1 | /* |
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2 | Description: Wrapper around DHCP client to restart it when the interface |
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3 | moves to another network. |
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4 | |
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5 | Authors: Arnout Vandecappelle <arnout@mind.be>, Essensium/Mind |
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6 | Maarten Van Es <maarten@mind.be>, Essensium/Mind |
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7 | (C) Septentrio 2008 |
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8 | |
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9 | The license and distribution terms for this file may be |
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10 | found in the file LICENSE in this distribution or at |
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11 | http://www.rtems.org/license/LICENSE. |
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12 | |
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13 | |
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14 | To use this functionality, call rtems_bsdnet_do_dhcp_failsafe() or set it |
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15 | as the bootp member of the rtems_bsdnet_config structure. |
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16 | |
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17 | The rtems_bsdnet_do_dhcp_failsafe() function provides the following |
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18 | functionalities: |
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19 | |
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20 | * It starts DHCP on the first non-loopback, non-point-to-point interface. |
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21 | Before DHCP is started, any existing IP address on that interface is |
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22 | removed, as well as the default route. |
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23 | |
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24 | * If DHCP fails to acquire an address for whatever reason, the interface |
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25 | is reconfigured with the static address provided in its |
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26 | rtems_bsdnet_ifconfig structure, and the default route from |
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27 | rtems_bsdnet_config is restored. |
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28 | It is possible to change the address in the rtems_bsdnet_ifconfig structure |
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29 | while the system is running. |
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30 | |
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31 | * Optionally, after the interface is configured (either with DHCP or |
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32 | statically), a task is started to monitor it. When the interface remains |
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33 | disconnected (i.e. its IFF_RUNNING flag is off) for network_fail_timeout |
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34 | seconds, the dhcp lease renewal is stopped. As soon as the interface is |
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35 | connected again, DHCP is started again as above. |
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36 | If network_fail_timeout is set to 0, the monitor task is not started. |
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37 | |
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38 | * Optionally, when the interface is disconnected, it is also brought down |
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39 | for network_down_time seconds. Since this possibly makes the IFF_RUNNING |
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40 | flag unuseable, the interface is brought up again before the flag is |
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41 | polled. |
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42 | If network_down_time is set to 0, the interface is not brought down. |
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43 | |
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44 | * Optionally, before DHCP is started, we wait for broadcast_delay seconds. |
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45 | This is necessary to allow some routers to perform spanning tree discovery. |
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46 | |
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47 | Note that DHCP doesn't work well with multiple interfaces: only one of them |
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48 | is configured using DHCP, and we can't guarantee it's the same one that is |
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49 | monitored by this function. |
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50 | |
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51 | */ |
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52 | |
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53 | #include <rtems.h> |
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54 | #include <rtems/error.h> |
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55 | #include <rtems/rtems_bsdnet.h> |
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56 | #include <rtems/rtems_bsdnet_internal.h> |
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57 | |
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58 | #include <string.h> |
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59 | #include <stdio.h> |
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60 | #include <errno.h> |
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61 | |
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62 | #include <rtems/dhcp.h> |
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63 | #include <rtems/rtems_dhcp_failsafe.h> |
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64 | |
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65 | struct proc; /* Unused parameter of some functions. */ |
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66 | #include <sys/ioctl.h> |
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67 | #include <sys/socket.h> |
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68 | #include <net/route.h> |
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69 | #include <netinet/in.h> /* for sockaddr_in */ |
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70 | #include <net/if.h> /* for if.h */ |
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71 | #include <net/if_var.h> /* for in_var.h */ |
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72 | #include <netinet/in_var.h> /* for in_aliasreq */ |
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73 | #include <sys/sockio.h> /* for ioctl definitions */ |
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74 | #include <arpa/inet.h> /* for inet_addr, inet_ntop */ |
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75 | |
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76 | |
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77 | static int network_fail_timeout = RTEMS_DHCP_FAILSAFE_NETWORK_FAIL_TIMEOUT; |
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78 | static int network_down_time = RTEMS_DHCP_FAILSAFE_NETWORK_DOWN_TIME; |
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79 | static int broadcast_delay = RTEMS_DHCP_FAILSAFE_BROADCAST_DELAY; |
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80 | static int dhcp_monitor_priority = RTEMS_DHCP_FAILSAFE_DHCP_MONITOR_PRIORITY; |
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81 | |
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82 | void rtems_bsdnet_dhcp_failsafe_config( |
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83 | int network_fail_timeout_, |
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84 | int network_down_time_, |
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85 | int broadcast_delay_, |
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86 | int dhcp_monitor_priority_ |
