ioops.c

   1 #ifndef _GNU_SOURCE
   2 # define _GNU_SOURCE
   3 #endif
   4 #include <unistd.h>
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <sys/ioctl.h>
   8 #include <sys/socket.h>
   9 #include <fcntl.h>
  10 #include <linux/if.h>
  11 #include <linux/if_tun.h>
  12
  13 #include "die.h"
  14 #include "dev.h"
  15 #include "ioops.h"
  16 #include "str.h"
  17 #include "built_in.h"
  18
  19 int open_or_die(const char *file, int flags)
  20 {
  21         int ret = open(file, flags);
  22         if (unlikely(ret < 0))
  23                 panic("Cannot open file %s! %s.\n", file, strerror(errno));
  24         return ret;
  25 }
  26
  27 int open_or_die_m(const char *file, int flags, mode_t mode)
  28 {
  29         int ret = open(file, flags, mode);
  30         if (unlikely(ret < 0))
  31                 panic("Cannot open or create file %s! %s.", file, strerror(errno));
  32         return ret;
  33 }
  34
  35 int dup_or_die(int oldfd)
  36 {
  37         int newfd = dup(oldfd);
  38         if (unlikely(newfd < 0))
  39                 panic("Cannot dup old file descriptor!\n");
  40         return newfd;
  41 }
  42
  43 void dup2_or_die(int oldfd, int newfd)
  44 {
  45         int ret = dup2(oldfd, newfd);
  46         if (unlikely(ret < 0))
  47                 panic("Cannot dup2 old/new file descriptor!\n");
  48 }
  49
  50 void create_or_die(const char *file, mode_t mode)
  51 {
  52         int fd = open_or_die_m(file, O_WRONLY | O_CREAT, mode);
  53         close(fd);
  54 }
  55
  56 void pipe_or_die(int pipefd[2], int flags)
  57 {
  58         int ret = pipe2(pipefd, flags);
  59         if (unlikely(ret < 0))
  60                 panic("Cannot create pipe2 event fd! %s.\n", strerror(errno));
  61 }
  62
  63 int tun_open_or_die(const char *name, int type)
  64 {
  65         int fd, ret;
  66         short flags;
  67         struct ifreq ifr;
  68
  69         if (unlikely(!name))
  70                 panic("No name provided for tundev!\n");
  71
  72         fd = open_or_die("/dev/net/tun", O_RDWR);
  73
  74         memset(&ifr, 0, sizeof(ifr));
  75         ifr.ifr_flags = type;
  76         strlcpy(ifr.ifr_name, name, IFNAMSIZ);
  77
  78         ret = ioctl(fd, TUNSETIFF, &ifr);
  79         if (unlikely(ret < 0))
  80                 panic("ioctl screwed up! %s.\n", strerror(errno));
  81
  82         ret = fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
  83         if (unlikely(ret < 0))
  84                 panic("fctnl screwed up! %s.\n", strerror(errno));
  85
  86         flags = device_get_flags(name);
  87         flags |= IFF_UP | IFF_RUNNING;
  88         device_set_flags(name, flags);
  89
  90         return fd;
  91 }
  92
  93 ssize_t read_or_die(int fd, void *buf, size_t len)
  94 {
  95         ssize_t ret = read(fd, buf, len);
  96         if (unlikely(ret < 0)) {
  97                 if (errno == EPIPE)
  98                         die();
  99                 panic("Cannot read from descriptor! %s.\n", strerror(errno));
 100         }
 101
 102         return ret;
 103 }
 104
 105 ssize_t write_or_die(int fd, const void *buf, size_t len)
 106 {
 107         ssize_t ret = write(fd, buf, len);
 108         if (unlikely(ret < 0)) {
 109                 if (errno == EPIPE)
 110                         die();
 111                 panic("Cannot write to descriptor! %s.", strerror(errno));
 112         }
 113
 114         return ret;
 115 }
 116
 117 int read_blob_or_die(const char *file, void *blob, size_t count)
 118 {
 119         int fd, ret;
 120
 121         fd = open_or_die(file, O_RDONLY);
 122         ret = read_or_die(fd, blob, count);
 123         close(fd);
 124
 125         return ret;
 126 }
 127
 128 int write_blob_or_die(const char *file, const void *blob, size_t count)
 129 {
 130         int fd, ret;
 131
 132         fd = open_or_die_m(file, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
 133         ret = write_or_die(fd, blob, count);
 134         fdatasync(fd);
 135         close(fd);
 136
 137         return ret;
 138 }