */ -/* Recognizes wildcards in acl of the form - name.*@realm, *.*@realm, and *.*@* */ -int -acl_check(acl, principal) -char *acl; -char *principal; -{ - char buf[MAX_PRINCIPAL_SIZE]; - char canon[MAX_PRINCIPAL_SIZE]; - char *realm; - - acl_canonicalize_principal(principal, canon); - - /* Is it there? */ - if(acl_exact_match(acl, canon)) return(1); - - /* Try the wildcards */ - realm = index(canon, REALM_SEP); - *index(canon, INST_SEP) = '\0'; /* Chuck the instance */ - - sprintf(buf, "%s.*%s", canon, realm); - if(acl_exact_match(acl, buf)) return(1); - - sprintf(buf, "*.*%s", realm); - if(acl_exact_match(acl, buf) || acl_exact_match(acl, "*.*@*")) return(1); - - return(0); -} - -/* Adds principal to acl */ -/* Wildcards are interpreted literally */ -int -acl_add(acl, principal) -char *acl; -char *principal; -{ - int idx; - int i; - FILE *new; - char canon[MAX_PRINCIPAL_SIZE]; - - acl_canonicalize_principal(principal, canon); - - if((new = acl_lock_file(acl)) == NULL) return(-1); - if((acl_exact_match(acl, canon)) - || (idx = acl_load(acl)) < 0) { - acl_abort(acl, new); - return(-1); - } - /* It isn't there yet, copy the file and put it in */ - for(i = 0; i < acl_cache[idx].acl->size; i++) { - if(acl_cache[idx].acl->tbl[i] != NULL) { - if(fputs(acl_cache[idx].acl->tbl[i], new) == NULL - || putc('\n', new) != '\n') { - acl_abort(acl, new); - return(-1); - } - } - } - fputs(canon, new); - putc('\n', new); - return(acl_commit(acl, new)); -} - -/* Removes principal from acl */ -/* Wildcards are interpreted literally */ -int -acl_delete(acl, principal) -char *acl; -char *principal; -{ - int idx; - int i; - FILE *new; - char canon[MAX_PRINCIPAL_SIZE]; - - acl_canonicalize_principal(principal, canon); - - if((new = acl_lock_file(acl)) == NULL) return(-1); - if((!acl_exact_match(acl, canon)) - || (idx = acl_load(acl)) < 0) { - acl_abort(acl, new); - return(-1); - } - /* It isn't there yet, copy the file and put it in */ - for(i = 0; i < acl_cache[idx].acl->size; i++) { - if(acl_cache[idx].acl->tbl[i] != NULL - && strcmp(acl_cache[idx].acl->tbl[i], canon)) { - fputs(acl_cache[idx].acl->tbl[i], new); - putc('\n', new); - } - } - return(acl_commit(acl, new)); -} - |
