/*
* Getent implements the functions of cgetent. If fp is non-NULL,
* *db_array has already been opened and fp is the open file descriptor. We
* do this to save time and avoid using up file descriptors for tc=
* recursions.
*
* Getent returns the same success/failure codes as cgetent. On success, a
* pointer to a malloc'ed capability record with all tc= capabilities fully
* expanded and its length (not including trailing ASCII NUL) are left in
* *cap and *len.
*
* Basic algorithm:
* + Allocate memory incrementally as needed in chunks of size BFRAG
* for capability buffer.
* + Recurse for each tc=name and interpolate result. Stop when all
* names interpolated, a name can't be found, or depth exceeds
* MAX_RECURSION.
*/
static int
getent(char **cap, u_int *len, char **db_array, FILE *fp,
const char *name, int depth, char *nfield)
{
DB *capdbp;
char *r_end, *rp, **db_p;
int myfd, eof, foundit, opened, retval, clen;
char *record, *cbuf;
int tc_not_resolved;
char pbuf[PATH_MAX];
/*
* Return with ``loop detected'' error if we've recursed more than
* MAX_RECURSION times.
*/
if (depth > MAX_RECURSION)
return (-3);
opened = 0;
/*
* Check if we have a top record from cgetset().
*/
if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) {
opened++;
if ((record = malloc(topreclen + 1 + BFRAG)) == NULL)
return (-2);
memcpy(record, toprec, topreclen + 1);
myfd = 0;
db_p = db_array;
rp = record + topreclen + 1;
r_end = rp + BFRAG;
goto tc_exp;
}
/*
* Allocate first chunk of memory.
*/
if ((record = malloc(BFRAG)) == NULL)
return (-2);
r_end = record + BFRAG;
foundit = 0;
/*
* Loop through database array until finding the record.
*/
for (db_p = db_array; *db_p != NULL; db_p++) {
eof = 0;
/*
* Open database if not already open.
*/
if (fp != NULL) {
(void)fseek(fp, 0L, SEEK_SET);
myfd = 0;
opened++;
} else {
char *dbrecord;
clen = snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p);
if (clen != -1 && clen < sizeof(pbuf) && usedb &&
(capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0))) {
opened++;
retval = cdbget(capdbp, &dbrecord, name);
if (retval < 0) {
/* no record available */
(void)capdbp->close(capdbp);
continue;
}
free(record);
/* save the data; close frees it */
clen = strlen(dbrecord);
if ((cbuf = malloc(clen + 1)) == NULL)
return (-2);
memcpy(cbuf, dbrecord, clen + 1);
if (capdbp->close(capdbp) < 0) {
free(cbuf);
return (-2);
}
/* assume tc='s have been expanded??? */
*len = clen;
*cap = cbuf;
return (retval);
} else {
fp = fopen(*db_p, "re");
if (fp == NULL) {
/* No error on unfound file. */
continue;
}
myfd = 1;
opened++;
}
}
/*
* Find the requested capability record ...
*/
{
char buf[BUFSIZ];
char *b_end, *bp;
int c;
/*
* Loop invariants:
* There is always room for one more character in record.
* R_end always points just past end of record.
* Rp always points just past last character in record.
* B_end always points just past last character in buf.
* Bp always points at next character in buf.
*/
b_end = buf;
bp = buf;
for (;;) {
/*
* Read in a line implementing (\, newline)
* line continuation.
*/
rp = record;
for (;;) {
if (bp >= b_end) {
size_t n;
n = fread(buf, 1, sizeof(buf), fp);
if (n == 0) {
eof = feof(fp);
if (myfd)
(void)fclose(fp);
if (eof) {
fp = NULL;
break;
}
free(record);
return (-2);
}
b_end = buf+n;
bp = buf;
}
c = *bp++;
if (c == '\n') {
if (rp > record && *(rp-1) == '\\') {
rp--;
continue;
} else
break;
}
*rp++ = c;
/*
* Enforce loop invariant: if no room
* left in record buffer, try to get
* some more.
