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