/* * Copyright (c) 1983, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint static const char copyright[] = "@(#) Copyright (c) 1983, 1993\n\ The Regents of the University of California. All rights reserved.\n"; #endif #if 0 #ifndef lint static char sccsid[] = "@(#)main.c 8.1 (Berkeley) 6/6/93"; #endif #endif #include __FBSDID("$FreeBSD$"); /* Many bug fixes are from Jim Guyton */ /* * TFTP User Program -- Command Interface. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "tftp-utils.h" #include "tftp-io.h" #include "tftp-options.h" #include "tftp.h" #define MAXLINE 200 #define TIMEOUT 5 /* secs between rexmt's */ typedef struct sockaddr_storage peeraddr; static int connected; static char mode[32]; static jmp_buf toplevel; volatile int txrx_error; static int peer; #define MAX_MARGV 20 static int margc; static char *margv[MAX_MARGV]; int verbose; static char *port = NULL; static void get(int, char **); static void help(int, char **); static void intr(int); static void modecmd(int, char **); static void put(int, char **); static void quit(int, char **); static void setascii(int, char **); static void setbinary(int, char **); static void setpeer0(char *, const char *); static void setpeer(int, char **); static void settimeoutpacket(int, char **); static void settimeoutnetwork(int, char **); static void setdebug(int, char **); static void setverbose(int, char **); static void showstatus(int, char **); static void setblocksize(int, char **); static void setblocksize2(int, char **); static void setoptions(int, char **); static void setrollover(int, char **); static void setpacketdrop(int, char **); static void command(void) __dead2; static const char *command_prompt(void); static void urihandling(char *URI); static void getusage(char *); static void makeargv(char *line); static void putusage(char *); static void settftpmode(const char *); static char *tail(char *); static struct cmd *getcmd(char *); #define HELPINDENT (sizeof("connect")) struct cmd { const char *name; void (*handler)(int, char **); const char *help; }; static struct cmd cmdtab[] = { { "connect", setpeer, "connect to remote tftp" }, { "mode", modecmd, "set file transfer mode" }, { "put", put, "send file" }, { "get", get, "receive file" }, { "quit", quit, "exit tftp" }, { "verbose", setverbose, "toggle verbose mode" }, { "status", showstatus, "show current status" }, { "binary", setbinary, "set mode to octet" }, { "ascii", setascii, "set mode to netascii" }, { "rexmt", settimeoutpacket, "set per-packet retransmission timeout[-]" }, { "timeout", settimeoutnetwork, "set total retransmission timeout" }, { "trace", setdebug, "enable 'debug packet'[-]" }, { "debug", setdebug, "enable verbose output" }, { "blocksize", setblocksize, "set blocksize[*]" }, { "blocksize2", setblocksize2, "set blocksize as a power of 2[**]" }, { "rollover", setrollover, "rollover after 64K packets[**]" }, { "options", setoptions, "enable or disable RFC2347 style options" }, { "help", help, "print help information" }, { "packetdrop", setpacketdrop, "artificial packetloss feature" }, { "?", help, "print help information" }, { NULL, NULL, NULL } }; static struct modes { const char *m_name; const char *m_mode; } modes[] = { { "ascii", "netascii" }, { "netascii", "netascii" }, { "binary", "octet" }, { "image", "octet" }, { "octet", "octet" }, { NULL, NULL } }; int main(int argc, char *argv[]) { acting_as_client = 1; peer = -1; strcpy(mode, "netascii"); signal(SIGINT, intr); if (argc > 1) { if (setjmp(toplevel) != 0) exit(txrx_error); if (strncmp(argv[1], "tftp://", 7) == 0) { urihandling(argv[1]); exit(txrx_error); } setpeer(argc, argv); } if (setjmp(toplevel) != 0) (void)putchar('\n'); init_options(); command(); } /* * RFC3617 handling of TFTP URIs: * * tftpURI = "tftp://" host "/" file [ mode ] * mode = ";" "mode=" ( "netascii" / "octet" ) * file = *( unreserved / escaped ) * host = * unreserved = * escaped = * * We are cheating a little bit by allowing any mode as specified in the * modes table defined earlier on in this file and mapping it on the real * mode. */ static void urihandling(char *URI) { char uri[ARG_MAX]; char *host = NULL; char *path = NULL; char *opts = NULL; const char *tmode = "octet"; char *s; char line[MAXLINE]; int i; strncpy(uri, URI, ARG_MAX); host = uri + 7; if ((s = strchr(host, '/')) == NULL) { fprintf(stderr, "Invalid URI: Couldn't find / after hostname\n"); exit(1); } *s = '\0'; path = s + 1; if ((s = strchr(path, ';')) != NULL) { *s = '\0'; opts = s + 1; if (strncmp(opts, "mode=", 5) == 0) { tmode = opts; tmode += 5; for (i = 0; modes[i].m_name != NULL; i++) { if (strcmp(modes[i].m_name, tmode) == 0) break; } if (modes[i].m_name == NULL) { fprintf(stderr, "Invalid mode: '%s'\n", mode); exit(1); } settftpmode(modes[i].m_mode); } } else { settftpmode("octet"); } setpeer0(host, NULL); sprintf(line, "get %s", path); makeargv(line); get(margc, margv); } static char hostname[MAXHOSTNAMELEN]; static void setpeer0(char *host, const char *lport) { struct addrinfo hints, *res0, *res; int error; const char *cause = "unknown"; if (connected) { close(peer); peer = -1; } connected = 0; memset(&hints, 0, sizeof(hints)); hints.ai_family = PF_UNSPEC; hints.ai_socktype = SOCK_DGRAM; hints.ai_protocol = IPPROTO_UDP; hints.ai_flags = AI_CANONNAME; if (!lport) lport = "tftp"; error = getaddrinfo(host, lport, &hints, &res0); if (error) { warnx("%s", gai_strerror(error)); return; } for (res = res0; res; res = res->ai_next) { if (res->ai_addrlen > sizeof(peeraddr)) continue; peer = socket(res->ai_family, res->ai_socktype, res->ai_protocol); if (peer < 0) { cause = "socket"; continue; } memset(&peer_sock, 0, sizeof(peer_sock)); peer_sock.ss_family = res->ai_family; peer_sock.ss_len = res->ai_addrlen; if (bind(peer, (struct sockaddr *)&peer_sock, peer_sock.ss_len) < 0) { cause = "bind"; close(peer); peer = -1; continue; } break; } if (peer < 0) warn("%s", cause); else { /* res->ai_addr <= sizeof(peeraddr) is guaranteed */ memcpy(&peer_sock, res->ai_addr, res->ai_addrlen); if (res->ai_canonname) { (void) strncpy(hostname, res->ai_canonname, sizeof(hostname)); } else (void) strncpy(hostname, host, sizeof(hostname)); hostname[sizeof(hostname)-1] = 0; connected = 1; } freeaddrinfo(res0); } static void setpeer(int argc, char *argv[]) { char line[MAXLINE]; if (argc < 2) { strcpy(line, "Connect "); printf("(to) "); fgets(&line[strlen(line)], sizeof line - strlen(line), stdin); makeargv(line); argc = margc; argv = margv; } if ((argc < 2) || (argc > 3)) { printf("usage: %s [host [port]]\n", argv[0]); return; } if (argc == 3) { port = argv[2]; setpeer0(argv[1], argv[2]); } else setpeer0(argv[1], NULL); } static void modecmd(int argc, char *argv[]) { struct modes *p; const char *sep; if (argc < 2) { printf("Using %s mode to transfer files.