*/
if (rp >= r_end) {
size_t pos;
size_t newsize;
char *nrecord;
pos = rp - record;
newsize = r_end - record + BFRAG;
nrecord = realloc(record, newsize);
if (nrecord == NULL) {
free(record);
if (myfd)
(void)fclose(fp);
errno = ENOMEM;
return (-2);
}
record = nrecord;
r_end = record + newsize;
rp = record + pos;
}
}
/* loop invariant lets us do this */
*rp++ = '\0';
/*
* If encountered EOF check next file.
*/
if (eof)
break;
/*
* Toss blank lines and comments.
*/
if (*record == '\0' || *record == '#')
continue;
/*
* See if this is the record we want ...
*/
if (cgetmatch(record, name) == 0) {
if (nfield == NULL || !nfcmp(nfield, record)) {
foundit = 1;
break; /* found it! */
}
}
}
}
if (foundit)
break;
}
if (!foundit) {
free(record);
return (opened ? -1 : -2);
}
/*
* Got the capability record, but now we have to expand all tc=name
* references in it ...
*/
tc_exp: {
char *s;
u_int ilen;
int diff, iret, tclen;
char *ibuf, *icap, *scan, *tc, *tcstart, *tcend;
/*
* Loop invariants:
* There is room for one more character in record.
* R_end points just past end of record.
* Rp points just past last character in record.
* Scan points at remainder of record that needs to be
* scanned for tc=name constructs.
*/
scan = record;
tc_not_resolved = 0;
for (;;) {
if ((tc = cgetcap(scan, "tc", '=')) == NULL)
break;
/*
* Find end of tc=name and stomp on the trailing `:'
* (if present) so we can use it to call ourselves.
*/
s = tc;
for (;;) {
if (*s == '\0')
break;
else
if (*s++ == ':') {
*(s - 1) = '\0';
break;
}
}
tcstart = tc - 3;
tclen = s - tcstart;
tcend = s;
iret = getent(&icap, &ilen, db_p, fp, tc, depth+1,
NULL);
if (iret != 0) {
/* an error */
if (iret < -1) {
if (myfd)
(void)fclose(fp);
free(record);
return (iret);
}
if (iret == 1)
tc_not_resolved = 1;
/* couldn't resolve tc */
if (iret == -1) {
*(s - 1) = ':';
scan = s - 1;
tc_not_resolved = 1;
continue;
}
}
/* not interested in name field of tc'ed record */
s = ibuf = icap;
for (;;)
if (*s == '\0')
break;
else
if (*s++ == ':')
break;
ilen -= s - icap;
icap = s;
/* make sure interpolated record is `:'-terminated */
s += ilen;
if (*(s-1) != ':') {
*s = ':'; /* overwrite NUL with : */
ilen++;
}
/*
* Make sure there's enough room to insert the
* new record.
*/
diff = ilen - tclen;
if (diff >= r_end - rp) {
u_int pos, tcpos, tcposend;
size_t newsize;
char *nrecord;
pos = rp - record;
newsize = r_end - record + diff + BFRAG;
tcpos = tcstart - record;
tcposend = tcend - record;
nrecord = realloc(record, newsize);
if (nrecord == NULL) {
free(record);
if (myfd)
(void)fclose(fp);
free(ibuf);
errno = ENOMEM;
return (-2);
}
record = nrecord;
r_end = record + newsize;
rp = record + pos;
tcstart = record + tcpos;
tcend = record + tcposend;
}
/*
* Insert tc'ed record into our record.
*/
s = tcstart + ilen;
memmove(s, tcend, rp - tcend);
memmove(tcstart, icap, ilen);
rp += diff;
free(ibuf);
/*
* Start scan on `:' so next cgetcap works properly
* (cgetcap always skips first field).
*/
scan = s-1;
}
}
/*
* Close file (if we opened it), give back any extra memory, and
* return capability, length and success.
*/
if (myfd)
(void)fclose(fp);
*len = rp - record - 1; /* don't count NUL */
if (r_end > rp) {
char *nrecord;
if ((nrecord = realloc(record, rp - record)) == NULL) {
free(record);
errno = ENOMEM;
return (-2);
}
record = nrecord;
}
*cap = record;
if (tc_not_resolved)
return (1);
return (0);
}
/*
* Getent implements the functions of cgetent. If fd is non-negative,
* *db_array has already been opened and fd is the open file descriptor. We
* do this to save time and avoid using up file descriptors for tc=
* recursions.
