+++ /dev/null
-/* A very simple AWS-like server, without any authentication. This is meant
- * performance testing in a local environment. The server offers weak
- * guarantees on data durability--data is stored directly to the file system
- * without synchronization, so data might be lost in a crash. This should
- * offer good performance though for benchmarking.
- *
- * Protocol: Each request is a whitespace-separated (typically, a single space)
- * list of parameters terminated by a newline character. The response is a
- * line containing a response code and a body length (again white-separated and
- * newline-terminated) followed by the response body. Requests:
- * GET filename offset length
- * PUT filename length
- * DELETE filename
- * LIST prefix
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <assert.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <string.h>
-#include <time.h>
-#include <unistd.h>
-#include <netinet/in.h>
-#include <sys/socket.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-
-/* Maximum number of connections the server will queue waiting for us to call
- * accept(). */
-#define TCP_BACKLOG 32
-
-#define WHITESPACE " \t\r\n"
-#define MAX_ARGS 4
-
-/* Maximum length of a command that we will accept. */
-#define MAX_CMD_LEN 4096
-
-#define MAX_OBJECT_SIZE (256 << 20)
-
-enum command { GET, PUT, LIST, DELETE };
-
-void write_data(int fd, const char *buf, size_t len)
-{
- while (len > 0) {
- ssize_t bytes = write(fd, buf, len);
- if (bytes < 0) {
- if (errno == EINTR)
- continue;
- exit(1);
- }
- buf += bytes;
- len -= bytes;
- }
-}
-
-/* SIGCHLD handler, used to clean up processes that handle the connections. */
-static void sigchld_handler(int signal)
-{
- int pid;
- int reaped = 0;
-
- while ((pid = waitpid(WAIT_ANY, NULL, WNOHANG)) > 0) {
- reaped++;
- }
-
- if (pid < 0) {
- if (errno == ECHILD && reaped) {
- /* Don't print an error for the caes that we successfully cleaned
- * up after all children. */
- } else {
- perror("waitpid");
- }
- }
-}
-
-/* Return a text representation of a socket address. Returns a pointer to a
- * static buffer so it is non-reentrant. */
-const char *sockname(struct sockaddr_in *addr, socklen_t len)
-{
- static char buf[128];
- if (len < sizeof(struct sockaddr_in))
- return NULL;
- if (addr->sin_family != AF_INET)
- return NULL;
-
- uint32_t ip = ntohl(addr->sin_addr.s_addr);
- sprintf(buf, "%d.%d.%d.%d:%d",
- (int)((ip >> 24) & 0xff),
- (int)((ip >> 16) & 0xff),
- (int)((ip >> 8) & 0xff),
- (int)(ip & 0xff),
- ntohs(addr->sin_port));
-
- return buf;
-}
-
-/* Convert a path from a client to the actual filename used. Returns a string
- * that must be freed. */
-char *normalize_path(const char *in)
-{
- char *out = malloc(2 * strlen(in) + 1);
- int i, j;
- for (i = 0, j = 0; in[i] != '\0'; i++) {
- if (in[i] == '/') {
- out[j++] = '_';
- out[j++] = 's';
- } else if (in[i] == '_') {
- out[j++] = '_';
- out[j++] = 'u';
- } else {
- out[j++] = in[i];
- }
- }
- out[j++] = '\0';
- return out;
-}
-
-void cmd_get(int fd, char *path, size_t start, ssize_t len)
-{
- char buf[65536];
-
- char *response = "-1\n";
- int file = open(path, O_RDONLY);
- if (file < 0) {
- write_data(fd, response, strlen(response));
- return;
- }
-
- struct stat statbuf;
- if (fstat(file, &statbuf) < 0) {
- write_data(fd, response, strlen(response));
- return;
- }
-
- size_t datalen = statbuf.st_size;
- if (start > 0) {
- if (start >= datalen) {
- datalen = 0;
- } else {
- lseek(file, start, SEEK_SET);
- datalen -= start;
- }
- }
- if (len > 0 && len < datalen) {
- datalen = len;
- }
-
- sprintf(buf, "%zd\n", datalen);