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87 | ) |
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88 | { |
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89 | network_fail_timeout = network_fail_timeout_; |
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90 | network_down_time = network_down_time_; |
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91 | broadcast_delay = broadcast_delay_; |
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92 | dhcp_monitor_priority = dhcp_monitor_priority_; |
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93 | } |
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94 | |
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95 | /* |
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96 | * returns 0 when successful, negative value for failure |
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97 | */ |
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98 | static int remove_address(const char *if_name) |
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99 | { |
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100 | struct sockaddr_in address; |
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101 | struct in_aliasreq ifra; |
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102 | int retval = 0; |
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103 | |
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104 | memset (&address, '\0', sizeof (address)); |
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105 | address.sin_len = sizeof (address); |
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106 | address.sin_family = AF_INET; |
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107 | address.sin_addr.s_addr = INADDR_ANY; |
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108 | |
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109 | /* Remove old default route to 0.0.0.0 */ |
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110 | if (rtems_bsdnet_rtrequest (RTM_DELETE, (struct sockaddr *)&address, NULL, |
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111 | (struct sockaddr *)&address, |
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112 | (RTF_UP | RTF_STATIC), NULL) < 0 ) { |
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113 | printf ("Failed to delete default route: %s (%d)\n", strerror (errno), errno); |
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114 | retval = -1; |
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115 | } |
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116 | |
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117 | /* Remove old ip-address */ |
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118 | if (rtems_bsdnet_ifconfig(if_name, SIOCGIFADDR, &address) < 0) { |
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119 | printf ("Failed to get if address: %s (%d)\n", strerror (errno), errno); |
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120 | return -1; |
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121 | } |
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122 | |
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123 | strncpy (ifra.ifra_name, if_name, IFNAMSIZ); |
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124 | memcpy (&ifra.ifra_addr, &address, sizeof(address)); |
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125 | if (rtems_bsdnet_ifconfig(if_name, SIOCDIFADDR, &ifra)) { |
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126 | printf ("Can't delete if address: %s (%d)\n", strerror (errno), errno); |
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127 | return -1; |
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128 | } |
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129 | |
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130 | return retval; |
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131 | } |
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132 | |
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133 | |
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134 | static int |
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135 | dhcp_if_down (const char* ifname) |
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136 | { |
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137 | int16_t flags; |
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138 | if (rtems_bsdnet_ifconfig (ifname, SIOCGIFFLAGS, &flags) < 0) { |
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139 | printf ("Can't get flags for %s: %s\n", ifname, strerror (errno)); |
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140 | return -1; |
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141 | } |
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142 | if (flags & IFF_UP) { |
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143 | flags &= ~IFF_UP; |
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144 | if (rtems_bsdnet_ifconfig (ifname, SIOCSIFFLAGS, &flags) < 0) { |
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145 | printf ("Can't bring %s down: %s\n", ifname, strerror (errno)); |
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146 | return -1; |
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147 | } |
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148 | } |
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149 | |
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150 | return 0; |
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151 | } |
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152 | |
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153 | static int |
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154 | dhcp_if_up (const char* ifname) |
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155 | { |
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156 | int16_t flags; |
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157 | if (rtems_bsdnet_ifconfig (ifname, SIOCGIFFLAGS, &flags) < 0) { |
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158 | printf ("Can't get flags for %s: %s\n", ifname, strerror (errno)); |
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159 | return -1; |
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160 | } |
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161 | if (!(flags & IFF_UP)) { |
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162 | flags |= IFF_UP; |
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163 | if (rtems_bsdnet_ifconfig (ifname, SIOCSIFFLAGS, &flags) < 0) { |
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164 | printf ("Can't bring %s up: %s\n", ifname, strerror (errno)); |
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165 | return -1; |
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166 | } |
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167 | } |
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168 | |
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169 | return 0; |
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170 | } |
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171 | |
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172 | |
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173 | static int |
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174 | set_static_address (struct rtems_bsdnet_ifconfig *ifp) |
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175 | { |
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176 | int16_t flags; |
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177 | struct sockaddr_in address; |
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178 | struct sockaddr_in netmask; |
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179 | struct sockaddr_in broadcast; |
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180 | struct sockaddr_in gateway; |
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181 | |
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182 | if (ifp->ip_address != NULL) { |
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183 | printf("Setting static address for interface %s.\n", ifp->name); |
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184 | |
