ssize_t fs_config_generate(char *buffer, size_t length, const struct fs_path_config *pc)
{
struct fs_path_config_from_file *p = (struct fs_path_config_from_file *)buffer;
size_t len = ALIGN(sizeof(*p) + strlen(pc->prefix) + 1, sizeof(uint64_t));
if ((length < len) || (len > UINT16_MAX)) {
return -ENOSPC;
}
memset(p, 0, len);
uint16_t host_len = len;
p->len = get2LE((const uint8_t *)&host_len);
p->mode = get2LE((const uint8_t *)&(pc->mode));
p->uid = get2LE((const uint8_t *)&(pc->uid));
p->gid = get2LE((const uint8_t *)&(pc->gid));
p->capabilities = get8LE((const uint8_t *)&(pc->capabilities));
strcpy(p->prefix, pc->prefix);
return len;
}
/*
* Recursively convert binary log data to printable form.
*
* This needs to be recursive because you can have lists of lists.
*
* If we run out of room, we stop processing immediately. It's important
* for us to check for space on every output element to avoid producing
* garbled output.
*
* Returns 0 on success, 1 on buffer full, -1 on failure.
*/
static int android_log_printBinaryEvent(const unsigned char** pEventData,
size_t* pEventDataLen, char** pOutBuf, size_t* pOutBufLen)
{
const unsigned char* eventData = *pEventData;
size_t eventDataLen = *pEventDataLen;
char* outBuf = *pOutBuf;
size_t outBufLen = *pOutBufLen;
unsigned char type;
size_t outCount;
int result = 0;
if (eventDataLen < 1)
return -1;
type = *eventData++;
eventDataLen--;
//fprintf(stderr, "--- type=%d (rem len=%d)\n", type, eventDataLen);
switch (type) {
case EVENT_TYPE_INT:
/* 32-bit signed int */
{
int ival;
if (eventDataLen < 4)
return -1;
ival = get4LE(eventData);
eventData += 4;
eventDataLen -= 4;
outCount = snprintf(outBuf, outBufLen, "%d", ival);
if (outCount < outBufLen) {
outBuf += outCount;
outBufLen -= outCount;
} else {
/* halt output */
goto no_room;
}
}
break;
case EVENT_TYPE_LONG:
/* 64-bit signed long */
{
long long lval;
if (eventDataLen < 8)
return -1;
lval = get8LE(eventData);
eventData += 8;
eventDataLen -= 8;
outCount = snprintf(outBuf, outBufLen, "%lld", lval);
if (outCount < outBufLen) {
outBuf += outCount;
outBufLen -= outCount;
} else {
/* halt output */
goto no_room;
}
}
break;
case EVENT_TYPE_STRING:
/* UTF-8 chars, not NULL-terminated */
{
unsigned int strLen;
if (eventDataLen < 4)
return -1;
strLen = get4LE(eventData);
eventData += 4;
eventDataLen -= 4;
if (eventDataLen < strLen)
return -1;
if (strLen < outBufLen) {
memcpy(outBuf, eventData, strLen);
outBuf += strLen;
outBufLen -= strLen;
} else if (outBufLen > 0) {
/* copy what we can */
memcpy(outBuf, eventData, outBufLen);
outBuf += outBufLen;
outBufLen -= outBufLen;
goto no_room;
}
eventData += strLen;
eventDataLen -= strLen;
break;
}
case EVENT_TYPE_LIST:
/* N items, all different types */
{
unsigned char count;
int i;
if (eventDataLen < 1)
return -1;
count = *eventData++;
eventDataLen--;
if (outBufLen > 0) {
*outBuf++ = '[';
outBufLen--;
} else {
goto no_room;
}
for (i = 0; i < count; i++) {
result = android_log_printBinaryEvent(&eventData, &eventDataLen,
&outBuf, &outBufLen);
if (result != 0)
goto bail;
if (i < count-1) {
if (outBufLen > 0) {
*outBuf++ = ',';
outBufLen--;
} else {
goto no_room;
}
}
}
if (outBufLen > 0) {
*outBuf++ = ']';
outBufLen--;
} else {
goto no_room;
}
}
break;
default:
fprintf(stderr, "Unknown binary event type %d\n", type);
return -1;
}
bail:
*pEventData = eventData;
*pEventDataLen = eventDataLen;
*pOutBuf = outBuf;
*pOutBufLen = outBufLen;
return result;
no_room:
result = 1;
goto bail;
}
void fs_config(const char *path, int dir, const char *target_out_path,
unsigned *uid, unsigned *gid, unsigned *mode, uint64_t *capabilities)
{
const struct fs_path_config *pc;
int fd, plen;
if (path[0] == '/') {
path++;
}
plen = strlen(path);
fd = fs_config_open(dir, target_out_path);
if (fd >= 0) {
struct fs_path_config_from_file header;
while (TEMP_FAILURE_RETRY(read(fd, &header, sizeof(header))) == sizeof(header)) {
char *prefix;
uint16_t host_len = get2LE((const uint8_t *)&header.len);
ssize_t len, remainder = host_len - sizeof(header);
if (remainder <= 0) {
ALOGE("%s len is corrupted", dir ? conf_dir : conf_file);
break;
}
prefix = calloc(1, remainder);
if (!prefix) {
ALOGE("%s out of memory", dir ? conf_dir : conf_file);
break;
}
if (TEMP_FAILURE_RETRY(read(fd, prefix, remainder)) != remainder) {
free(prefix);
ALOGE("%s prefix is truncated", dir ? conf_dir : conf_file);
break;
}
len = strnlen(prefix, remainder);
if (len >= remainder) { /* missing a terminating null */
free(prefix);
ALOGE("%s is corrupted", dir ? conf_dir : conf_file);
break;
}
if (fs_config_cmp(dir, prefix, len, path, plen)) {
free(prefix);
close(fd);
*uid = get2LE((const uint8_t *)&(header.uid));
*gid = get2LE((const uint8_t *)&(header.gid));
*mode = (*mode & (~07777)) | get2LE((const uint8_t *)&(header.mode));
*capabilities = get8LE((const uint8_t *)&(header.capabilities));
return;
}
free(prefix);
}
close(fd);
}
pc = dir ? android_dirs : android_files;
for(; pc->prefix; pc++) {
if (fs_config_cmp(dir, pc->prefix, strlen(pc->prefix), path, plen)) {
break;
}
}
*uid = pc->uid;
*gid = pc->gid;
*mode = (*mode & (~07777)) | pc->mode;
*capabilities = pc->capabilities;
}