- write_data(fd, buf, strlen(buf));
-
- while (datalen > 0) {
- size_t needed = datalen > sizeof(buf) ? sizeof(buf) : datalen;
- ssize_t bytes = read(file, buf, needed);
- if (bytes < 0 && errno == EINTR)
- continue;
- if (bytes <= 0) {
- /* Error reading necessary data, but we already told the client the
- * file size so pad the data to the client with null bytes. */
- memset(buf, 0, needed);
- bytes = needed;
- }
- write_data(fd, buf, bytes);
- datalen -= bytes;
- }
-
- close(file);
-}
-
-void cmd_put(int fd, char *path, char *buf,
- size_t object_size, size_t buf_used)
-{
- while (buf_used < object_size) {
- ssize_t bytes;
-
- bytes = read(fd, buf + buf_used, object_size - buf_used);
- if (bytes < 0) {
- if (errno == EINTR)
- continue;
- else
- exit(1);
- }
-
- if (bytes == 0)
- exit(1);
-
- assert(bytes <= object_size - buf_used);
- buf_used += bytes;
-
- continue;
- }
-
- printf("Got %zd bytes for object '%s'\n", buf_used, path);
-
- char *response = "-1\n";
- int file = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0600);
- if (file >= 0) {
- write_data(file, buf, object_size);
- response = "0\n";
- close(file);
- }
-
- write_data(fd, response, strlen(response));
-}
-
-/* The core handler for processing requests from the client. This can be
- * single-threaded since each connection is handled in a separate process. */
-void handle_connection(int fd)
-{
- char cmdbuf[MAX_CMD_LEN];
- size_t buflen = 0;
-
- while (1) {
- /* Keep reading data until reaching a newline, so that a complete
- * command can be parsed. */
- if (buflen == 0 || memchr(cmdbuf, '\n', buflen) == NULL) {
- ssize_t bytes;
-
- if (buflen == MAX_CMD_LEN) {
- /* Command is too long and thus malformed; close the
- * connection. */
- return;
- }
-
- bytes = read(fd, cmdbuf + buflen, MAX_CMD_LEN - buflen);
- if (bytes < 0) {
- if (errno == EINTR)
- continue;
- else
- return;
- }
- if (bytes == 0)
- return;
-
- assert(bytes <= MAX_CMD_LEN - buflen);
- buflen += bytes;
-
- continue;
- }
-
- size_t cmdlen = (char *)memchr(cmdbuf, '\n', buflen) - cmdbuf + 1;
- cmdbuf[cmdlen - 1] = '\0';
- char *token;
- int arg_count;
- char *args[MAX_ARGS];
- int arg_int[MAX_ARGS];
- for (token = strtok(cmdbuf, WHITESPACE), arg_count = 0;
- token != NULL;
- token = strtok(NULL, WHITESPACE), arg_count++)
- {
- args[arg_count] = token;
- arg_int[arg_count] = atoi(token);
- }
-
- if (arg_count < 2) {
- return;
- }
- char *path = normalize_path(args[1]);
- enum command cmd;
- if (strcmp(args[0], "GET") == 0 && arg_count == 4) {
- cmd = GET;
- } else if (strcmp(args[0], "PUT") == 0 && arg_count == 3) {
- cmd = PUT;
- } else if (strcmp(args[0], "DELETE") == 0 && arg_count == 2) {
- cmd = DELETE;
- } else {
- return;
- }
-
- if (cmdlen < buflen)
- memmove(cmdbuf, cmdbuf + cmdlen, buflen - cmdlen);
- buflen -= cmdlen;
-
- switch (cmd) {
- case GET:
- cmd_get(fd, path, arg_int[2], arg_int[3]);
- break;
- case PUT: {
- size_t object_size = arg_int[2];
- if (object_size > MAX_OBJECT_SIZE)
- return;
- char *data_buf = malloc(object_size);
- if (data_buf == NULL)
- return;
- size_t data_buflen = buflen > object_size ? object_size : buflen;
- if (data_buflen > 0)
- memcpy(data_buf, cmdbuf, data_buflen);
- if (data_buflen < buflen) {
- memmove(cmdbuf, cmdbuf + data_buflen, buflen - data_buflen);
- buflen -= cmdlen;
- } else {
- buflen = 0;
- }
- cmd_put(fd, path, data_buf, object_size, data_buflen);
- break;
- }
- case DELETE:
- //cmd_delete(fd, path);
- break;
- default:
- return;
- }
-
- free(path);
- }
-}
-
-/* Create a listening TCP socket on a new address (we do not use a fixed port).
