| 1 | /*************************************************************************** |
| 2 | * Copyright (C) 2004 by Intra2net AG * |
| 3 | * opensource@intra2net.com * |
| 4 | * * |
| 5 | * This program is free software; you can redistribute it and/or modify * |
| 6 | * it under the terms of the GNU Lesser General Public License * |
| 7 | * version 2.1 as published by the Free Software Foundation; * |
| 8 | * * |
| 9 | ***************************************************************************/ |
| 10 | |
| 11 | #include <sys/types.h> |
| 12 | #include <sys/socket.h> |
| 13 | |
| 14 | #include <netinet/in.h> |
| 15 | #include <linux/if.h> |
| 16 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 17 | #include <ipt_ACCOUNT_cl.h> |
| 18 | |
| 19 | int ipt_ACCOUNT_init(struct ipt_ACCOUNT_context *ctx) |
| 20 | { |
| 21 | memset (ctx, 0, sizeof(struct ipt_ACCOUNT_context)); |
| 22 | |
| 23 | ctx->sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW); |
| 24 | if (ctx->sockfd < 0) |
| 25 | { |
| 26 | ctx->sockfd = -1; |
| 27 | ctx->error_str = "Can't open socket to kernel. Permission denied or ipt_ACCOUNT module not loaded"; |
| 28 | return -1; |
| 29 | } |
| 30 | |
| 31 | // 4096 bytes default buffer should save us from reallocations |
| 32 | // as it fits 200 concurrent active clients |
| 33 | if((ctx->data = (void *)malloc(IPT_ACCOUNT_MIN_BUFSIZE)) == NULL) |
| 34 | { |
| 35 | close (ctx->sockfd); |
| 36 | ctx->sockfd = -1; |
| 37 | ctx->error_str = "Out of memory for data buffer"; |
| 38 | return -1; |
| 39 | } |
| 40 | ctx->data_size = IPT_ACCOUNT_MIN_BUFSIZE; |
| 41 | |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | void ipt_ACCOUNT_free_entries(struct ipt_ACCOUNT_context *ctx) |
| 46 | { |
| 47 | if (ctx->handle.handle_nr != -1) |
| 48 | { |
| 49 | setsockopt(ctx->sockfd, IPPROTO_IP, IPT_SO_SET_ACCOUNT_HANDLE_FREE, &ctx->handle, sizeof (struct ipt_account_handle_sockopt)); |
| 50 | ctx->handle.handle_nr = -1; |
| 51 | } |
| 52 | |
| 53 | ctx->handle.itemcount = 0; |
| 54 | ctx->pos = 0; |
| 55 | } |
| 56 | |
| 57 | void ipt_ACCOUNT_deinit(struct ipt_ACCOUNT_context *ctx) |
| 58 | { |
| 59 | free(ctx->data); |
| 60 | ctx->data = NULL; |
| 61 | |
| 62 | ipt_ACCOUNT_free_entries(ctx); |
| 63 | |
| 64 | close(ctx->sockfd); |
| 65 | ctx->sockfd =-1; |
| 66 | } |
| 67 | |
| 68 | int ipt_ACCOUNT_read_entries(struct ipt_ACCOUNT_context *ctx, char *table, char dont_flush) |
| 69 | { |
| 70 | unsigned int s = sizeof (struct ipt_account_handle_sockopt); |
| 71 | int rtn; |
| 72 | |
| 73 | strncpy(ctx->handle.name, table, ACCOUNT_TABLE_NAME_LEN-1); |
| 74 | |
| 75 | // Get table information |
| 76 | if (!dont_flush) |
| 77 | rtn = getsockopt(ctx->sockfd, IPPROTO_IP, IPT_SO_GET_ACCOUNT_PREPARE_READ_FLUSH, &ctx->handle, &s); |
| 78 | else |
| 79 | rtn = getsockopt(ctx->sockfd, IPPROTO_IP, IPT_SO_GET_ACCOUNT_PREPARE_READ, &ctx->handle, &s); |
| 80 | |
| 81 | if (rtn < 0) |
| 82 | { |
| 83 | ctx->error_str = "Can't get table information from kernel. Is the table existing?"; |
| 84 | return -1; |
| 85 | } |
| 86 | |
| 87 | // Check data buffer size |
| 88 | ctx->pos = 0; |
| 89 | unsigned int new_size = ctx->handle.itemcount * sizeof(struct ipt_account_handle_ip); |
| 90 | // We want to prevent reallocations all the time |
| 91 | if (new_size < IPT_ACCOUNT_MIN_BUFSIZE) |
| 92 | new_size = IPT_ACCOUNT_MIN_BUFSIZE; |