\n", mode); return; } if (argc == 2) { for (p = modes; p->m_name; p++) if (strcmp(argv[1], p->m_name) == 0) break; if (p->m_name) { settftpmode(p->m_mode); return; } printf("%s: unknown mode\n", argv[1]); /* drop through and print usage message */ } printf("usage: %s [", argv[0]); sep = " "; for (p = modes; p->m_name != NULL; p++) { printf("%s%s", sep, p->m_name); if (*sep == ' ') sep = " | "; } printf(" ]\n"); return; } static void setbinary(int argc __unused, char *argv[] __unused) { settftpmode("octet"); } static void setascii(int argc __unused, char *argv[] __unused) { settftpmode("netascii"); } static void settftpmode(const char *newmode) { strcpy(mode, newmode); if (verbose) printf("mode set to %s\n", mode); } /* * Send file(s). */ static void put(int argc, char *argv[]) { int fd; int n; char *cp, *targ; char line[MAXLINE]; struct stat sb; if (argc < 2) { strcpy(line, "send "); printf("(file) "); fgets(&line[strlen(line)], sizeof line - strlen(line), stdin); makeargv(line); argc = margc; argv = margv; } if (argc < 2) { putusage(argv[0]); return; } targ = argv[argc - 1]; if (strrchr(argv[argc - 1], ':')) { char *lcp; for (n = 1; n < argc - 1; n++) if (strchr(argv[n], ':')) { putusage(argv[0]); return; } lcp = argv[argc - 1]; targ = strrchr(lcp, ':'); *targ++ = 0; if (lcp[0] == '[' && lcp[strlen(lcp) - 1] == ']') { lcp[strlen(lcp) - 1] = '\0'; lcp++; } setpeer0(lcp, NULL); } if (!connected) { printf("No target machine specified.\n"); return; } if (argc < 4) { cp = argc == 2 ? tail(targ) : argv[1]; fd = open(cp, O_RDONLY); if (fd < 0) { warn("%s", cp); return; } stat(cp, &sb); asprintf(&options[OPT_TSIZE].o_request, "%ju", sb.st_size); if (verbose) printf("putting %s to %s:%s [%s]\n", cp, hostname, targ, mode); xmitfile(peer, port, fd, targ, mode); return; } /* this assumes the target is a directory */ /* on a remote unix system. hmmmm. */ cp = strchr(targ, '\0'); *cp++ = '/'; for (n = 1; n < argc - 1; n++) { strcpy(cp, tail(argv[n])); fd = open(argv[n], O_RDONLY); if (fd < 0) { warn("%s", argv[n]); continue; } stat(cp, &sb); asprintf(&options[OPT_TSIZE].o_request, "%ju", sb.st_size); if (verbose) printf("putting %s to %s:%s [%s]\n", argv[n], hostname, targ, mode); xmitfile(peer, port, fd, targ, mode); } } static void putusage(char *s) { printf("usage: %s file [remotename]\n", s); printf(" %s file host:remotename\n", s); printf(" %s file1 file2 ... fileN [[host:]remote-directory]\n", s); } /* * Receive file(s). */ static void get(int argc, char *argv[]) { int fd; int n; char *cp; char *src; char line[MAXLINE]; if (argc < 2) { strcpy(line, "get "); printf("(files) "); fgets(&line[strlen(line)], sizeof line - strlen(line), stdin); makeargv(line); argc = margc; argv = margv; } if (argc < 2) { getusage(argv[0]); return; } if (!connected) { for (n = 1; n < argc ; n++) if (strrchr(argv[n], ':') == 0) { printf("No remote host specified and " "no host given for file '%s'\n", argv[n]); getusage(argv[0]); return; } } for (n = 1; n < argc ; n++) { src = strrchr(argv[n], ':'); if (src == NULL) src = argv[n]; else { char *lcp; *src++ = 0; lcp = argv[n]; if (lcp[0] == '[' && lcp[strlen(lcp) - 1] == ']') { lcp[strlen(lcp) - 1] = '\0'; lcp++; } setpeer0(lcp, NULL); if (!connected) continue; } if (argc < 4) { cp = argc == 3 ? argv[2] : tail(src); fd = creat(cp, 0644); if (fd < 0) { warn("%s", cp); return; } if (verbose) printf("getting from %s:%s to %s [%s]\n", hostname, src, cp, mode); recvfile(peer, port, fd, src, mode); break; } cp = tail(src); /* new .. jdg */ fd = creat(cp, 0644); if (fd < 0) { warn("%s", cp); continue; } if (verbose) printf("getting from %s:%s to %s [%s]\n", hostname, src, cp, mode); recvfile(peer, port, fd, src, mode); } } static void getusage(char *s) { printf("usage: %s file [localname]\n", s); printf(" %s [host:]file [localname]\n", s); printf(" %s [host1:]file1 [host2:]file2 ... [hostN:]fileN\n", s); } static void settimeoutpacket(int argc, char *argv[]) { int t; char line[MAXLINE]; if (argc < 2) { strcpy(line, "Packet timeout "); printf("(value) "); fgets(&line[strlen(line)], sizeof line - strlen(line), stdin); makeargv(line); argc = margc; argv = margv; } if (argc != 2) { printf("usage: %s value\n", argv[0]); return; } t = atoi(argv[1]); if (t < 0) { printf("%s: bad value\n", argv[1]); return; } settimeouts(t, timeoutnetwork, maxtimeouts); } static void settimeoutnetwork(int argc, char *argv[]) { int t; char line[MAXLINE]; if (argc < 2) { strcpy(line, "Network timeout "); printf("(value) "); fgets(&line[strlen(line)], sizeof line - strlen(line), stdin); makeargv(line); argc = margc; argv = margv; } if (argc != 2) { printf("usage: %s value\n", argv[0]); return; } t = atoi(argv[1]); if (t < 0) { printf("%s: bad value\n", argv[1]); return; } settimeouts(timeoutpacket, t, maxtimeouts); } static void showstatus(int argc __unused, char *argv[] __unused) { printf("Remote host: %s\n", connected ? hostname : "none specified yet"); printf("RFC2347 Options support: %s\n", options_rfc_enabled ? "enabled" : "disabled"); printf("Non-RFC defined options support: %s\n", options_extra_enabled ? "enabled" : "disabled"); printf("Mode: %s\n", mode); printf("Verbose: %s\n", verbose ? "on" : "off"); printf("Debug: %s\n", debug_show(debug)); printf("Artificial packetloss: %d in 100 packets\n", packetdroppercentage); printf("Segment size: %d bytes\n", segsize); printf("Network timeout: %d seconds\n", timeoutpacket); printf("Maximum network timeout: %d seconds\n", timeoutnetwork); printf("Maximum timeouts: %d \n", maxtimeouts); } static void intr(int dummy __unused) { signal(SIGALRM, SIG_IGN); alarm(0); longjmp(toplevel, -1); } static char * tail(char *filename) { char *s; while (*filename) { s = strrchr(filename, '/'); if (s == NULL) break; if (s[1]) return (s + 1); *s = '\0'; } return (filename); } static const char * command_prompt(void) { return ("tftp> "); } /* * Command parser. */ static void command(void) { HistEvent he; struct cmd *c; static EditLine *el; static History *hist; const char *bp; char *cp; int len, num, vrbose; char line[MAXLINE]; vrbose = isatty(0); if (vrbose) { el = el_init("tftp", stdin, stdout, stderr); hist = history_init(); history(hist, &he, H_SETSIZE, 100); el_set(el, EL_HIST, history, hist); el_set(el, EL_EDITOR, "emacs"); el_set(el, EL_PROMPT, command_prompt); el_set(el, EL_SIGNAL, 1); el_source(el, NULL); } for (;;) { if (vrbose) { if ((bp = el_gets(el, &num)) == NULL || num == 0) exit(0); len = (num > MAXLINE) ? MAXLINE : num; memcpy(line, bp, len); line[len] = '\0'; history(hist, &he, H_ENTER, bp); } else { line[0] = 0; if (fgets(line, sizeof line , stdin) == NULL) { if (feof(stdin)) { exit(txrx_error); } else { continue; } } } if ((cp = strchr(line, '\n'))) *cp = '\0'; if (line[0] == 0) continue; makeargv(line); if (margc == 0) continue; c = getcmd(margv[0]); if (c == (struct cmd *)-1) { printf("?Ambiguous command\n"); continue; } if (c == 0) { printf("?Invalid command\n"); continue; } (*c->handler)(margc, margv); } } static struct cmd * getcmd(char *name) { const char *p, *q; struct cmd *c, *found; int nmatches, longest; longest = 0; nmatches = 0; found = 0; for (c = cmdtab; (p = c->name) != NULL; c++) { for (q = name; *q == *p++; q++) if (*q == 0) /* exact match? */ return (c); if (!*q) { /* the name was a prefix */ if (q - name > longest) { longest = q - name; nmatches = 1; found = c; } else if (q - name == longest) nmatches++; } } if (nmatches > 1) return ((struct cmd *)-1); return (found); } /* * Slice a string up into argc/argv. */ static void makeargv(char *line) { char *cp; char **argp = margv; margc = 0; if ((cp = strchr(line, '\n')) != NULL) *cp = '\0'; for (cp = line; margc < MAX_MARGV - 1 && *cp != '\0';) { while (isspace(*cp)) cp++; if (*cp == '\0') break; *argp++ = cp; margc += 1; while (*cp != '\0' && !isspace(*cp)) cp++; if (*cp == '\0') break; *cp++ = '\0'; } *argp++ = 0; } static void quit(int argc __unused, char *argv[] __unused) { exit(txrx_error); } /* * Help command. */ static void help(int argc, char *argv[]) { struct cmd *c; if (argc == 1) { printf("Commands may be abbreviated. Commands are:\n\n"); for (c = cmdtab; c->name; c++) printf("%-*s\t%s\n", (int)HELPINDENT, c->name, c->help); printf("\n[-] : You shouldn't use these ones anymore.\n"); printf("[*] : RFC2347 options support required.\n"); printf("[**] : Non-standard RFC2347 option.\n"); return; } while (--argc > 0) { char *arg; arg = *++argv; c = getcmd(arg); if (c == (struct cmd *)-1) printf("?Ambiguous help command: %s\n", arg); else if (c == (struct cmd *)0) printf("?Invalid help command: %s\n", arg); else printf("%s\n", c->help); } } static void setverbose(int argc __unused, char *argv[] __unused) { verbose = !verbose; printf("Verbose mode %s.\n", verbose ? "on" : "off"); } static void setoptions(int argc, char *argv[]) { if (argc == 2) { if (strcasecmp(argv[1], "enable") == 0 || strcasecmp(argv[1], "on") == 0) { options_extra_enabled = 1; options_rfc_enabled = 1; } if (strcasecmp(argv[1], "disable") == 0 || strcasecmp(argv[1], "off") == 0) { options_extra_enabled = 0; options_rfc_enabled = 0; } if (strcasecmp(argv[1], "extra") == 0) options_extra_enabled = !options_extra_enabled; } printf("Support for RFC2347 style options are now %s.\n", options_rfc_enabled ? "enabled" : "disabled"); printf("Support for non-RFC defined options are now %s.\n", options_extra_enabled ? "enabled" : "disabled"); printf("\nThe following options are available:\n" "\toptions on : enable support for RFC2347 style options\n" "\toptions off : disable support for RFC2347 style options\n" "\toptions extra : toggle support for non-RFC defined options\n" ); } static void setrollover(int argc, char *argv[]) { if (argc == 2) { if (strcasecmp(argv[1], "never") == 0 || strcasecmp(argv[1], "none") == 0) { free(options[OPT_ROLLOVER].o_request); options[OPT_ROLLOVER].o_request = NULL; } if (strcasecmp(argv[1], "1") == 0) { free(options[OPT_ROLLOVER].o_request); options[OPT_ROLLOVER].o_request = strdup("1"); } if (strcasecmp(argv[1], "0") == 0) { free(options[OPT_ROLLOVER].o_request); options[OPT_ROLLOVER].o_request = strdup("0"); } } printf("Support for the rollover options is %s.