*
* Getent returns the same success/failure codes as cgetent. On success, a
* pointer to a malloc'ed capability record with all tc= capabilities fully
* expanded and its length (not including trailing ASCII NUL) are left in
* *cap and *len.
*
* Basic algorithm:
* + Allocate memory incrementally as needed in chunks of size BFRAG
* for capability buffer.
* + Recurse for each tc=name and interpolate result. Stop when all
* names interpolated, a name can't be found, or depth exceeds
* MAX_RECURSION.
*/
static int
getent(char **cap, size_t *len, char **db_array, int fd,
const char *name, int depth, char *nfield)
{
char *r_end, *rp = NULL, **db_p; /* pacify gcc */
int myfd = 0, eof, foundit;
char *record;
int tc_not_resolved;
/*
* Return with ``loop detected'' error if we've recursed more than
* MAX_RECURSION times.
*/
if (depth > MAX_RECURSION)
return (-3);
/*
* Check if we have a top record from cgetset().
*/
if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) {
size_t len = topreclen + BFRAG;
if ((record = malloc (len)) == NULL) {
errno = ENOMEM;
return (-2);
}
(void)strlcpy(record, toprec, len);
db_p = db_array;
rp = record + topreclen + 1;
r_end = rp + BFRAG;
goto tc_exp;
}
/*
* Allocate first chunk of memory.
*/
if ((record = malloc(BFRAG)) == NULL) {
errno = ENOMEM;
return (-2);
}
r_end = record + BFRAG;
foundit = 0;
/*
* Loop through database array until finding the record.
*/
for (db_p = db_array; *db_p != NULL; db_p++) {
eof = 0;
/*
* Open database if not already open.
*/
if (fd >= 0) {
(void)lseek(fd, (off_t)0, SEEK_SET);
} else {
#ifdef USE_DB
char pbuf[_POSIX_PATH_MAX];
char *cbuf;
size_t clen;
int retval;
DB *capdbp;
(void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p);
if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0))
!= NULL) {
free(record);
retval = cdbget(capdbp, &record, name);
if (retval < 0) {
/* no record available */
(void)capdbp->close(capdbp);
return (retval);
}
/* save the data; close frees it */
clen = strlen(record);
cbuf = malloc(clen + 1);
if (cbuf == NULL)
return (-2);
memmove(cbuf, record, clen + 1);
if (capdbp->close(capdbp) < 0) {
free(cbuf);
return (-2);
}
*len = clen;
*cap = cbuf;
return (retval);
} else
#endif
{
fd = open(*db_p, O_RDONLY, 0);
if (fd < 0) {
/* No error on unfound file. */
continue;
}
myfd = 1;
}
}
/*
* Find the requested capability record ...
*/
{
char buf[BUFSIZ];
char *b_end, *bp, *cp;
int c, slash;
/*
* Loop invariants:
* There is always room for one more character in record.
* R_end always points just past end of record.
* Rp always points just past last character in record.
* B_end always points just past last character in buf.
* Bp always points at next character in buf.
* Cp remembers where the last colon was.
*/
b_end = buf;
bp = buf;
cp = 0;
slash = 0;
for (;;) {
/*
* Read in a line implementing (\, newline)
* line continuation.
*/
rp = record;
for (;;) {
if (bp >= b_end) {
int n;
n = read(fd, buf, sizeof(buf));
if (n <= 0) {
if (myfd)
(void)close(fd);
if (n < 0) {
free(record);
return (-2);
} else {
fd = -1;
eof = 1;
break;
}
}
b_end = buf+n;
bp = buf;
}
c = *bp++;
if (c == '\n') {
if (slash) {
slash = 0;
rp--;
continue;
} else
break;
}
if (slash) {
slash = 0;
cp = 0;
}
if (c == ':') {
/*
* If the field was `empty' (i.e.
* contained only white space), back up
* to the colon (eliminating the
* field).
*/
if (cp)
rp = cp;
else
cp = rp;
} else if (c == '\\') {
slash = 1;
} else if (c != ' ' && c != '\t') {
/*
* Forget where the colon was, as this
* is not an empty field.
