hdf5/utils/mirror_vfd/mirror_server.c
Dana Robinson 44a00ef876
Strip HD prefix from string/char C API calls (#3540)
* Strip HD prefix from string/char C API calls

* HD(f)(put|get)(s|c)
* HDstr*
* HDv*printf
* HD(s)(print|scan)f
* HDperror

But NOT:

* HDstrcase*
* HDvasprintf
* HDstrtok_r
* HDstrndup

As those are not C99 and have portability work-around
implementations. They will be handled later.

* Fix th5_system.c screwup
2023-09-15 15:13:18 -07:00

642 lines
21 KiB
C

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* 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://www.hdfgroup.org/licenses. *
* 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 LISTENQ 80 /* max pending mirrorS requests */
#define DEFAULT_PORT 3000 /* default listening port */
/* 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 associated 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;
unsigned 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: usage
*
* Purpose: Print the usage message to stdout.
* ---------------------------------------------------------------------------
*/
static void
usage(void)
{
fprintf(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)
{
/* 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 */
memset(args_out->log_path, 0, PATH_MAX + 1);
memset(args_out->writer_log_path, 0, PATH_MAX + 1);
if (argv == NULL || *argv == NULL) {
mirror_log(NULL, V_ERR, "invalid argv pointer");
return -1;
}
/* Loop over arguments after program name */
for (int i = 1; i < argc; i++) {
if (!strncmp(argv[i], "-h", 3) || !strncmp(argv[i], "--help", 7)) {
mirror_log(NULL, V_INFO, "found help argument");
args_out->help = 1;
return 0;
} /* end if help */
else if (!strncmp(argv[i], "--port=", 7)) {
mirror_log(NULL, V_INFO, "parsing 'main_port' (%s)", argv[i] + 7);
args_out->main_port = atoi(argv[i] + 7);
} /* end if port */
else if (!strncmp(argv[i], "--verbosity=", 12)) {
mirror_log(NULL, V_INFO, "parsing 'verbosity' (%s)", argv[i] + 12);
args_out->verbosity = (unsigned int)atoi(argv[i] + 12);
} /* end if verbosity */
else if (!strncmp(argv[i], "--logpath=", 10)) {
mirror_log(NULL, V_INFO, "parsing 'logpath' (%s)", argv[i] + 10);
strncpy(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 = htonl(INADDR_ANY);
server_addr.sin_port = htons((uint16_t)run->opts.main_port);
mirror_log(run->loginfo, V_INFO, "socket()");
ret_value = socket(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()");
setsockopt(ret_value, SOL_SOCKET, SO_REUSEADDR, &_true, sizeof(int));
mirror_log(run->loginfo, V_INFO, "bind()");
ret = bind(ret_value, (struct sockaddr *)&server_addr, sizeof(server_addr));
if (ret < 0) {
mirror_log(run->loginfo, V_ERR, "bind() %s", strerror(errno));
goto error;
}
mirror_log(run->loginfo, V_INFO, "listen()");
ret = listen(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 *)malloc(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) {
free(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)++;
free(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 = accept(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 = gethostbyaddr((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 = inet_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 H5_ATTR_UNUSED sig)
{
while (waitpid(-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 = NULL;
ssize_t ret; /* general-purpose error-checking */
int pid; /* process ID of fork */
struct sigaction sa;
H5FD_mirror_xmit_open_t *xopen = NULL;
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;
}
if (NULL == (mybuf = malloc(H5FD_MIRROR_XMIT_OPEN_SIZE * sizeof(char)))) {
mirror_log(NULL, V_ERR, "out of memory");
goto error;
}
if (NULL == (xopen = malloc(sizeof(H5FD_mirror_xmit_open_t)))) {
mirror_log(NULL, V_ERR, "out of memory");
goto error;
}
/* 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.
*/
if ((ret = HDread(connfd, mybuf, H5FD_MIRROR_XMIT_OPEN_SIZE)) < 0) {
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, (size_t)ret, (const unsigned char *)mybuf);
mirror_log(run->loginfo, V_ALL, "```");
/* Respond to handshake message.
*/
if (!strncmp("SHUTDOWN", mybuf, 8)) {
/* Stop operation if told to stop */
mirror_log(run->loginfo, V_INFO, "received SHUTDOWN!", ret);
/* Confirm operation */
if ((ret = HDwrite(connfd, "CLOSING", 8)) < 0) {
mirror_log(run->loginfo, V_ERR, "write:%d", ret);
HDclose(connfd);
connfd = -1;
goto error;
}
HDclose(connfd);
connfd = -1;
goto done;
} /* end if explicit "SHUTDOWN" directive */
if (!strncmp("CONFIRM", mybuf, 7)) {
/* Confirm operation */
if ((ret = HDwrite(connfd, "ALIVE", 6)) < 0) {
mirror_log(run->loginfo, V_ERR, "write:%d", ret);
goto error;
}
HDclose(connfd);
} /* end if "CONFIRM" directive */
else if (H5FD_MIRROR_XMIT_OPEN_SIZE == ret) {
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 = fork();
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) {
printf("can't run writer\n");
}
else {
printf("writer OK\n");
}
HDclose(connfd);
exit(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);
}
free(mybuf);
free(xopen);
return ret_value;
error:
if (connfd >= 0) {
HDclose(connfd);
}
free(mybuf);
free(xopen);
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");
exit(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");
exit(EXIT_FAILURE);
}
exit(EXIT_SUCCESS);
} /* end main() */
#else /* H5_HAVE_MIRROR_VFD */
int
main(void)
{
printf("Mirror VFD was not built -- cannot launch server.\n");
exit(EXIT_FAILURE);
}
#endif /* H5_HAVE_MIRROR_VFD */