diff options
Diffstat (limited to 'utils/mirror_vfd/mirror_server.c')
-rw-r--r-- | utils/mirror_vfd/mirror_server.c | 666 |
1 files changed, 666 insertions, 0 deletions
diff --git a/utils/mirror_vfd/mirror_server.c b/utils/mirror_vfd/mirror_server.c new file mode 100644 index 0000000..2583e60 --- /dev/null +++ b/utils/mirror_vfd/mirror_server.c @@ -0,0 +1,666 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * Copyright by The HDF Group. * + * All rights reserved. * + * * + * This file is part of HDF5. The full HDF5 copyright notice, including * + * terms governing use, modification, and redistribution, is contained in * + * the COPYING file, which can be found at the root of the source code * + * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases. * + * If you do not have access to either file, you may request a copy from * + * help@hdfgroup.org. * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +/* + * "Server" application to associate a Mirror VFD Driver with a Writer. + * + * Server waits on a dedicated port for a Driver to attempt to connect. + * When connection is made, reads a message from the Driver. + * If message is "SHUTDOWN", Server closes connection and terminates. + * Else, if it receives an encoded OPEN xmit (from Driver), the Server forks + * itself; the child becomes a dedicated Writer and maintains connection with + * the Driver instance, and the parent process remains a Server and returns + * to listening for incoming requests. + * Else, the message is not recognized and is ignored. + * + * + * + * mirror_server [args] + * + * Primary server for coordinating mirror VFD connections with the remote + * process. + * + * args: + * --help, -h Print help message and exit. + * --port=N Positive integer for primary listening port. + * --verbosity=N Debugging verbosity + * 0: none + * 1: errors + * 2: details + * 3: all + * --logpath=S File path to direct debugging output, if any. + * Default of none prints output to stdout. + * + */ + +#include "mirror_remote.h" + +#ifdef H5_HAVE_MIRROR_VFD + +#define MAXBUF 2048 /* max buffer length. */ +#define LISTENQ 80 /* max pending mirrorS requests */ +#define DEFAULT_PORT 3000 /* default listening port */ +#define MAX_PORT_LOOPS 20 /* max iteratations through port range */ +#define PORT_LOOP_RETRY_DELAY 1 /* seconds to wait between port scans */ + +/* semi-unique "magic" numbers to sanity-check structure pointers */ +#define OP_ARGS_MAGIC 0xCF074379u +#define SERVER_RUN_MAGIC 0x741B459Au + + +/* --------------------------------------------------------------------------- + * Structure: struct op_args + * + * Purpose: Convenience structure for holding arguments from command-line. + * + * `magic` (uint32_t) + * Semi-unique number to help validate a pointer to this struct type. + * Must be OP_ARGS_MAGIC to be considered valid. + * + * `help` (int) + * Flag that the help argument was present in the command line. + * + * `main_port` (int) + * Flag that the help argument was present in the command line. + * + * `verbosity` (int) + * Number between 0 (none) and 4 (all) that controls how much detail + * the program prints as a course of logging. + * + * `log_prepend_serv` (int) + * Flag that the logging messages should have 'S- ' at the start of each + * line. + * + * `log_prepend_type` (int) + * Flag that the logging messages should have the assocaited verbosity + * level present in the line (e.g., "WARN", "ERROR", or "INFO"). + * + * `log_path` (char *) + * Path string from the command line, giving the absolute path + * for the file for logging output. Can be empty. + * + * `writer_log_path` (char *) + * Path string from the command line, giving the absolute path + * for the file for writer's logging output. Can be empty. + * + * --------------------------------------------------------------------------- + */ +struct