- * Return the file descriptor of the listening socket. */
-int server_init()
-{
- int fd;
- struct sockaddr_in server_addr;
- socklen_t addr_len = sizeof(server_addr);
-
- fd = socket(PF_INET, SOCK_STREAM, 0);
- if (fd < 0) {
- perror("socket");
- exit(1);
- }
-
- if (listen(fd, TCP_BACKLOG) < 0) {
- perror("listen");
- exit(1);
- }
-
- if (getsockname(fd, (struct sockaddr *)&server_addr, &addr_len) < 0) {
- perror("getsockname");
- exit(1);
- }
-
- printf("Server listening on %s ...\n", sockname(&server_addr, addr_len));
- fflush(stdout);
-
- return fd;
-}
-
-/* Process-based server main loop. Wait for a connection, accept it, fork a
- * child process to handle the connection, and repeat. Child processes are
- * reaped in the SIGCHLD handler. */
-void server_main(int listen_fd)
-{
- struct sigaction handler;
-
- /* Install signal handler for SIGCHLD. */
- handler.sa_handler = sigchld_handler;
- sigemptyset(&handler.sa_mask);
- handler.sa_flags = SA_RESTART;
- if (sigaction(SIGCHLD, &handler, NULL) < 0) {
- perror("sigaction");
- exit(1);
- }
-
- while (1) {
- struct sockaddr_in client_addr;
- socklen_t addr_len = sizeof(client_addr);
- int client_fd = accept(listen_fd, (struct sockaddr *)&client_addr,
- &addr_len);
- int pid;
-
- /* Very simple error handling. Exit if something goes wrong. Later,
- * might want to look into not killing off current connections abruptly
- * if we encounter an error in the accept(). */
- if (client_fd < 0) {
- if (errno == EINTR)
- continue;
-
- perror("accept");
- exit(1);
- }
-
- printf("Accepted connection from %s ...\n",
- sockname(&client_addr, addr_len));
- fflush(stdout);
-
- pid = fork();
- if (pid < 0) {
- perror("fork");
- } else if (pid == 0) {
- handle_connection(client_fd);
- printf("Closing connection %s ...\n",
- sockname(&client_addr, addr_len));
- close(client_fd);
- exit(0);
- }
-
- close(client_fd);
- }
-}
-
-/* Print a help message describing command-line options to stdout. */
-static void usage(char *argv0)
-{
- printf("Usage: %s [options...]\n"
- "A simple key-value storage server.\n", argv0);
-}
-
-int main(int argc, char *argv[])
-{
- int fd;
- //int i;
- int display_help = 0, cmdline_error = 0;
-
-#if 0
- for (i = 1; i < argc; i++) {
- if (strcmp(argv[i], "-help") == 0) {
- display_help = 1;
- } else if (strcmp(argv[i], "-document_root") == 0) {
- i++;
- if (i >= argc) {
- fprintf(stderr,
- "Error: Argument to -document_root expected.\n");
- cmdline_error = 1;
- } else {
- document_root = argv[i];
- }
- } else if (strcmp(argv[i], "-port") == 0) {
- i++;
- if (i >= argc) {
- fprintf(stderr,
- "Error: Expected port number after -port.\n");
- cmdline_error = 1;
- } else {
- server_port = atoi(argv[i]);
- if (server_port < 1 || server_port > 65535) {
- fprintf(stderr,
- "Error: Port must be between 1 and 65535.\n");
- cmdline_error = 1;
- }
- }
- } else if (strcmp(argv[i], "-mime_types") == 0) {
- i++;
- if (i >= argc) {
- fprintf(stderr,
- "Error: Argument to -mime_types expected.\n");
- cmdline_error = 1;
- } else {
- mime_types_file = argv[i];
- }
- } else if (strcmp(argv[i], "-log") == 0) {
- i++;
- if (i >= argc) {
- fprintf(stderr,
- "Error: Argument to -log expected.\n");
- cmdline_error = 1;
- } else {
- log_fname = argv[i];
- }
- } else {
- fprintf(stderr, "Error: Unrecognized option '%s'\n", argv[i]);
- cmdline_error = 1;
- }
- }
-#endif
-
- /* Display a help message if requested, or let the user know to look at the
- * help message if there was an error parsing the command line. In either
- * case, the server never starts. */
- if (display_help) {
- usage(argv[0]);
- exit(0);
- } else if (cmdline_error) {
- fprintf(stderr, "Run '%s -help' for a summary of options.\n", argv[0]);
- exit(2);
- }
-
- fd = server_init();
- if (fd >= 0) {
- server_main(fd);
- }
-
- return 0;
-}
projects / bluesky.git / blobdiff