#include <config.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#include <isc/platform.h>
#include <isc/strerror.h>
#ifdef ISC_PLATFORM_NEEDSYSSELECTH
#include <sys/select.h>
#endif
#include "errno2result.h"
#define FILESOURCE_HANDLE_TYPE int
#include "../entropy.c"
static unsigned int
get_from_filesource(isc_entropysource_t *source, isc_uint32_t desired) {
isc_entropy_t *ent = source->ent;
unsigned char buf[128];
int fd = source->sources.file.handle;
ssize_t n, ndesired;
unsigned int added;
if (source->bad)
return (0);
desired = desired / 8 + (((desired & 0x07) > 0) ? 1 : 0);
added = 0;
while (desired > 0) {
ndesired = ISC_MIN(desired, sizeof(buf));
n = read(fd, buf, ndesired);
if (n < 0) {
if (errno == EAGAIN || errno == EINTR)
goto out;
close(fd);
source->bad = ISC_TRUE;
goto out;
}
if (n == 0) {
close(fd);
source->bad = ISC_TRUE;
goto out;
}
entropypool_adddata(ent, buf, n, n * 8);
added += n * 8;
desired -= n;
}
out:
return (added);
}
static void
fillpool(isc_entropy_t *ent, unsigned int desired, isc_boolean_t blocking) {
unsigned int added;
unsigned int remaining;
unsigned int needed;
unsigned int nsource;
isc_entropysource_t *source;
REQUIRE(VALID_ENTROPY(ent));
needed = desired;
if (needed == 0) {
REQUIRE(!blocking);
if ((ent->pool.entropy >= RND_POOLBITS / 4)
&& (ent->pool.pseudo <= RND_POOLBITS / 4))
return;
needed = THRESHOLD_BITS * 4;
} else {
needed = ISC_MAX(needed, THRESHOLD_BITS);
needed = ISC_MIN(needed, RND_POOLBITS);
}
needed = ISC_MIN(needed, RND_POOLBITS - ent->pool.entropy);
if (ent->initialized < THRESHOLD_BITS)
needed = ISC_MAX(needed, THRESHOLD_BITS - ent->initialized);
added = 0;
remaining = needed;
if (ent->nextsource == NULL) {
ent->nextsource = ISC_LIST_HEAD(ent->sources);
if (ent->nextsource == NULL)
return;
}
source = ent->nextsource;
again_file:
for (nsource = 0 ; nsource < ent->nsources ; nsource++) {
unsigned int got;
if (remaining == 0)
break;
got = 0;
if (source->type == ENTROPY_SOURCETYPE_FILE)
got = get_from_filesource(source, remaining);
added += got;
remaining -= ISC_MIN(remaining, got);
source = ISC_LIST_NEXT(source, link);
if (source == NULL)
source = ISC_LIST_HEAD(ent->sources);
}
ent->nextsource = source;
if (blocking && remaining != 0) {
int fds;
fds = wait_for_sources(ent);
if (fds > 0)
goto again_file;
}
source = ISC_LIST_HEAD(ent->sources);
while ((remaining != 0) && (source != NULL)) {
unsigned int got;
got = 0;
if (source->type == ENTROPY_SOURCETYPE_CALLBACK)
got = get_from_callback(source, remaining, blocking);
added += got;
remaining -= ISC_MIN(remaining, got);
if (added >= needed)
break;
source = ISC_LIST_NEXT(source, link);
}
if (ent->initialized < THRESHOLD_BITS)
ent->initialized += added;
}
static int
wait_for_sources(isc_entropy_t *ent) {
isc_entropysource_t *source;
int maxfd, fd;
int cc;
fd_set reads;
maxfd = -1;
FD_ZERO(&reads);
source = ISC_LIST_HEAD(ent->sources);
while (source != NULL) {
if (source->type == ENTROPY_SOURCETYPE_FILE) {
fd = source->sources.file.handle;
if (fd >= 0) {
maxfd = ISC_MAX(maxfd, fd);
FD_SET(fd, &reads);
}
}
source = ISC_LIST_NEXT(source, link);
}
if (maxfd < 0)
return (-1);
cc = select(maxfd + 1, &reads, NULL, NULL, NULL);
if (cc < 0)
return (-1);
return (cc);
}
static void
destroyfilesource(isc_entropyfilesource_t *source) {
close(source->handle);
}
static isc_result_t
make_nonblock(int fd) {
int ret;
int flags;
char strbuf[ISC_STRERRORSIZE];
flags = fcntl(fd, F_GETFL, 0);
flags |= O_NONBLOCK;
ret = fcntl(fd, F_SETFL, flags);
if (ret == -1) {
isc__strerror(errno, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"fcntl(%d, F_SETFL, %d): %s",
fd, flags, strbuf);
return (ISC_R_UNEXPECTED);
}
return (ISC_R_SUCCESS);
}
isc_result_t
isc_entropy_createfilesource(isc_entropy_t *ent, const char *fname) {
int fd;
isc_result_t ret;
isc_entropysource_t *source;
REQUIRE(VALID_ENTROPY(ent));
REQUIRE(fname != NULL);
LOCK(&ent->lock);
source = NULL;
fd = open(fname, O_RDONLY | O_NONBLOCK, 0);
if (fd < 0) {
ret = isc__errno2result(errno);
goto errout;
}
ret = make_nonblock(fd);
if (ret != ISC_R_SUCCESS)
goto closefd;
source = isc_mem_get(ent->mctx, sizeof(isc_entropysource_t));
if (source == NULL) {
ret = ISC_R_NOMEMORY;
goto closefd;
}
source->magic = SOURCE_MAGIC;
source->type = ENTROPY_SOURCETYPE_FILE;
source->ent = ent;
source->total = 0;
source->bad = ISC_FALSE;
memset(source->name, 0, sizeof(source->name));
ISC_LINK_INIT(source, link);
source->sources.file.handle = fd;
ISC_LIST_APPEND(ent->sources, source, link);
ent->nsources++;
UNLOCK(&ent->lock);
return (ISC_R_SUCCESS);
closefd:
close(fd);
errout:
if (source != NULL)
isc_mem_put(ent->mctx, source, sizeof(isc_entropysource_t));
UNLOCK(&ent->lock);
return (ret);
}