| 1 | /* |
| 2 | * General utility functions for udp tunnel |
| 3 | */ |
| 4 | /* |
| 5 | * Copyright 1996-2013 Ian Jackson <ijackson@chiark.greenend.org.uk> |
| 6 | * Copyright 1998 David Damerell <damerell@chiark.greenend.org.uk> |
| 7 | * Copyright 1999,2003 |
| 8 | * Chancellor Masters and Scholars of the University of Cambridge |
| 9 | * Copyright 2010 Tony Finch <fanf@dotat.at> |
| 10 | * |
| 11 | * This is free software; you can redistribute it and/or modify it |
| 12 | * under the terms of the GNU General Public License as published by |
| 13 | * the Free Software Foundation; either version 3 of the License, or |
| 14 | * (at your option) any later version. |
| 15 | * |
| 16 | * This program is distributed in the hope that it will be useful, but |
| 17 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 19 | * General Public License for more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU General Public License |
| 22 | * along with userv-utils; if not, see http://www.gnu.org/licenses/. |
| 23 | */ |
| 24 | |
| 25 | #include <string.h> |
| 26 | #include <errno.h> |
| 27 | #include <unistd.h> |
| 28 | #include <stdlib.h> |
| 29 | #include <assert.h> |
| 30 | |
| 31 | #include "forwarder.h" |
| 32 | |
| 33 | const char *const *argv; |
| 34 | char programid[SYS_NMLN+sizeof(PROGRAM)+3]; |
| 35 | |
| 36 | void arg_assert_fail(const char *msg) { |
| 37 | fprintf(stderr, PROGRAM ": argument error (!`%s')\n",msg); |
| 38 | exit(12); |
| 39 | } |
| 40 | |
| 41 | void sysfail(const char *msg) { |
| 42 | fprintf(stderr, "%s: fatal system error: %s: %s\n", programid, msg, strerror(errno)); |
| 43 | exit(8); |
| 44 | } |
| 45 | |
| 46 | void fail(const char *msg) { |
| 47 | fprintf(stderr, "%s: fatal error: %s\n", programid, msg); |
| 48 | exit(4); |
| 49 | } |
| 50 | |
| 51 | void sysdiag(const char *msg) { |
| 52 | fprintf(stderr, "%s: system/network error: %s: %s\n", programid, msg, strerror(errno)); |
| 53 | } |
| 54 | |
| 55 | void diag(const char *msg) { |
| 56 | fprintf(stderr, "%s: %s\n", programid, msg); |
| 57 | } |
| 58 | |
| 59 | time_t now(void) { |
| 60 | time_t r; |
| 61 | if (time(&r) == (time_t)-1) sysfail("get time of day"); |
| 62 | return r; |
| 63 | } |
| 64 | |
| 65 | void *xmalloc(size_t sz) { |
| 66 | void *r; |
| 67 | r= malloc(sz); |
| 68 | if (!r) sysfail("allocate memory"); |
| 69 | return r; |
| 70 | } |
| 71 | |
| 72 | void write_must(int fd, const void *p_in, int sz, const char *what) { |
| 73 | const unsigned char *p= p_in; |
| 74 | int r; |
| 75 | |
| 76 | while (sz) { |
| 77 | r= write(fd,p,sz); |
| 78 | if (r<0) { |
| 79 | if (errno == EINTR) continue; |
| 80 | else sysfail(what); |
| 81 | } |
| 82 | assert(r && r <= sz); |
| 83 | p += r; |
| 84 | sz -= r; |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | void read_must(int fd, void *p_in, int sz, const char *what) { |
| 89 | unsigned char *p= p_in; |
| 90 | int r; |
| 91 | |
| 92 | while (sz) { |
| 93 | r= read(fd,p,sz); |
| 94 | if (r<0) { |
| 95 | if (errno == EINTR) continue; |
| 96 | else sysfail(what); |
| 97 | } |
| 98 | if (r==0) fail(what); |
| 99 | assert(r <= sz); |
| 100 | p += r; |
| 101 | sz -= r; |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | const char *getarg_string(void) { |
| 106 | const char *arg; |
| 107 | |
| 108 | arg= *++argv; |
| 109 | arg_assert(arg); |
| 110 | return arg; |
| 111 | } |
| 112 | |
| 113 | unsigned long getarg_ulong(void) { |
| 114 | char *ep; |
| 115 | unsigned long ul; |
| 116 | |
| 117 | ul= strtoul(getarg_string(),&ep,0); |
| 118 | arg_assert(!*ep); |
| 119 | return ul; |
| 120 | } |
| 121 | |
| 122 | void *buf_append(struct buffer *buf, size_t amount) { |
| 123 | void *p; |
| 124 | |
| 125 | p= buf->start + buf->size; |
| 126 | buf->size += amount; |
| 127 | return p; |
| 128 | } |
| 129 | |
| 130 | void *buf_prepend(struct buffer *buf, size_t amount) { |
| 131 | buf->size += amount; |
| 132 | return buf->start -= amount; |
| 133 | } |
| 134 | |
| 135 | void *buf_unappend(struct buffer *buf, size_t amount) { |
| 136 | if (buf->size < amount) return 0; |
| 137 | return buf->start + (buf->size -= amount); |
| 138 | } |
| 139 | |
| 140 | void *buf_unprepend(struct buffer *buf, size_t amount) { |
| 141 | void *p; |
| 142 | |
| 143 | p= buf->start; |
| 144 | buf->start += amount; |
| 145 | buf->size -= amount; |
| 146 | return p; |
| 147 | } |