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185 | /* |
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186 | * Bring interface up |
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187 | */ |
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188 | if (dhcp_if_up (ifp->name) < 0) |
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189 | return -1; |
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190 | |
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191 | /* |
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192 | * Set interface netmask |
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193 | */ |
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194 | memset (&netmask, '\0', sizeof netmask); |
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195 | netmask.sin_len = sizeof netmask; |
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196 | netmask.sin_family = AF_INET; |
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197 | netmask.sin_addr.s_addr = inet_addr (ifp->ip_netmask); |
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198 | if (rtems_bsdnet_ifconfig (ifp->name, SIOCSIFNETMASK, &netmask) < 0) { |
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199 | printf ("Can't set %s netmask: %s\n", ifp->name, strerror (errno)); |
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200 | return -1; |
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201 | } |
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202 | |
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203 | /* |
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204 | * Set interface address |
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205 | */ |
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206 | memset (&address, '\0', sizeof address); |
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207 | address.sin_len = sizeof address; |
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208 | address.sin_family = AF_INET; |
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209 | address.sin_addr.s_addr = inet_addr (ifp->ip_address); |
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210 | if (rtems_bsdnet_ifconfig (ifp->name, SIOCSIFADDR, &address) < 0) { |
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211 | printf ("Can't set %s address: %s\n", ifp->name, strerror (errno)); |
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212 | return -1; |
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213 | } |
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214 | |
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215 | /* |
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216 | * Set interface broadcast address if the interface has the |
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217 | * broadcast flag set. |
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218 | */ |
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219 | if (rtems_bsdnet_ifconfig (ifp->name, SIOCGIFFLAGS, &flags) < 0) { |
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220 | printf ("Can't read %s flags: %s\n", ifp->name, strerror (errno)); |
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221 | return -1; |
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222 | } |
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223 | if (flags & IFF_BROADCAST) { |
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224 | memset (&broadcast, '\0', sizeof broadcast); |
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225 | broadcast.sin_len = sizeof broadcast; |
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226 | broadcast.sin_family = AF_INET; |
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227 | broadcast.sin_addr.s_addr = address.sin_addr.s_addr | ~netmask.sin_addr.s_addr; |
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228 | |
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229 | if (rtems_bsdnet_ifconfig (ifp->name, SIOCSIFBRDADDR, &broadcast) < 0) { |
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230 | struct in_addr in_addr; |
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231 | char buf[20]; |
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232 | |
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233 | in_addr.s_addr = broadcast.sin_addr.s_addr; |
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234 | if (!inet_ntop (AF_INET, &in_addr, buf, sizeof (buf))) |
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235 | strcpy (buf, "?.?.?.?"); |
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236 | printf ("Can't set %s broadcast address %s: %s\n", ifp->name, buf, strerror (errno)); |
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237 | } |
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238 | } |
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239 | } |
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240 | |
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241 | /* |
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242 | * Set default route |
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243 | */ |
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244 | if (rtems_bsdnet_config.gateway) { |
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245 | address.sin_addr.s_addr = INADDR_ANY; |
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246 | netmask.sin_addr.s_addr = INADDR_ANY; |
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247 | memset (&gateway, '\0', sizeof gateway); |
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248 | gateway.sin_len = sizeof gateway; |
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249 | gateway.sin_family = AF_INET; |
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250 | gateway.sin_addr.s_addr = inet_addr (rtems_bsdnet_config.gateway); |
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251 | |
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252 | if (rtems_bsdnet_rtrequest (RTM_ADD, |
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253 | (struct sockaddr *) &address, |
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254 | (struct sockaddr *) &gateway, |
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255 | (struct sockaddr *) &netmask, |
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256 | (RTF_UP | RTF_GATEWAY | RTF_STATIC), |
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257 | NULL |
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258 | ) < 0) { |
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259 | printf ("Can't set default route: %s\n", strerror (errno)); |
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260 | return -1; |
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261 | } |
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262 | } |
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263 | |
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264 | return 0; |
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265 | } |
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266 | |
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267 | static void |
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268 | do_dhcp_init (struct rtems_bsdnet_ifconfig *ifp) |
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269 | { |
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270 | if (broadcast_delay) { |
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271 | /* Wait before sending broadcast. */ |
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272 | rtems_task_wake_after(RTEMS_MILLISECONDS_TO_TICKS(broadcast_delay * 1000)); |
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273 | } |
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274 | |
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275 | printf ("starting dhcp client...\n"); |
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276 | |
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277 | remove_address(ifp->name); |
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278 | if (rtems_bsdnet_do_dhcp_timeout () != 0) { |
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279 | remove_address(ifp->name); |
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280 | set_static_address (ifp); /* use static ip-address if dhcp failed */ |