\n", options[OPT_ROLLOVER].o_request != NULL ? "enabled" : "disabled"); if (options[OPT_ROLLOVER].o_request != NULL) printf("Block rollover will be to block %s.\n", options[OPT_ROLLOVER].o_request); printf("\nThe following rollover options are available:\n" "\trollover 0 : rollover to block zero (default)\n" "\trollover 1 : rollover to block one\n" "\trollover never : do not support the rollover option\n" "\trollover none : do not support the rollover option\n" ); } static void setdebug(int argc, char *argv[]) { int i; if (argc != 1) { i = 1; while (i < argc) debug ^= debug_find(argv[i++]); } printf("The following debugging is enabled: %s\n", debug_show(debug)); printf("\nThe following debugs are available:\n"); i = 0; while (debugs[i].name != NULL) { printf("\t%s\t%s\n", debugs[i].name, debugs[i].desc); i++; } } static void setblocksize(int argc, char *argv[]) { if (!options_rfc_enabled) printf("RFC2347 style options are not enabled " "(but proceeding anyway)\n"); if (argc != 1) { int size = atoi(argv[1]); size_t max; u_long maxdgram; max = sizeof(maxdgram); if (sysctlbyname("net.inet.udp.maxdgram", &maxdgram, &max, NULL, 0) < 0) { perror("sysctl: net.inet.udp.maxdgram"); return; } if (size < BLKSIZE_MIN || size > BLKSIZE_MAX) { printf("Blocksize should be between %d and %d bytes.\n", BLKSIZE_MIN, BLKSIZE_MAX); return; } else if (size > (int)maxdgram - 4) { printf("Blocksize can't be bigger than %ld bytes due " "to the net.inet.udp.maxdgram sysctl limitation.\n", maxdgram - 4); asprintf(&options[OPT_BLKSIZE].o_request, "%ld", maxdgram - 4); } else { asprintf(&options[OPT_BLKSIZE].o_request, "%d", size); } } printf("Blocksize is now %s bytes.\n", options[OPT_BLKSIZE].o_request); } static void setblocksize2(int argc, char *argv[]) { if (!options_rfc_enabled || !options_extra_enabled) printf( "RFC2347 style or non-RFC defined options are not enabled " "(but proceeding anyway)\n"); if (argc != 1) { int size = atoi(argv[1]); int i; size_t max; u_long maxdgram; int sizes[] = { 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 0 }; max = sizeof(maxdgram); if (sysctlbyname("net.inet.udp.maxdgram", &maxdgram, &max, NULL, 0) < 0) { perror("sysctl: net.inet.udp.maxdgram"); return; } for (i = 0; sizes[i] != 0; i++) { if (sizes[i] == size) break; } if (sizes[i] == 0) { printf("Blocksize2 should be a power of two between " "8 and 32768.\n"); return; } if (size < BLKSIZE_MIN || size > BLKSIZE_MAX) { printf("Blocksize2 should be between " "%d and %d bytes.\n", BLKSIZE_MIN, BLKSIZE_MAX); return; } else if (size > (int)maxdgram - 4) { printf("Blocksize2 can't be bigger than %ld bytes due " "to the net.inet.udp.maxdgram sysctl limitation.\n", maxdgram - 4); for (i = 0; sizes[i+1] != 0; i++) { if ((int)maxdgram < sizes[i+1]) break; } asprintf(&options[OPT_BLKSIZE2].o_request, "%d", sizes[i]); } else { asprintf(&options[OPT_BLKSIZE2].o_request, "%d", size); } } printf("Blocksize2 is now %s bytes.\n", options[OPT_BLKSIZE2].o_request); } static void setpacketdrop(int argc, char *argv[]) { if (argc != 1) packetdroppercentage = atoi(argv[1]); printf("Randomly %d in 100 packets will be dropped\n", packetdroppercentage); }