op_args { + uint32_t magic; + int help; + int main_port; + int verbosity; + int log_prepend_serv; + int log_prepend_type; + char log_path[PATH_MAX+1]; + char writer_log_path[PATH_MAX+1]; +}; + + +/* --------------------------------------------------------------------------- + * Structure: struct server_run + * + * Purpose: Convenience structure for holding information about a server + * in operation. + * + * `magic` (uint32_t) + * Semi-unique number to help validate a pointer to this struct type. + * Must be SERVER_RUN_MAGIC to be considered valid. + * + * `log_stream` (FILE *) + * File handle where logging output is directed. + * By default, is stdout. + * + * `opts` (struct opt_args) + * Contained structure, holds the server's configuration. + * + * `listenfd` (int) + * File descriptor of the listening socket. + * + * --------------------------------------------------------------------------- + */ +struct server_run { + uint32_t magic; + struct op_args opts; + struct mirror_log_info *loginfo; + int listenfd; +}; + + +/* --------------------------------------------------------------------------- + * Function: mybzero + * + * Purpose: Introduce bzero without neededing it on the system. + * + * Programmer: Jacob Smith + * 2020-03-30 + * --------------------------------------------------------------------------- + */ +static void mybzero(void *dest, size_t size) +{ + size_t i = 0; + char *s = NULL; + HDassert(dest); + s = (char *)dest; + for (i = 0; i < size; i++) { + *(s+i) = 0; + } +} /* end mybzero() */ + + +/* --------------------------------------------------------------------------- + * Function: usage + * + * Purpose: Print the usage message to stdout. + * --------------------------------------------------------------------------- + */ +static void +usage(void) +{ + HDfprintf(stdout, + "mirror_server [options]\n" \ + "\n" \ + "Application for providing Mirror Writer process to " \ + " Mirror VFD on file-open.\n" \ + "Listens on a dedicated socket; forks as a Writer upon receipt" \ + " of a valid OPEN xmit.\n" \ + "\n" \ + "Options:\n" \ + "--help [-h] : Print this help message and quit.\n" \ + "--logpath=PATH : File path for logging output " \ + "(default none, to stdout).\n" \ + "--port=PORT : Primary port (default %d).\n" \ + "--verbosity=NUM : Debug printing level " \ + "0..4, (default %d).\n", + DEFAULT_PORT, + MIRROR_LOG_DEFAULT_VERBOSITY); +} /* end usage() */ + + +/* --------------------------------------------------------------------------- + * Function: parse_args + * + * Purpose: Read command line options and store results in args_out + * structure. Fails in event of unrecognized option. + * + * Return: 0 on success, -1 on failure. + * --------------------------------------------------------------------------- + */ +static int +parse_args(int argc, char **argv, struct op_args *args_out) +{ + int i; + + /* preset default values + */ + args_out->main_port = DEFAULT_PORT; + args_out->help = 0; + args_out->log_prepend_serv = 1; + args_out->log_prepend_type = 1; + args_out->verbosity = MIRROR_LOG_DEFAULT_VERBOSITY; + /* preset empty strings */ + mybzero(args_out->log_path, PATH_MAX+1); + mybzero(args_out->writer_log_path, PATH_MAX+1); + + if (argv == NULL || *argv == NULL) { + mirror_log(NULL, V_ERR, "invalid argv pointer"); + return -1; + } + + /* Loop over arguments after program name and writer_path */ + for (i=2; i < argc; i++) { + if (!HDstrncmp(argv[i], "-h", 3) || !HDstrncmp(argv[i], "--help", 7)) { + mirror_log(NULL, V_INFO, "found help argument"); + args_out->help = 1; + return 0; + } /* end if help */ + else + if (!HDstrncmp(argv[i], "--port=", 7)) { + mirror_log(NULL, V_INFO, "parsing 'main_port' (%s)", argv[i]+7); + args_out->main_port = HDatoi(argv[i]+7); + } /* end if port */ + else + if (!HDstrncmp(argv[i], "--verbosity=", 12)) { + mirror_log(NULL, V_INFO, "parsing 