| 93 | |
| 94 | // Reallocate if it's too small or twice as big |
| 95 | if (ctx->data_size < new_size || ctx->data_size > new_size*2) |
| 96 | { |
| 97 | // Free old buffer |
| 98 | free (ctx->data); |
| 99 | ctx->data_size = 0; |
| 100 | |
| 101 | if ((ctx->data = (void*)malloc(new_size)) == NULL) |
| 102 | { |
| 103 | ctx->error_str = "Out of memory for data buffer"; |
| 104 | ipt_ACCOUNT_free_entries(ctx); |
| 105 | return -1; |
| 106 | } |
| 107 | |
| 108 | ctx->data_size = new_size; |
| 109 | } |
| 110 | |
| 111 | // Copy data from kernel |
| 112 | memcpy(ctx->data, &ctx->handle, sizeof(struct ipt_account_handle_sockopt)); |
| 113 | rtn = getsockopt(ctx->sockfd, IPPROTO_IP, IPT_SO_GET_ACCOUNT_GET_DATA, ctx->data, &ctx->data_size); |
| 114 | if (rtn < 0) |
| 115 | { |
| 116 | ctx->error_str = "Can't get data from kernel. Check /var/log/messages for details."; |
| 117 | ipt_ACCOUNT_free_entries(ctx); |
| 118 | return -1; |
| 119 | } |
| 120 | |
| 121 | // Free kernel handle but don't reset pos/itemcount |
| 122 | setsockopt(ctx->sockfd, IPPROTO_IP, IPT_SO_SET_ACCOUNT_HANDLE_FREE, &ctx->handle, sizeof (struct ipt_account_handle_sockopt)); |
| 123 | ctx->handle.handle_nr = -1; |
| 124 | |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | struct ipt_account_handle_ip *ipt_ACCOUNT_get_next_entry(struct ipt_ACCOUNT_context *ctx) |
| 129 | { |
| 130 | struct ipt_account_handle_ip *rtn; |
| 131 | |
| 132 | // Empty or no more items left to return? |
| 133 | if (!ctx->handle.itemcount || ctx->pos >= ctx->handle.itemcount) |
| 134 | return NULL; |
| 135 | |
| 136 | // Get next entry |
| 137 | rtn = (struct ipt_account_handle_ip *)(ctx->data + ctx->pos*sizeof(struct ipt_account_handle_ip)); |
| 138 | ctx->pos++; |
| 139 | |
| 140 | return rtn; |
| 141 | } |
| 142 | |
| 143 | int ipt_ACCOUNT_get_handle_usage(struct ipt_ACCOUNT_context *ctx) |
| 144 | { |
| 145 | unsigned int s = sizeof (struct ipt_account_handle_sockopt); |
| 146 | if (getsockopt(ctx->sockfd, IPPROTO_IP, IPT_SO_GET_ACCOUNT_GET_HANDLE_USAGE, &ctx->handle, &s) < 0) |
| 147 | { |
| 148 | ctx->error_str = "Can't get handle usage information from kernel"; |
| 149 | return -1; |
| 150 | } |
| 151 | |
| 152 | return ctx->handle.itemcount; |
| 153 | } |
| 154 | |
| 155 | int ipt_ACCOUNT_free_all_handles(struct ipt_ACCOUNT_context *ctx) |
| 156 | { |
| 157 | if (setsockopt(ctx->sockfd, IPPROTO_IP, IPT_SO_SET_ACCOUNT_HANDLE_FREE_ALL, NULL, 0) < 0) |
| 158 | { |
| 159 | ctx->error_str = "Can't free all kernel handles"; |
| 160 | return -1; |
| 161 | } |
| 162 | |
| 163 | return 0; |
| 164 | } |
| 165 | |
| 166 | int ipt_ACCOUNT_get_table_names(struct ipt_ACCOUNT_context *ctx) |
| 167 | { |
| 168 | int rtn = getsockopt(ctx->sockfd, IPPROTO_IP, IPT_SO_GET_ACCOUNT_GET_TABLE_NAMES, ctx->data, &ctx->data_size); |
| 169 | if (rtn < 0) |
| 170 | { |
| 171 | ctx->error_str = "Can't get table names from kernel. Out of memory, MINBUFISZE too small?"; |
| 172 | return -1; |
| 173 | } |
| 174 | ctx->pos = 0; |
| 175 | return 0; |
| 176 | } |
| 177 | |
| 178 | char *ipt_ACCOUNT_get_next_name(struct ipt_ACCOUNT_context *ctx) |
| 179 | { |
| 180 | if (((char *)ctx->data)[ctx->pos] == NULL) |
| 181 | return NULL; |
| 182 | |
| 183 | char *rtn = ctx->data + ctx->pos; |
| 184 | ctx->pos += strlen(ctx->data+ctx->pos) + 1; |
| 185 | |
| 186 | return rtn; |
| 187 | } |