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Diffstat (limited to '')
| -rw-r--r-- | test/external-agent.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/test/external-agent.c b/test/external-agent.c new file mode 100644 index 0000000..3c59c06 --- /dev/null +++ b/test/external-agent.c @@ -0,0 +1,224 @@ +#include "external-agent.h" +#include "lock-tracking.h" +#include "logging.h" +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> +#include <fcntl.h> +#include <stdlib.h> +#include <limits.h> +#include <string.h> +#include <errno.h> +#include "../common/tdb_private.h" +#include "tap-interface.h" +#include <stdio.h> +#include <stdarg.h> + +static struct tdb_context *tdb; + +static enum agent_return do_operation(enum operation op, const char *name) +{ + TDB_DATA k; + enum agent_return ret; + TDB_DATA data; + + if (op != OPEN && op != OPEN_WITH_CLEAR_IF_FIRST && !tdb) { + diag("external: No tdb open!"); + return OTHER_FAILURE; + } + + k.dptr = discard_const_p(uint8_t, name); + k.dsize = strlen(name); + + locking_would_block = 0; + switch (op) { + case OPEN: + if (tdb) { + diag("Already have tdb %s open", tdb_name(tdb)); + return OTHER_FAILURE; + } + tdb = tdb_open_ex(name, 0, TDB_DEFAULT, O_RDWR, 0, + &taplogctx, NULL); + if (!tdb) { + if (!locking_would_block) + diag("Opening tdb gave %s", strerror(errno)); + ret = OTHER_FAILURE; + } else + ret = SUCCESS; + break; + case OPEN_WITH_CLEAR_IF_FIRST: + if (tdb) + return OTHER_FAILURE; + tdb = tdb_open_ex(name, 0, TDB_CLEAR_IF_FIRST, O_RDWR, 0, + &taplogctx, NULL); + ret = tdb ? SUCCESS : OTHER_FAILURE; + break; + case TRANSACTION_START: + ret = tdb_transaction_start(tdb) == 0 ? SUCCESS : OTHER_FAILURE; + break; + case FETCH: + data = tdb_fetch(tdb, k); + if (data.dptr == NULL) { + if (tdb_error(tdb) == TDB_ERR_NOEXIST) + ret = FAILED; + else + ret = OTHER_FAILURE; + } else if (data.dsize != k.dsize + || memcmp(data.dptr, k.dptr, k.dsize) != 0) { + ret = OTHER_FAILURE; + } else { + ret = SUCCESS; + } + free(data.dptr); + break; + case STORE: + ret = tdb_store(tdb, k, k, 0) == 0 ? SUCCESS : OTHER_FAILURE; + break; + case TRANSACTION_COMMIT: + ret = tdb_transaction_commit(tdb)==0 ? SUCCESS : OTHER_FAILURE; + break; + case CHECK: + ret = tdb_check(tdb, NULL, NULL) == 0 ? SUCCESS : OTHER_FAILURE; + break; + case NEEDS_RECOVERY: + ret = tdb_needs_recovery(tdb) ? SUCCESS : FAILED; + break; + case CLOSE: + ret = tdb_close(tdb) == 0 ? SUCCESS : OTHER_FAILURE; + tdb = NULL; + break; + case PING: + ret = SUCCESS; + break; + case UNMAP: + ret = tdb_munmap(tdb) == 0 ? SUCCESS : OTHER_FAILURE; + if (ret == SUCCESS) { + tdb->flags |= TDB_NOMMAP; + } + break; + default: + ret = OTHER_FAILURE; + } + + if (locking_would_block) + ret = WOULD_HAVE_BLOCKED; + + return ret; +} + +struct agent { + int cmdfd, responsefd; + pid_t pid; +}; + +/* Do this before doing any tdb stuff. Return handle, or NULL. */ +struct agent *prepare_external_agent(void) +{ + int ret; + int command[2], response[2]; + char name[1+PATH_MAX]; + struct agent *agent = malloc(sizeof(*agent)); + + if (pipe(command) != 0 || pipe(response) != 0) { + fprintf(stderr, "pipe failed: %s\n", strerror(errno)); + exit(1); + } + + agent->pid = fork(); + if (agent->pid < 0) { + fprintf(stderr, "fork failed: %s\n", strerror(errno)); + exit(1); + } + + if (agent->pid != 0) { + close(command[0]); + close(response[1]); + agent->cmdfd = command[1]; + agent->responsefd = response[0]; + return agent; + } + + close(command[1]); + close(response[0]); + + /* We want to fail, not block. */ + nonblocking_locks = true; + log_prefix = "external: "; + while ((ret = read(command[0], name, sizeof(name))) > 0) { + enum agent_return result; + + result = do_operation(name[0], name+1); + if (write(response[1], &result, sizeof(result)) + != sizeof(result)) + abort(); + } + exit(0); +} + +void shutdown_agent(struct agent *agent) +{ + pid_t p; + + close(agent->cmdfd); + close(agent->responsefd); + p = waitpid(agent->pid, NULL, WNOHANG); + if (p == 0) { + kill(agent->pid, SIGKILL); + } + waitpid(agent->pid, NULL, 0); + free(agent); +} + +/* Ask the external agent to try to do an operation. */ +enum agent_return external_agent_operation(struct agent *agent, + enum operation op, + const char *name) +{ + enum agent_return res; + unsigned int len; + char *string; + + if (!name) + name = ""; + len = 1 + strlen(name) + 1; + string = malloc(len); + + string[0] = op; + strncpy(string+1, name, len - 1); + string[len-1] = '\0'; + + if (write(agent->cmdfd, string, len) != len + || read(agent->responsefd, &res, sizeof(res)) != sizeof(res)) + res = AGENT_DIED; + + free(string); + return res; +} + +const char *agent_return_name(enum agent_return ret) +{ + return ret == SUCCESS ? "SUCCESS" + : ret == WOULD_HAVE_BLOCKED ? "WOULD_HAVE_BLOCKED" + : ret == AGENT_DIED ? "AGENT_DIED" + : ret == FAILED ? "FAILED" + : ret == OTHER_FAILURE ? "OTHER_FAILURE" + : "**INVALID**"; +} + +const char *operation_name(enum operation op) +{ + switch (op) { + case OPEN: return "OPEN"; + case OPEN_WITH_CLEAR_IF_FIRST: return "OPEN_WITH_CLEAR_IF_FIRST"; + case TRANSACTION_START: return "TRANSACTION_START"; + case FETCH: return "FETCH"; + case STORE: return "STORE"; + case TRANSACTION_COMMIT: return "TRANSACTION_COMMIT"; + case CHECK: return "CHECK"; + case NEEDS_RECOVERY: return "NEEDS_RECOVERY"; + case CLOSE: return "CLOSE"; + case PING: return "PING"; + case UNMAP: return "UNMAP"; + } + return "**INVALID**"; +} |