'verbosity' (%s)", argv[i]+12); + args_out->verbosity = HDatoi(argv[i]+12); + } /* end if verbosity */ + else + if (!HDstrncmp(argv[i], "--logpath=", 10)) { + mirror_log(NULL, V_INFO, "parsing 'logpath' (%s)", argv[i]+10); + HDstrncpy(args_out->log_path, argv[i]+10, PATH_MAX); + } /* end if logpath */ + else { + mirror_log(NULL, V_ERR, "unrecognized argument: %s", argv[i]); + return -1; + } /* end if unrecognized argument */ + } /* end for each arg after the path to writer "receiver process" */ + + mirror_log(NULL, V_INFO, "all args parsed"); + + return 0; +} /* end parse_args() */ + + +/* --------------------------------------------------------------------------- + * Function: prepare_listening_socket + * + * Purpose: Configure and open a socket. + * In event of error, attempts to undo its processes. + * + * Return: Success: non-negative (the file descriptor of the socket) + * Failure: -1 + * --------------------------------------------------------------------------- + */ +static int +prepare_listening_socket(struct server_run *run) +{ + struct sockaddr_in server_addr; + int _true = 1; /* needed for setsockopt() */ + int ret_value = -1; + int ret = 0; /* for checking return value of function calls */ + + if (run == NULL || run->magic != SERVER_RUN_MAGIC) { + mirror_log(NULL, V_ERR, "invalid server_run pointer"); + return -1; + } + + mirror_log(run->loginfo, V_INFO, "preparing socket"); + + server_addr.sin_family = AF_INET; + server_addr.sin_addr.s_addr = HDhtonl(INADDR_ANY); + server_addr.sin_port = HDhtons((uint16_t)run->opts.main_port); + + mirror_log(run->loginfo, V_INFO, "socket()"); + ret_value = HDsocket(AF_INET, SOCK_STREAM, 0); + if (ret_value < 0) { + mirror_log(run->loginfo, V_ERR, "listening socket:%d", ret_value); + goto error; + } + + mirror_log(run->loginfo, V_ALL, "setsockopt()"); + HDsetsockopt(ret_value, SOL_SOCKET, SO_REUSEADDR, &_true, sizeof(int)); + + mirror_log(run->loginfo, V_INFO, "bind()"); + ret = HDbind(ret_value, (struct sockaddr *)&server_addr, + sizeof(server_addr)); + if (ret < 0) { + mirror_log(run->loginfo, V_ERR, "bind() %s", HDstrerror(errno)); + goto error; + } + + mirror_log(run->loginfo, V_INFO, "listen()"); + ret = HDlisten(ret_value, LISTENQ); + if (ret < 0) { + mirror_log(run->loginfo, V_ERR, "H5FD server listen:%d", ret); + goto error; + } + + return ret_value; + +error: + if (ret_value >= 0) { + HDshutdown(ret_value, SHUT_RDWR); + HDclose(ret_value); + } + return -1; +} /* end prepare_listening_socket() */ + + +/* --------------------------------------------------------------------------- + * Function: init_server_run + * + * Purpose: Set up server_run struct with default and specified values. + * + * Return: Zero (0) if successful, -1 if an error occurred. + * --------------------------------------------------------------------------- + */ +static struct server_run * +init_server_run(int argc, char **argv) +{ + struct server_run *run; + + run = (struct server_run *)HDmalloc(sizeof(struct server_run)); + if (run == NULL) { + mirror_log(NULL, V_ERR, "can't allocate server_run struct"); + return NULL; + } + + run->magic = (uint32_t)SERVER_RUN_MAGIC; + run->opts.magic = (uint32_t)OP_ARGS_MAGIC; + run->listenfd = -1; + + if (parse_args(argc, argv, &(run->opts)) < 0) { + mirror_log(NULL, V_ERR, "can't parse arguments"); + usage(); + goto error; + } + + if (run->opts.help) { + usage(); + return run; /* early exit */ + } + + run->loginfo = mirror_log_init(run->opts.log_path, "s- ", + run->opts.verbosity); + + run->listenfd = prepare_listening_socket(run); + if (run->listenfd < 0) { + mirror_log(NULL, V_ERR, "can't prepare listening socket"); + goto error; + } + + return run; + +error: + if (run != NULL) { + HDfree(run); + } + return NULL; + +} /* end init_server_run() */ + + +/* --------------------------------------------------------------------------- + * Function: