1 | /* mod_original_dst |
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2 | * version 1.0, released 2011-03-25 |
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3 | * Anders Kaseorg <andersk@mit.edu> |
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4 | * |
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5 | * This replaces the address of incoming connections with the original |
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6 | * destination, before any local masquerading (as given by |
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7 | * SO_ORIGINAL_DST). |
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8 | */ |
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9 | |
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10 | #include <sys/types.h> |
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11 | #include <sys/socket.h> |
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12 | #include <limits.h> |
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13 | #include <netdb.h> |
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14 | #include <linux/netfilter_ipv4.h> |
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15 | |
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16 | #include "ap_config.h" |
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17 | #include "ap_listen.h" |
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18 | #include "apr_portable.h" |
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19 | #include "http_config.h" |
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20 | #include "http_log.h" |
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21 | #include "httpd.h" |
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22 | #include "unixd.h" |
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23 | |
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24 | #define MPM_ACCEPT_FUNC ap_unixd_accept |
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25 | |
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26 | extern void apr_sockaddr_vars_set(apr_sockaddr_t *, int, apr_port_t); |
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27 | |
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28 | static apr_status_t original_dst_accept_func(void **accepted, ap_listen_rec *lr, apr_pool_t *ptrans) |
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29 | { |
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30 | apr_status_t status = MPM_ACCEPT_FUNC(accepted, lr, ptrans); |
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31 | if (status != APR_SUCCESS) |
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32 | return status; |
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33 | |
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34 | apr_socket_t *csd = *accepted; |
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35 | |
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36 | apr_sockaddr_t *local_addr; |
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37 | status = apr_socket_addr_get(&local_addr, APR_LOCAL, csd); |
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38 | if (status != APR_SUCCESS) { |
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39 | ap_log_perror(APLOG_MARK, APLOG_EMERG, status, ptrans, |
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40 | "original_dst_accept_func: apr_socket_addr_get failed"); |
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41 | apr_socket_close(csd); |
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42 | return APR_EGENERAL; |
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43 | } |
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44 | |
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45 | int sockdes; |
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46 | status = apr_os_sock_get(&sockdes, csd); |
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47 | if (status != APR_SUCCESS) { |
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48 | ap_log_perror(APLOG_MARK, APLOG_EMERG, status, ptrans, |
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49 | "original_dst_accept_func: apr_os_sock_get failed"); |
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50 | apr_socket_close(csd); |
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51 | return APR_EGENERAL; |
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52 | } |
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53 | |
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54 | socklen_t salen = sizeof(local_addr->sa); |
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55 | status = getsockopt(sockdes, SOL_IP, SO_ORIGINAL_DST, &local_addr->sa, &salen); |
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56 | if (status == 0) { |
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57 | local_addr->salen = salen; |
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58 | apr_sockaddr_vars_set(local_addr, local_addr->sa.sin.sin_family, htons(local_addr->sa.sin.sin_port)); |
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59 | return APR_SUCCESS; |
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60 | } else if (errno == ENOENT) { |
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61 | return APR_SUCCESS; |
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62 | } else { |
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63 | ap_log_perror(APLOG_MARK, APLOG_EMERG, errno, ptrans, |
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64 | "original_dst_accept_func: getsockopt failed"); |
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65 | apr_socket_close(csd); |
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66 | return APR_EGENERAL; |
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67 | } |
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68 | } |
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69 | |
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70 | static int original_dst_post_config(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s) |
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71 | { |
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72 | ap_listen_rec *lr; |
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73 | for (lr = ap_listeners; lr; lr = lr->next) |
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74 | if (lr->accept_func == MPM_ACCEPT_FUNC) |
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75 | lr->accept_func = original_dst_accept_func; |
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76 | return OK; |
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77 | } |
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78 | |
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79 | static void original_dst_register_hooks(apr_pool_t *p) |
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80 | { |
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81 | ap_hook_post_config(original_dst_post_config, NULL, NULL, APR_HOOK_MIDDLE); |
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82 | } |
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83 | |
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84 | module AP_MODULE_DECLARE_DATA original_dst_module = |
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85 | { |
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86 | STANDARD20_MODULE_STUFF, |
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87 | NULL, /* per-directory config creator */ |
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88 | NULL, /* dir config merger */ |
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89 | NULL, /* server config creator */ |
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90 | NULL, /* server config merger */ |
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91 | NULL, /* command table */ |
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92 | original_dst_register_hooks, /* set up other request processing hooks */ |
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93 | }; |
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