/**
* nsm_get_state - retrieve on-disk NSM state number
*
* Returns an odd NSM state number read from disk, or an initial
* state number. Zero is returned if some error occurs.
*/
int
nsm_get_state(_Bool update)
{
int fd, state = 0;
ssize_t result;
char *path = NULL;
path = nsm_make_pathname(NSM_STATE_FILE);
if (path == NULL) {
xlog(L_ERROR, "Failed to allocate path for " NSM_STATE_FILE);
goto out;
}
fd = open(path, O_RDONLY);
if (fd == -1) {
if (errno != ENOENT) {
xlog(L_ERROR, "Failed to open %s: %m", path);
goto out;
}
xlog(L_NOTICE, "Initializing NSM state");
state = 1;
update = true;
goto update;
}
result = read(fd, &state, sizeof(state));
if (exact_error_check(result, sizeof(state))) {
xlog_warn("Failed to read %s: %m", path);
xlog(L_NOTICE, "Initializing NSM state");
state = 1;
update = true;
goto update;
}
if ((state & 1) == 0)
state++;
update:
if(fd >= 0)
(void)close(fd);
if (update) {
state += 2;
if (!nsm_atomic_write(path, &state, sizeof(state)))
state = 0;
}
out:
free(path);
return state;
}
static _Bool
nsm_append_monitored_host(const char *path, const char *line)
{
_Bool result = false;
char *buf = NULL;
struct stat stb;
size_t buflen;
ssize_t len;
int fd;
if (stat(path, &stb) == -1) {
xlog(L_ERROR, "Failed to insert: "
"could not stat original file %s: %m", path);
goto out;
}
buflen = (size_t)stb.st_size + strlen(line);
buf = malloc(buflen + 1);
if (buf == NULL) {
xlog(L_ERROR, "Failed to insert: no memory");
goto out;
}
memset(buf, 0, buflen + 1);
fd = open(path, O_RDONLY);
if (fd == -1) {
xlog(L_ERROR, "Failed to insert: "
"could not open original file %s: %m", path);
goto out;
}
len = read(fd, buf, (size_t)stb.st_size);
if (exact_error_check(len, (size_t)stb.st_size)) {
xlog(L_ERROR, "Failed to insert: "
"could not read original file %s: %m", path);
(void)close(fd);
goto out;
}
(void)close(fd);
strcat(buf, line);
if (nsm_atomic_write(path, buf, buflen))
result = true;
out:
free(buf);
return result;
}
static void
nsm_delete_host(const char *directory, const char *hostname,
const char *mon_name, const char *my_name)
{
char line[LINELEN + 1 + SM_MAXSTRLEN + 2];
char *outbuf = NULL;
struct stat stb;
char *path, *next;
size_t remaining;
FILE *f;
path = nsm_make_record_pathname(directory, hostname);
if (path == NULL) {
xlog(L_ERROR, "Bad filename, not deleting");
return;
}
if (stat(path, &stb) == -1) {
xlog(L_ERROR, "Failed to delete: "
"could not stat original file %s: %m", path);
goto out;
}
remaining = (size_t)stb.st_size + 1;
outbuf = malloc(remaining);
if (outbuf == NULL) {
xlog(L_ERROR, "Failed to delete: no memory");
goto out;
}
f = fopen(path, "r");
if (f == NULL) {
xlog(L_ERROR, "Failed to delete: "
"could not open original file %s: %m", path);
goto out;
}
/*
* Walk the records in the file, and copy the non-matching
* ones to our output buffer.
*/
next = outbuf;
while (fgets(line, (int)sizeof(line), f) != NULL) {
struct sockaddr_in sin;
struct mon m;
size_t len;
if (!nsm_parse_line(line, &sin, &m)) {
xlog(L_ERROR, "Failed to delete: "
"could not parse original file %s", path);
(void)fclose(f);
goto out;
}
if (strcmp(mon_name, m.mon_id.mon_name) == 0 &&
strcmp(my_name, m.mon_id.my_id.my_name) == 0)
continue;
/* nsm_parse_line destroys the contents of line[], so
* reconstruct the copy in our output buffer. */
len = nsm_create_monitor_record(next, remaining,
(struct sockaddr *)(char *)&sin, &m);
if (len == 0) {
xlog(L_ERROR, "Failed to delete: "
"could not construct output record");
(void)fclose(f);
goto out;
}
next += len;
remaining -= len;
}
(void)fclose(f);
/*
* If nothing was copied when we're done, then unlink the file.
* Otherwise, atomically update the contents of the file.
*/
if (next != outbuf) {
if (!nsm_atomic_write(path, outbuf, strlen(outbuf)))
xlog(L_ERROR, "Failed to delete: "
"could not write new file %s: %m", path);
} else {
if (unlink(path) == -1)
xlog(L_ERROR, "Failed to delete: "
"could not unlink file %s: %m", path);
}
out:
free(outbuf);
free(path);
}