#include <stdlib.h>
#include <limits.h>
#include <string.h>
+#include <errno.h>
#include <ccan/tdb/tdb.h>
+#include <ccan/tdb/tdb_private.h>
+#include <ccan/tap/tap.h>
+#include <stdio.h>
+#include <stdarg.h>
+
+static struct tdb_context *tdb;
static volatile sig_atomic_t alarmed;
static void do_alarm(int signum)
alarmed++;
}
-static int do_transaction(const char *name)
+static void taplog(struct tdb_context *tdb,
+ enum tdb_debug_level level,
+ const char *fmt, ...)
{
+ va_list ap;
+ char line[200];
+
+ va_start(ap, fmt);
+ vsprintf(line, fmt, ap);
+ va_end(ap);
+
+ diag("external: %s", line);
+}
+
+static int do_operation(enum operation op, const char *name)
+{
+ struct tdb_logging_context logctx = { taplog, NULL };
+
TDB_DATA k = { .dptr = (void *)"a", .dsize = 1 };
TDB_DATA d = { .dptr = (void *)"b", .dsize = 1 };
- struct tdb_context *tdb = tdb_open(name, 0, 0, O_RDWR, 0);
- if (!tdb)
- return -1;
+ if (op <= KEEP_OPENED) {
+ tdb = tdb_open_ex(name, 0, op == OPEN_WITH_CLEAR_IF_FIRST ?
+ TDB_CLEAR_IF_FIRST : TDB_DEFAULT, O_RDWR, 0,
+ &logctx, NULL);
+ if (!tdb)
+ return -1;
+ }
+
+ if (op == KEEP_OPENED) {
+ return 0;
+ } else if (op == OPEN || op == OPEN_WITH_CLEAR_IF_FIRST || op == CLOSE) {
+ tdb_close(tdb);
+ tdb = NULL;
+ return 1;
+ } else if (op == STORE_KEEP_OPENED) {
+ if (tdb_store(tdb, k, d, 0) != 0)
+ return -2;
+ return 1;
+ } else if (op == FETCH_KEEP_OPENED) {
+ TDB_DATA ret;
+ ret = tdb_fetch(tdb, k);
+ if (ret.dptr == NULL) {
+ if (tdb_error(tdb) == TDB_ERR_NOEXIST)
+ return 1;
+ return -3;
+ }
+ if (ret.dsize != 1 || *(char *)ret.dptr != 'b')
+ return -4;
+ free(ret.dptr);
+ return 1;
+ } else if (op == CHECK_KEEP_OPENED) {
+ return tdb_check(tdb, NULL, 0) == 0;
+ } else if (op == NEEDS_RECOVERY_KEEP_OPENED) {
+ return tdb_needs_recovery(tdb);
+ }
alarmed = 0;
tdb_setalarm_sigptr(tdb, &alarmed);
if (tdb_transaction_start(tdb) != 0)
goto maybe_alarmed;
+ alarm(0);
if (tdb_store(tdb, k, d, 0) != 0) {
tdb_transaction_cancel(tdb);
tdb_close(tdb);
+ tdb = NULL;
return -2;
}
if (tdb_transaction_commit(tdb) == 0) {
tdb_delete(tdb, k);
- tdb_close(tdb);
+ if (op != TRANSACTION_KEEP_OPENED) {
+ tdb_close(tdb);
+ tdb = NULL;
+ }
return 1;
}
tdb_delete(tdb, k);
maybe_alarmed:
- tdb_close(tdb);
+ if (op != TRANSACTION_KEEP_OPENED) {
+ tdb_close(tdb);
+ tdb = NULL;
+ }
if (alarmed)
return 0;
return -3;
}
+struct agent {
+ int cmdfd, responsefd;
+};
-/* Do this before doing any tdb stuff. Return handle, or -1. */
-int prepare_external_agent(void)
+/* Do this before doing any tdb stuff. Return handle, or NULL. */
+struct agent *prepare_external_agent(void)
{
- int pid;
+ int pid, ret;
int command[2], response[2];
struct sigaction act = { .sa_handler = do_alarm };
- char name[PATH_MAX];
+ char name[1+PATH_MAX];
if (pipe(command) != 0 || pipe(response) != 0)
- return -1;
+ return NULL;
pid = fork();
if (pid < 0)
- return -1;
+ return NULL;
if (pid != 0) {
+ struct agent *agent = malloc(sizeof(*agent));
+
close(command[0]);
close(response[1]);
- /* FIXME: Make fds consective. */
- dup2(command[1]+1, response[1]);
- return command[1];
+ agent->cmdfd = command[1];
+ agent->responsefd = response[0];
+ return agent;
}
close(command[1]);
close(response[0]);
sigaction(SIGALRM, &act, NULL);
- while (read(command[0], name, sizeof(name)) != 0) {
- int result = do_transaction(name);
+ while ((ret = read(command[0], name, sizeof(name))) > 0) {
+ int result;
+
+ result = do_operation(name[0], name+1);
if (write(response[1], &result, sizeof(result))
!= sizeof(result))
err(1, "Writing response");
}
+ diag("external: read %i: %s", ret, strerror(errno));
exit(0);
}
-/* Ask the external agent to try to do a transaction. */
-bool external_agent_transaction(int handle, const char *tdbname)
+/* Ask the external agent to try to do an operation. */
+int external_agent_operation(struct agent *agent,
+ enum operation op, const char *tdbname)
{
int res;
+ char string[1 + strlen(tdbname) + 1];
+
+ string[0] = op;
+ strcpy(string+1, tdbname);
- if (write(handle, tdbname, strlen(tdbname)+1)
- != strlen(tdbname)+1)
+ if (write(agent->cmdfd, string, sizeof(string)) != sizeof(string))
err(1, "Writing to agent");
- if (read(handle+1, &res, sizeof(res)) != sizeof(res))
+ if (read(agent->responsefd, &res, sizeof(res)) != sizeof(res))
err(1, "Reading from agent");
if (res > 1)
return res;
}
+
+void external_agent_operation_start(struct agent *agent,
+ enum operation op, const char *tdbname)
+{
+ char string[1 + strlen(tdbname) + 1];
+
+ string[0] = op;
+ strcpy(string+1, tdbname);
+
+ if (write(agent->cmdfd, string, sizeof(string)) != sizeof(string))
+ err(1, "Writing to agent");
+}
+
+bool external_agent_operation_check(struct agent *agent, bool block, int *res)
+{
+ int flags = fcntl(agent->responsefd, F_GETFL);
+
+ if (block)
+ fcntl(agent->responsefd, F_SETFL, flags & ~O_NONBLOCK);
+ else
+ fcntl(agent->responsefd, F_SETFL, flags | O_NONBLOCK);
+
+ switch (read(agent->responsefd, res, sizeof(*res))) {
+ case sizeof(*res):
+ break;
+ case 0:
+ errx(1, "Agent died?");
+ default:
+ if (!block && (errno == EAGAIN || errno == EWOULDBLOCK))
+ return false;
+ err(1, "%slocking reading from agent", block ? "B" : "Non-b");
+ }
+
+ if (*res > 1)
+ errx(1, "Agent returned %u\n", *res);
+
+ return true;
+}
projects / ccan / blobdiff