ioops.c

   1 #ifndef _GNU_SOURCE
   2 # define _GNU_SOURCE
   3 #endif
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include <sys/ioctl.h>
   9 #include <sys/socket.h>
  10 #include <fcntl.h>
  11 #include <linux/if.h>
  12 #include <linux/if_tun.h>
  13
  14 #include "die.h"
  15 #include "dev.h"
  16 #include "ioops.h"
  17 #include "str.h"
  18 #include "built_in.h"
  19
  20 int open_or_die(const char *file, int flags)
  21 {
  22         int ret = open(file, flags);
  23         if (unlikely(ret < 0))
  24                 panic("Cannot open file %s! %s.\n", file, strerror(errno));
  25         return ret;
  26 }
  27
  28 int open_or_die_m(const char *file, int flags, mode_t mode)
  29 {
  30         int ret = open(file, flags, mode);
  31         if (unlikely(ret < 0))
  32                 panic("Cannot open or create file %s! %s.", file, strerror(errno));
  33         return ret;
  34 }
  35
  36 int dup_or_die(int oldfd)
  37 {
  38         int newfd = dup(oldfd);
  39         if (unlikely(newfd < 0))
  40                 panic("Cannot dup old file descriptor!\n");
  41         return newfd;
  42 }
  43
  44 void dup2_or_die(int oldfd, int newfd)
  45 {
  46         int ret = dup2(oldfd, newfd);
  47         if (unlikely(ret < 0))
  48                 panic("Cannot dup2 old/new file descriptor!\n");
  49 }
  50
  51 void create_or_die(const char *file, mode_t mode)
  52 {
  53         int fd = open_or_die_m(file, O_WRONLY | O_CREAT, mode);
  54         close(fd);
  55 }
  56
  57 int mkostemp_or_die(char *templ, int flags)
  58 {
  59         /* mode is 0600 (S_IRUSR | S_IWUSR) by default */
  60         int fd = mkostemp(templ, flags);
  61         if (unlikely(fd < 0))
  62                 panic("Cannot create unique temporary file! %s\n", strerror(errno));
  63         return fd;
  64 }
  65
  66 void pipe_or_die(int pipefd[2], int flags)
  67 {
  68         int ret = pipe2(pipefd, flags);
  69         if (unlikely(ret < 0))
  70                 panic("Cannot create pipe2 event fd! %s.\n", strerror(errno));
  71 }
  72
  73 int tun_open_or_die(const char *name, int type)
  74 {
  75         int fd, ret;
  76         short flags;
  77         struct ifreq ifr;
  78
  79         if (unlikely(!name))
  80                 panic("No name provided for tundev!\n");
  81
  82         fd = open_or_die("/dev/net/tun", O_RDWR);
  83
  84         memset(&ifr, 0, sizeof(ifr));
  85         ifr.ifr_flags = type;
  86         strlcpy(ifr.ifr_name, name, IFNAMSIZ);
  87
  88         ret = ioctl(fd, TUNSETIFF, &ifr);
  89         if (unlikely(ret < 0))
  90                 panic("ioctl screwed up! %s.\n", strerror(errno));
  91
  92         ret = fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
  93         if (unlikely(ret < 0))
  94                 panic("fctnl screwed up! %s.\n", strerror(errno));
  95
  96         flags = device_get_flags(name);
  97         flags |= IFF_UP | IFF_RUNNING;
  98         device_set_flags(name, flags);
  99
 100         return fd;
 101 }
 102
 103 ssize_t read_or_die(int fd, void *buf, size_t len)
 104 {
 105         ssize_t ret = read(fd, buf, len);
 106         if (unlikely(ret < 0)) {
 107                 if (errno == EPIPE)
 108                         die();
 109                 panic("Cannot read from descriptor! %s.\n", strerror(errno));
 110         }
 111
 112         return ret;
 113 }
 114
 115 ssize_t write_or_die(int fd, const void *buf, size_t len)
 116 {
 117         ssize_t ret = write(fd, buf, len);
 118         if (unlikely(ret < 0)) {
 119                 if (errno == EPIPE)
 120                         die();
 121                 panic("Cannot write to descriptor! %s.", strerror(errno));
 122         }
 123
 124         return ret;
 125 }
 126
 127 int read_blob_or_die(const char *file, void *blob, size_t count)
 128 {
 129         int fd, ret;
 130
 131         fd = open_or_die(file, O_RDONLY);
 132         ret = read_or_die(fd, blob, count);
 133         close(fd);
 134
 135         return ret;
 136 }
 137
 138 int write_blob_or_die(const char *file, const void *blob, size_t count)
 139 {
 140         int fd, ret;
 141
 142         fd = open_or_die_m(file, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
 143         ret = write_or_die(fd, blob, count);
 144         fdatasync(fd);
 145         close(fd);
 146
 147         return ret;
 148 }