1 /* 2 * An implementation of host to guest copy functionality for Linux. 3 * 4 * Copyright (C) 2014, Microsoft, Inc. 5 * 6 * Author : K. Y. Srinivasan <kys@microsoft.com> 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License version 2 as published 10 * by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, but 13 * WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or 15 * NON INFRINGEMENT. See the GNU General Public License for more 16 * details. 17 */ 18 19 20 #include <sys/types.h> 21 #include <sys/socket.h> 22 #include <sys/poll.h> 23 #include <linux/types.h> 24 #include <linux/kdev_t.h> 25 #include <stdio.h> 26 #include <stdlib.h> 27 #include <unistd.h> 28 #include <string.h> 29 #include <ctype.h> 30 #include <errno.h> 31 #include <linux/hyperv.h> 32 #include <syslog.h> 33 #include <sys/stat.h> 34 #include <fcntl.h> 35 #include <dirent.h> 36 #include <getopt.h> 37 38 static int target_fd; 39 static char target_fname[W_MAX_PATH]; 40 41 static int hv_start_fcopy(struct hv_start_fcopy *smsg) 42 { 43 int error = HV_E_FAIL; 44 char *q, *p; 45 46 p = (char *)smsg->path_name; 47 snprintf(target_fname, sizeof(target_fname), "%s/%s", 48 (char *)smsg->path_name, (char *)smsg->file_name); 49 50 syslog(LOG_INFO, "Target file name: %s", target_fname); 51 /* 52 * Check to see if the path is already in place; if not, 53 * create if required. 54 */ 55 while ((q = strchr(p, '/')) != NULL) { 56 if (q == p) { 57 p++; 58 continue; 59 } 60 *q = '\0'; 61 if (access((char *)smsg->path_name, F_OK)) { 62 if (smsg->copy_flags & CREATE_PATH) { 63 if (mkdir((char *)smsg->path_name, 0755)) { 64 syslog(LOG_ERR, "Failed to create %s", 65 (char *)smsg->path_name); 66 goto done; 67 } 68 } else { 69 syslog(LOG_ERR, "Invalid path: %s", 70 (char *)smsg->path_name); 71 goto done; 72 } 73 } 74 p = q + 1; 75 *q = '/'; 76 } 77 78 if (!access(target_fname, F_OK)) { 79 syslog(LOG_INFO, "File: %s exists", target_fname); 80 if (!(smsg->copy_flags & OVER_WRITE)) { 81 error = HV_ERROR_ALREADY_EXISTS; 82 goto done; 83 } 84 } 85 86 target_fd = open(target_fname, 87 O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0744); 88 if (target_fd == -1) { 89 syslog(LOG_INFO, "Open Failed: %s", strerror(errno)); 90 goto done; 91 } 92 93 error = 0; 94 done: 95 return error; 96 } 97 98 static int hv_copy_data(struct hv_do_fcopy *cpmsg) 99 { 100 ssize_t bytes_written; 101 102 bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size, 103 cpmsg->offset); 104 105 if (bytes_written != cpmsg->size) 106 return HV_E_FAIL; 107 108 return 0; 109 } 110 111 static int hv_copy_finished(void) 112 { 113 close(target_fd); 114 return 0; 115 } 116 static int hv_copy_cancel(void) 117 { 118 close(target_fd); 119 unlink(target_fname); 120 return 0; 121 122 } 123 124 void print_usage(char *argv[]) 125 { 126 fprintf(stderr, "Usage: %s [options]\n" 127 "Options are:\n" 128 " -n, --no-daemon stay in foreground, don't daemonize\n" 129 " -h, --help print this help\n", argv[0]); 130 } 131 132 int main(int argc, char *argv[]) 133 { 134 int fcopy_fd, len; 135 int error; 136 int daemonize = 1, long_index = 0, opt; 137 int version = FCOPY_CURRENT_VERSION; 138 char *buffer[4096 * 2]; 139 struct hv_fcopy_hdr *in_msg; 140 int in_handshake = 1; 141 __u32 kernel_modver; 142 143 static struct option long_options[] = { 144 {"help", no_argument, 0, 'h' }, 145 {"no-daemon", no_argument, 0, 'n' }, 146 {0, 0, 0, 0 } 147 }; 148 149 while ((opt = getopt_long(argc, argv, "hn", long_options, 150 &long_index)) != -1) { 151 switch (opt) { 152 case 'n': 153 daemonize = 0; 154 break; 155 case 'h': 156 default: 157 print_usage(argv); 158 exit(EXIT_FAILURE); 159 } 160 } 161 162 if (daemonize && daemon(1, 0)) { 163 syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno)); 164 exit(EXIT_FAILURE); 165 } 166 167 openlog("HV_FCOPY", 0, LOG_USER); 168 syslog(LOG_INFO, "HV_FCOPY starting; pid is:%d", getpid()); 169 170 fcopy_fd = open("/dev/vmbus/hv_fcopy", O_RDWR); 171 172 if (fcopy_fd < 0) { 173 syslog(LOG_ERR, "open /dev/vmbus/hv_fcopy failed; error: %d %s", 174 errno, strerror(errno)); 175 exit(EXIT_FAILURE); 176 } 177 178 /* 179 * Register with the kernel. 180 */ 181 if ((write(fcopy_fd, &version, sizeof(int))) != sizeof(int)) { 182 syslog(LOG_ERR, "Registration failed: %s", strerror(errno)); 183 exit(EXIT_FAILURE); 184 } 185 186 while (1) { 187 /* 188 * In this loop we process fcopy messages after the 189 * handshake is complete. 190 */ 191 len = pread(fcopy_fd, buffer, (4096 * 2), 0); 192 if (len < 0) { 193 syslog(LOG_ERR, "pread failed: %s", strerror(errno)); 194 exit(EXIT_FAILURE); 195 } 196 197 if (in_handshake) { 198 if (len != sizeof(kernel_modver)) { 199 syslog(LOG_ERR, "invalid version negotiation"); 200 exit(EXIT_FAILURE); 201 } 202 kernel_modver = *(__u32 *)buffer; 203 in_handshake = 0; 204 syslog(LOG_INFO, "HV_FCOPY: kernel module version: %d", 205 kernel_modver); 206 continue; 207 } 208 209 in_msg = (struct hv_fcopy_hdr *)buffer; 210 211 switch (in_msg->operation) { 212 case START_FILE_COPY: 213 error = hv_start_fcopy((struct hv_start_fcopy *)in_msg); 214 break; 215 case WRITE_TO_FILE: 216 error = hv_copy_data((struct hv_do_fcopy *)in_msg); 217 break; 218 case COMPLETE_FCOPY: 219 error = hv_copy_finished(); 220 break; 221 case CANCEL_FCOPY: 222 error = hv_copy_cancel(); 223 break; 224 225 default: 226 syslog(LOG_ERR, "Unknown operation: %d", 227 in_msg->operation); 228 229 } 230 231 if (pwrite(fcopy_fd, &error, sizeof(int), 0) != sizeof(int)) { 232 syslog(LOG_ERR, "pwrite failed: %s", strerror(errno)); 233 exit(EXIT_FAILURE); 234 } 235 } 236 } 237