*/
cp = 0;
}
*rp++ = c;
/*
* Enforce loop invariant: if no room
* left in record buffer, try to get
* some more.
*/
if (rp >= r_end) {
u_int pos;
size_t newsize;
pos = rp - record;
newsize = r_end - record + BFRAG;
record = realloc(record, newsize);
if (record == NULL) {
errno = ENOMEM;
if (myfd)
(void)close(fd);
return (-2);
}
r_end = record + newsize;
rp = record + pos;
}
}
/* Eliminate any white space after the last colon. */
if (cp)
rp = cp + 1;
/* Loop invariant lets us do this. */
*rp++ = '\0';
/*
* If encountered eof check next file.
*/
if (eof)
break;
/*
* Toss blank lines and comments.
*/
if (*record == '\0' || *record == '#')
continue;
/*
* See if this is the record we want ...
*/
if (cgetmatch(record, name) == 0) {
if (nfield == NULL || !nfcmp(nfield, record)) {
foundit = 1;
break; /* found it! */
}
}
}
}
if (foundit)
break;
}
if (!foundit)
return (-1);
/*
* Got the capability record, but now we have to expand all tc=name
* references in it ...
*/
tc_exp: {
char *newicap, *s;
size_t ilen, newilen;
int diff, iret, tclen;
char *icap, *scan, *tc, *tcstart, *tcend;
/*
* Loop invariants:
* There is room for one more character in record.
* R_end points just past end of record.
* Rp points just past last character in record.
* Scan points at remainder of record that needs to be
* scanned for tc=name constructs.
*/
scan = record;
tc_not_resolved = 0;
for (;;) {
if ((tc = cgetcap(scan, "tc", '=')) == NULL)
break;
/*
* Find end of tc=name and stomp on the trailing `:'
* (if present) so we can use it to call ourselves.
*/
s = tc;
for (;;)
if (*s == '\0')
break;
else
if (*s++ == ':') {
*(s - 1) = '\0';
break;
}
tcstart = tc - 3;
tclen = s - tcstart;
tcend = s;
iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
NULL);
newicap = icap; /* Put into a register. */
newilen = ilen;
if (iret != 0) {
/* an error */
if (iret < -1) {
if (myfd)
(void)close(fd);
free(record);
return (iret);
}
if (iret == 1)
tc_not_resolved = 1;
/* couldn't resolve tc */
if (iret == -1) {
*(s - 1) = ':';
scan = s - 1;
tc_not_resolved = 1;
continue;
}
}
/* not interested in name field of tc'ed record */
s = newicap;
for (;;)
if (*s == '\0')
break;
else
if (*s++ == ':')
break;
newilen -= s - newicap;
newicap = s;
/* make sure interpolated record is `:'-terminated */
s += newilen;
if (*(s-1) != ':') {
*s = ':'; /* overwrite NUL with : */
newilen++;
}
/*
* Make sure there's enough room to insert the
* new record.
*/
diff = newilen - tclen;
if (diff >= r_end - rp) {
u_int pos, tcpos, tcposend;
size_t newsize;
pos = rp - record;
newsize = r_end - record + diff + BFRAG;
tcpos = tcstart - record;
tcposend = tcend - record;
record = realloc(record, newsize);
if (record == NULL) {
errno = ENOMEM;
if (myfd)
(void)close(fd);
free(icap);
return (-2);
}
r_end = record + newsize;
rp = record + pos;
tcstart = record + tcpos;
tcend = record + tcposend;
}
/*
* Insert tc'ed record into our record.
*/
s = tcstart + newilen;
memmove(s, tcend, (size_t)(rp - tcend));
memmove(tcstart, newicap, newilen);
rp += diff;
free(icap);
/*
* Start scan on `:' so next cgetcap works properly
* (cgetcap always skips first field).
*/
scan = s-1;
}
}
/*
* Close file (if we opened it), give back any extra memory, and
* return capability, length and success.
*/
if (myfd)
(void)close(fd);
*len = rp - record - 1; /* don't count NUL */
if (r_end > rp)
if ((record =
realloc(record, (size_t)(rp - record))) == NULL) {
errno = ENOMEM;
return (-2);
}
*cap = record;
if (tc_not_resolved)
return (1);
return (0);
}