term_server_run + * + * Purpose: Close opened items in a sever_run and release the pointer. + * + * Return: Zero (0) if successful, -1 if an error occurred. + * --------------------------------------------------------------------------- + */ +static int +term_server_run(struct server_run *run) +{ + if (run == NULL || run->magic != SERVER_RUN_MAGIC) { + mirror_log(NULL, V_ERR, "invalid server_run pointer"); + return -1; + } + + mirror_log(run->loginfo, V_INFO, "shutting down"); + + if (run->listenfd >= 0) { + HDshutdown(run->listenfd, SHUT_RDWR); /* TODO: error-checking? */ + HDclose(run->listenfd); /* TODO: error-checking? */ + run->listenfd = -1; + } + + if (mirror_log_term(run->loginfo) < 0) { + mirror_log(NULL, V_ERR, "can't close logging stream"); + return -1; /* doesn't solve the problem, but informs of error */ + } + run->loginfo = NULL; + + (run->magic)++; + (run->opts.magic)++; + HDfree(run); + return 0; +} /* end term_server_run() */ + + +/* --------------------------------------------------------------------------- + * Function: accept_connection + * + * Purpose: Main working loop; process requests as they are received. + * Does nothing if the run option help is set. + * + * Return: -1 on error, else a non-negative file descriptor of the socket. + * --------------------------------------------------------------------------- + */ +static int +accept_connection(struct server_run *run) +{ + struct sockaddr_in client_addr; /**/ + socklen_t clilen; /**/ + struct hostent *host_port = NULL; /**/ + char *hostaddrp; /**/ + int connfd = -1; /* connection file descriptor */ + + if (run == NULL || run->magic != SERVER_RUN_MAGIC) { + mirror_log(NULL, V_ERR, "invalid server_run pointer"); + return -1; + } + + /*------------------------------*/ + /* accept a connection on a socket */ + clilen = sizeof(client_addr); + connfd = HDaccept(run->listenfd, (struct sockaddr *)&client_addr, &clilen); + if (connfd < 0) { + mirror_log(run->loginfo, V_ERR, "accept:%d", connfd); + goto error; + } + mirror_log(run->loginfo, V_INFO, "connection achieved"); + + /*------------------------------*/ + /* get client address information */ + host_port = HDgethostbyaddr( + (const char *)&client_addr.sin_addr.s_addr, + sizeof(client_addr.sin_addr.s_addr), + AF_INET); + if (host_port == NULL) { + mirror_log(run->loginfo, V_ERR, "gethostbyaddr()"); + goto error; + } + + /* function has the string space statically scoped -- OK until next call */ + hostaddrp = HDinet_ntoa(client_addr.sin_addr); + /* TODO? proper error-checking */ + + mirror_log(run->loginfo, V_INFO, + "server connected with %s (%s)", + host_port->h_name, + hostaddrp); + + return connfd; + +error: + if (connfd >= 0) { + close(connfd); + } + return -1; +} /* end accept_connection() */ + + +/* --------------------------------------------------------------------------- + * Function: wait_for_child + * + * Purpose: Signal handler to reap zombie processes. + * --------------------------------------------------------------------------- + */ +static void +wait_for_child(int sig) +{ + while (HDwaitpid(-1, NULL, WNOHANG) > 0); +} /* end wait_for_child() */ + + +/* --------------------------------------------------------------------------- + * Function: handle_requests + * + * Purpose: Main working loop; process requests as they are received. + * Does nothing if the run option `help` is set. + * + * Return: -1 on error, else 0 for successful operation. + * --------------------------------------------------------------------------- + */ +static int +handle_requests(struct server_run *run) +{ + int connfd = -1; /**/ + char mybuf[H5FD_MIRROR_XMIT_OPEN_SIZE]; /**/ + int ret; /* general-purpose error-checking */ + int pid; /* process ID of fork */ + struct sigaction sa; + int ret_value = 0; + + if (run == NULL || run->magic != SERVER_RUN_MAGIC) { + mirror_log(NULL, V_ERR, "invalid server_run pointer"); + return -1; + } + + if (run->opts.help) { + return 0; + } + + if (run->listenfd < 0) { + mirror_log(NULL, V_ERR, "invalid listening socket"); + return -1; + } + + /* Set up the signal handler */ + sa.sa_handler = wait_for_child; + HDsigemptyset(&sa.sa_mask); + sa.sa_flags = SA_RESTART; + if (HDsigaction(SIGCHLD, &sa, NULL) == -1) { + perror("sigaction"); + return 1; + } + + /* Keep listening for attempts to connect. + */ + + while (1) { /* infinite loop, exited via break or goto */ + mirror_log(run->loginfo, V_INFO, "server waiting for connections..."); + + connfd = -1; + + connfd = accept_connection(run); + if (connfd < 0) { + mirror_log(run->loginfo, V_ERR, "unable to receive connection"); + goto error; + } + + /* Read handshake from port connection. + */ + + ret = (int)HDread(connfd, &mybuf, H5FD_MIRROR_XMIT_OPEN_SIZE); + if (-1 == ret) { + mirror_log(run->loginfo, V_ERR, "read:%d", ret); + goto error; + } + mirror_log(run->loginfo, V_INFO, "received %d bytes", ret); + mirror_log(run->loginfo, V_ALL, "```"); + mirror_log_bytes(run->loginfo, V_ALL, ret, + (const unsigned char *)mybuf); + mirror_log(run->loginfo, V_ALL, "```"); + + /* Respond to handshake message. + */ + + if (!HDstrncmp("SHUTDOWN", mybuf, 8)) { + /* Stop operation if told to stop */ + mirror_log(run->loginfo, V_INFO, "received SHUTDOWN!", ret); + HDclose(connfd); + connfd = -1; + goto done; + } /* end if explicit "SHUTDOWN" directive */ + else + if (H5FD_MIRROR_XMIT_OPEN_SIZE == ret) { + H5FD_mirror_xmit_open_t xopen; + + mirror_log(run->loginfo, V_INFO, + "probable OPEN xmit received"); + + H5FD_mirror_xmit_decode_open(&xopen, (const unsigned char *)mybuf); + if (FALSE == H5FD_mirror_xmit_is_open(&xopen)) { + mirror_log(run->loginfo, V_WARN, + "expected OPEN xmit was malformed"); + HDclose(connfd); + continue; + } + + mirror_log(run->loginfo, V_INFO, + "probable OPEN xmit confirmed"); + + pid = HDfork(); + if (pid < 0) { /* fork error */ + mirror_log(run->loginfo, V_ERR, "cannot fork"); + goto error; + } /* end if fork error */ + else + if (pid == 0) { /* child process (writer side of fork) */ + mirror_log(run->loginfo, V_INFO, + "executing writer"); + if (run_writer(connfd, &xopen) < 0) { + HDprintf("can't run writer\n"); + } + else { + HDprintf("writer OK\n"); + } + HDclose(connfd); + + HDexit(EXIT_SUCCESS); + } /* end if writer side of fork */ + else { /* parent process (server side of fork) */ + mirror_log(run->loginfo, V_INFO, "tidying up from handshake"); + HDclose(connfd); + } /* end if server side of fork */ + + } /* end else-if valid request for service */ + else { + /* Ignore unrecognized messages */ + HDclose(connfd); + continue; + } /* end else (not a valid message, to be ignored) */ + + } /* end while listening for new connections */ + +done: + if (connfd >= 0) { + mirror_log(run->loginfo, V_WARN, "connfd still open upon cleanup"); + HDclose(connfd); + } + + return ret_value; + +error: + if (connfd >= 0) { + HDclose(connfd); + } + return -1; +} /* end handle_requests() */ + + +/* ------------------------------------------------------------------------- */ +int +main(int argc, char **argv) +{ + struct server_run *run; + + run = init_server_run(argc, argv); + if (NULL == run) { + mirror_log(NULL, V_ERR, "can't initialize run"); + HDexit(EXIT_FAILURE); + } + + if (handle_requests(run) < 0) { + mirror_log(run->loginfo, V_ERR, "problem handling requests"); + } + + if (term_server_run(run) < 0) { + mirror_log(NULL, V_ERR, "problem closing server run"); + HDexit(EXIT_FAILURE); + } + + HDexit(EXIT_SUCCESS); +} /* end main() */ + +#else /* H5_HAVE_MIRROR_VFD */ + +int +main(int argc, char **argv) +{ + HDprintf("Mirror VFD was not built -- cannot launch server.\n"); + HDexit(EXIT_FAILURE); +} + +#endif /* H5_HAVE_MIRROR_VFD */ + |