1 | |
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2 | /* |
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3 | * rename_device.c: udev helper to rename ethernet devices. |
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4 | * |
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5 | * Copyright (C) 2006 Red Hat, Inc. All rights reserved. |
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6 | * |
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7 | * This copyrighted material is made available to anyone wishing to use, |
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8 | * modify, copy, or redistribute it subject to the terms and conditions of the |
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9 | * GNU General Public License v.2. |
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10 | * |
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11 | * This program is distributed in the hope that it will be useful, but WITHOUT |
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12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
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14 | * more details. |
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15 | * |
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16 | * You should have received a copy of the GNU General Public License along |
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17 | * with this program; if not, write to the Free Software Foundation, Inc., |
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18 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
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19 | */ |
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20 | |
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21 | |
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22 | #include <dirent.h> |
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23 | #include <errno.h> |
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24 | #include <fcntl.h> |
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25 | #include <signal.h> |
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26 | #include <stdio.h> |
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27 | #include <stdlib.h> |
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28 | #include <string.h> |
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29 | #include <unistd.h> |
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30 | |
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31 | #include <sys/ioctl.h> |
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32 | #include <sys/time.h> |
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33 | #include <sys/types.h> |
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34 | |
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35 | #include <linux/sockios.h> |
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36 | |
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37 | #include <net/if.h> |
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38 | |
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39 | #include <glib.h> |
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40 | |
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41 | #define LOCKFILE "/dev/.rename_device.lock" |
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42 | |
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43 | void sighandler(int dummy) { |
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44 | unlink(LOCKFILE); |
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45 | _exit(1); |
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46 | } |
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47 | |
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48 | struct netdev { |
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49 | char *hwaddr; |
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50 | char *dev; |
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51 | struct netdev *next; |
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52 | }; |
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53 | |
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54 | struct tmp { |
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55 | char *src; |
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56 | char *target; |
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57 | struct tmp *next; |
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58 | }; |
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59 | |
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60 | struct netdev *configs = NULL; |
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61 | struct netdev *devs = NULL; |
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62 | struct tmp *tmplist = NULL; |
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63 | |
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64 | #if defined(__s390__) || defined(__s390x__) |
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65 | static int is_cdev(const struct dirent *dent) { |
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66 | char *end = NULL; |
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67 | |
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68 | if (strncmp(dent->d_name,"cdev",4)) |
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69 | return 0; |
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70 | strtoul(dent->d_name+4,&end, 10); |
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71 | if (*end) |
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72 | return 0; |
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73 | return 1; |
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74 | } |
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75 | |
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76 | static inline char *getdev(char *path, char *ent) { |
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77 | char *a, *b, *ret; |
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78 | |
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79 | asprintf(&a,"%s/%s",path,ent); |
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80 | b = canonicalize_file_name(a); |
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81 | ret = strdup(basename(b)); |
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82 | free(b); |
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83 | free(a); |
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84 | return ret; |
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85 | } |
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86 | |
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87 | char *read_subchannels(char *device) { |
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88 | char *tmp, *path, *ret; |
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89 | int n, x; |
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90 | struct dirent **cdevs; |
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91 | |
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92 | if (asprintf(&path,"/sys/class/net/%s/device",device) == -1) |
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93 | return NULL; |
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94 | if ((n = scandir(path, &cdevs, is_cdev, alphasort)) <= 0) |
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95 | return NULL; |
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96 | |
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97 | ret = getdev(path,cdevs[0]->d_name); |
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98 | for (x = 1 ; x < n ; x++ ) { |
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99 | if (asprintf(&tmp, "%s,%s", ret, getdev(path, cdevs[x]->d_name)) == -1) |
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100 | return NULL; |
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101 | free(ret); |
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102 | ret = tmp; |
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103 | } |
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104 | free(path); |
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105 | return ret; |
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106 | } |
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107 | |
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108 | #endif |
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109 | |
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110 | struct netdev *get_devs() { |
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111 | DIR *dir; |
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112 | struct dirent *entry; |
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113 | struct netdev *ret = NULL, *tmpdev; |
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114 | |
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115 | dir = opendir("/sys/class/net"); |
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116 | if (!dir) |
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117 | return NULL; |
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118 | while ((entry = readdir(dir))) { |
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119 | char *path; |
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120 | gchar *contents; |