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281 | } |
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282 | |
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283 | } |
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284 | |
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285 | /* |
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286 | * Main dhcp monitor thread |
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287 | */ |
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288 | static void dhcp_monitor_task (rtems_task_argument ifp_arg) |
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289 | { |
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290 | struct rtems_bsdnet_ifconfig *ifp = (struct rtems_bsdnet_ifconfig *)ifp_arg; |
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291 | char *ifname = ifp->name; |
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292 | unsigned int downcount = 0; |
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293 | int16_t ifflags; |
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294 | int must_renew = FALSE; |
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295 | |
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296 | while (TRUE) { |
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297 | if (rtems_bsdnet_ifconfig(ifname, SIOCGIFFLAGS, &ifflags) < 0) { |
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298 | printf ("Failed to get if flags: %s (%d)\n", strerror (errno), errno); |
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299 | goto error_out; |
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300 | } |
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301 | |
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302 | if ((ifflags & IFF_RUNNING) != 0) { |
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303 | if(must_renew) { |
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304 | must_renew = FALSE; |
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305 | do_dhcp_init(ifp); |
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306 | } |
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307 | downcount = 0; |
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308 | } else { |
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309 | if (downcount < network_fail_timeout) { |
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310 | downcount++; |
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311 | |
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312 | if (downcount == network_fail_timeout) { |
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313 | printf ("lost network connection...\n"); |
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314 | rtems_bsdnet_dhcp_down (); |
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315 | must_renew = TRUE; |
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316 | dhcp_if_down(ifname); |
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317 | rtems_task_wake_after(RTEMS_MILLISECONDS_TO_TICKS(network_down_time * 1000)); |
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318 | dhcp_if_up(ifname); |
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319 | downcount = 0; |
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320 | } |
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321 | } |
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322 | } |
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323 | |
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324 | rtems_task_wake_after(RTEMS_MILLISECONDS_TO_TICKS(1000)); |
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325 | } |
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326 | |
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327 | error_out: |
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328 | printf("Stopping dhcp monitoring application.\n"); |
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329 | rtems_task_delete(RTEMS_SELF); |
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330 | } |
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331 | |
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332 | /* |
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333 | * initialize dhcp monitoring application |
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334 | * start dhcp monitoring thread |
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335 | */ |
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336 | void rtems_bsdnet_do_dhcp_failsafe (void) |
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337 | { |
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338 | rtems_status_code sc; |
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339 | rtems_id id; |
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340 | struct rtems_bsdnet_ifconfig *ifp; |
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341 | int16_t ifflags; |
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342 | |
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343 | /* Find a suitable interface */ |
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344 | for (ifp = rtems_bsdnet_config.ifconfig; ifp; ifp = ifp->next) { |
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345 | if (rtems_bsdnet_ifconfig (ifp->name, SIOCGIFFLAGS, &ifflags) < 0) |
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346 | continue; |
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347 | if ((ifflags & (IFF_LOOPBACK | IFF_POINTOPOINT)) == 0) |
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348 | break; |
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349 | } |
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350 | if (ifp == NULL){ |
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351 | printf ("dhcpc_failsafe: no suitable interface\n"); |
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352 | return; |
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353 | } |
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354 | printf("starting dhcp on interface %s\n", ifp->name); |
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355 | do_dhcp_init(ifp); |
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356 | |
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357 | if (network_fail_timeout) { |
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358 | sc = rtems_task_create (rtems_build_name ('d','h','c','m'), |
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359 | dhcp_monitor_priority, |
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360 | 2048, |
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361 | RTEMS_PREEMPT | |
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362 | RTEMS_NO_TIMESLICE | |
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363 | RTEMS_NO_ASR | |
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364 | RTEMS_INTERRUPT_LEVEL (0), |
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365 | RTEMS_LOCAL, |
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366 | &id); |
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367 | |
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368 | if (sc != RTEMS_SUCCESSFUL) { |
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369 | printf ("Failed to create dhcp monitor task, code %d\n", sc); |
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370 | return; |
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371 | } |
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372 | |
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373 | sc = rtems_task_start (id, dhcp_monitor_task, (rtems_task_argument) ifp); |
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374 | |
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375 | if (sc != RTEMS_SUCCESSFUL) { |
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376 | printf ("Failed to start dhcp monitor task, code %d\n", sc); |
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377 | } |
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378 | } |
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379 | } |
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380 | |
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