ioops.c

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