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121 | |
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122 | contents = NULL; |
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123 | |
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124 | if (!strcmp(entry->d_name,".") || !strcmp(entry->d_name,"..")) { |
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125 | continue; |
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126 | } |
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127 | if (asprintf(&path,"/sys/class/net/%s/type",entry->d_name) == -1) |
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128 | continue; |
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129 | g_file_get_contents(path, &contents, NULL, NULL); |
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130 | if (!contents) continue; |
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131 | if (atoi(contents) >= 256) { |
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132 | g_free(contents); |
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133 | continue; |
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134 | } |
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135 | g_free(contents); |
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136 | contents = NULL; |
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137 | #if defined(__s390__) || defined(__s390x__) |
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138 | contents = read_subchannels(entry->d_name); |
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139 | #else |
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140 | if (asprintf(&path,"/sys/class/net/%s/address",entry->d_name) == -1) |
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141 | continue; |
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142 | g_file_get_contents(path, &contents, NULL, NULL); |
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143 | #endif /* mainframe */ |
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144 | if (!contents) continue; |
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145 | contents = g_strstrip(contents); |
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146 | tmpdev = calloc(1, sizeof(struct netdev)); |
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147 | tmpdev->dev = g_strstrip(g_strdup(entry->d_name)); |
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148 | tmpdev->hwaddr = g_strstrip(g_strdup(contents)); |
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149 | if (ret) |
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150 | tmpdev->next = ret; |
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151 | ret = tmpdev; |
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152 | g_free(contents); |
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153 | } |
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154 | return ret; |
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155 | } |
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156 | |
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157 | int isCfg(const struct dirent *dent) { |
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158 | int len = strlen(dent->d_name); |
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159 | |
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160 | if (strncmp(dent->d_name,"ifcfg-",6)) |
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161 | return 0; |
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162 | if (strstr(dent->d_name,"rpmnew") || |
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163 | strstr(dent->d_name,"rpmsave") || |
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164 | strstr(dent->d_name,"rpmorig")) |
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165 | return 0; |
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166 | if (dent->d_name[len-1] == '~') |
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167 | return 0; |
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168 | if (!strncmp(dent->d_name+len-4,".bak",4)) |
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169 | return 0; |
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170 | return 1; |
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171 | } |
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172 | |
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173 | static inline char *dequote(char *start, char *end) { |
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174 | if (end==NULL) { |
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175 | end=start; |
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176 | while(*end) end++; |
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177 | } |
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178 | if (end > start) end--; |
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179 | if ((*start == '\'' || *start == '\"') && ( *start == *end ) ) { |
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180 | *end='\0'; |
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181 | if (start<end) start++; |
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182 | } |
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183 | return start; |
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184 | } |
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185 | |
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186 | struct netdev *get_configs() { |
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187 | int ncfgs = 0; |
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188 | struct netdev *ret, *tmpdev; |
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189 | struct dirent **cfgs; |
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190 | int x; |
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191 | |
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192 | ret = NULL; |
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193 | |
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194 | if ((ncfgs = scandir("/etc/sysconfig/network-scripts",&cfgs, |
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195 | isCfg, alphasort)) == -1) { |
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196 | return ret; |
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197 | } |
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198 | for (x = 0; x < ncfgs; x++ ) { |
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199 | char *path; |
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200 | char *devname, *hwaddr; |
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201 | gchar *contents, **lines; |
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202 | int i; |
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203 | |
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204 | devname = hwaddr = contents = NULL; |
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205 | lines = NULL; |
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206 | if (asprintf(&path,"/etc/sysconfig/network-scripts/%s", |
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207 | cfgs[x]->d_name) == -1) |
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208 | continue; |
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209 | g_file_get_contents(path, &contents, NULL, NULL); |
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210 | if (!contents) |
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211 | continue; |
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212 | lines = g_strsplit(contents,"\n", 0); |
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213 | for (i = 0; lines[i]; i++) { |
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214 | if (g_str_has_prefix(lines[i],"DEVICE=")) { |
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215 | devname = lines[i] + 7; |
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216 | /* ignore alias devices */ |
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217 | if (strchr(devname,':')) |
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218 | devname = NULL; |
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219 | } |
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220 | #if defined(__s390__) || defined(__s390x__) |
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221 | if (g_str_has_prefix(lines[i],"SUBCHANNELS=")) { |
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222 | hwaddr = dequote(lines[i] + 12, NULL); |
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223 | } |
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224 | #else |
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225 | if (g_str_has_prefix(lines[i],"HWADDR=")) { |
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226 | hwaddr = dequote(lines[i] + 7, NULL); |
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227 | } |
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228 | #endif |
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229 | } |
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230 | if (!devname || !hwaddr) { |
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231 | g_free(contents); |
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232 | g_strfreev(lines); |
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233 | continue; |
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234 | } |
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235 | tmpdev = calloc(1, sizeof(struct netdev)); |
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236 | tmpdev->dev = g_strstrip(g_strdup(devname)); |
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237 | tmpdev->hwaddr = g_strstrip(g_strdup(hwaddr)); |
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238 | if (ret) |
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239 | tmpdev->next = ret; |
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240 | ret = tmpdev; |
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241 | g_free(contents); |
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242 | g_strfreev(lines); |
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243 | } |
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244 | free(cfgs); |
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245 | return ret; |
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246 | } |
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247 | |
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248 | char *get_hwaddr(char *device) { |
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249 | struct netdev *dev; |
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250 | |
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251 | for (dev = devs; dev; dev = dev->next) |
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252 | if (!strcmp(dev->dev, device)) |
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253 | return dev->hwaddr; |
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254 | return NULL; |
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255 | } |
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256 | |
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257 | char *get_config_by_hwaddr(char *hwaddr, char *current) { |
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258 | struct netdev *config; |
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259 | char *first = NULL; |
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260 | |
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261 | if (!hwaddr) return NULL; |
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262 | |
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263 | for (config = configs; config; config = config->next) { |
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264 | if (strcasecmp(config->hwaddr, hwaddr) != 0) |
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265 | continue; |
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266 | if (!current || !strcasecmp(config->dev, current)) |
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267 | return config->dev; |
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268 | if (!first) |
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269 | first = config->dev; |
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270 | } |
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271 | return first; |
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272 | } |
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273 | |
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274 | char *get_device_by_hwaddr(char *hwaddr) { |
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275 | struct netdev *dev; |
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276 | |
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277 | if (!hwaddr) return NULL; |
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278 | |
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279 | for (dev = devs; dev; dev = dev->next) |
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280 | if (!strcasecmp(dev->hwaddr, hwaddr)) |
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281 | return dev->dev; |
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282 | return NULL; |
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283 | } |
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284 | |
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285 | void take_lock() { |
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286 | int count = 0; |
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287 | int lockfd; |
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288 | |
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289 | while (1) { |
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290 | lockfd = open(LOCKFILE, O_RDWR|O_CREAT|O_EXCL, 0644); |
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291 | if (lockfd != -1) { |
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292 | write(lockfd,"%d\n",getpid()); |
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293 | close(lockfd); |
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294 | break; |
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295 | } |
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296 | count++; |
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297 | /* If we've slept for 20 seconds, break the lock. */ |
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298 | if (count >= 200) { |
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299 | int fd; |
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300 | char buf[32]; |
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301 | int pid; |
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302 | |
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303 | fd = open(LOCKFILE, O_RDONLY); |
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304 | if (fd == -1) |
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305 | break; |
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306 | read(fd,buf,32); |
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307 | close(fd); |
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308 | pid = atoi(buf); |
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309 | if (pid && pid != 1) { |
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310 | kill(pid,SIGKILL); |
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311 | } |
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312 | } |
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313 | usleep(100000); |
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314 | continue; |
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315 | |
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316 | } |
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317 | return; |
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318 | } |
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319 | |
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320 | int main(int argc, char **argv) { |
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321 | char *src, *target, *hw; |
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322 | struct timeval tv; |
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323 | |
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324 | gettimeofday(&tv, NULL); |
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325 | srand(tv.tv_usec); |
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326 | take_lock(); |
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327 | |
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328 | signal(SIGSEGV,sighandler); |
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329 | signal(SIGKILL,sighandler); |
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330 | signal(SIGTERM,sighandler); |
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331 | signal(SIGSEGV,sighandler); |
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332 | signal(SIGALRM,sighandler); |
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333 | alarm(10); |
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334 | |
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335 | configs = get_configs(); |
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336 | devs = get_devs(); |
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337 | |
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338 | src = getenv("INTERFACE"); |
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339 | if (!src) |
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340 | goto out_unlock; |
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341 | hw = get_hwaddr(src); |
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342 | if (!hw) |
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343 | goto out_unlock; |
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344 | target = get_config_by_hwaddr(hw, src); |
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345 | if (!target) |
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346 | goto out_unlock; |
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347 | |
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348 | printf("%s", target); |
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349 | |
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350 | out_unlock: |
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351 | unlink(LOCKFILE); |
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352 | exit(0); |
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353 | } |
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