[821] | 1 | /*
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| 2 | * files.c -- DHCP server file manipulation *
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| 3 | * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
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| 4 | */
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| 5 |
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| 6 | #include <sys/socket.h>
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| 7 | #include <arpa/inet.h>
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| 8 | #include <string.h>
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| 9 | #include <stdlib.h>
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| 10 | #include <time.h>
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| 11 | #include <ctype.h>
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| 12 | #include <netdb.h>
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| 13 |
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| 14 | #include <netinet/ether.h>
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| 15 | #include "static_leases.h"
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| 16 |
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| 17 | #include "dhcpd.h"
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| 18 | #include "options.h"
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| 19 | #include "files.h"
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| 20 | #include "common.h"
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| 21 |
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| 22 | /*
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| 23 | * Domain names may have 254 chars, and string options can be 254
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| 24 | * chars long. However, 80 bytes will be enough for most, and won't
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| 25 | * hog up memory. If you have a special application, change it
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| 26 | */
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| 27 | #define READ_CONFIG_BUF_SIZE 80
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| 28 |
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| 29 | /* on these functions, make sure you datatype matches */
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| 30 | static int read_ip(const char *line, void *arg)
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| 31 | {
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| 32 | struct in_addr *addr = arg;
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| 33 | struct hostent *host;
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| 34 | int retval = 1;
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| 35 |
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| 36 | if (!inet_aton(line, addr)) {
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| 37 | if ((host = gethostbyname(line)))
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| 38 | addr->s_addr = *((unsigned long *) host->h_addr_list[0]);
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| 39 | else retval = 0;
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| 40 | }
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| 41 | return retval;
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| 42 | }
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| 43 |
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| 44 | static int read_mac(const char *line, void *arg)
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| 45 | {
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| 46 | uint8_t *mac_bytes = arg;
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| 47 | struct ether_addr *temp_ether_addr;
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| 48 | int retval = 1;
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| 49 |
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| 50 | temp_ether_addr = ether_aton(line);
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| 51 |
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| 52 | if(temp_ether_addr == NULL)
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| 53 | retval = 0;
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| 54 | else
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| 55 | memcpy(mac_bytes, temp_ether_addr, 6);
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| 56 |
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| 57 | return retval;
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| 58 | }
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| 59 |
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| 60 |
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| 61 | static int read_str(const char *line, void *arg)
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| 62 | {
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| 63 | char **dest = arg;
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| 64 |
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| 65 | free(*dest);
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| 66 | *dest = strdup(line);
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| 67 |
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| 68 | return 1;
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| 69 | }
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| 70 |
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| 71 |
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| 72 | static int read_u32(const char *line, void *arg)
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| 73 | {
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| 74 | uint32_t *dest = arg;
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| 75 | char *endptr;
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| 76 | *dest = strtoul(line, &endptr, 0);
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| 77 | return endptr[0] == '\0';
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| 78 | }
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| 79 |
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| 80 |
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| 81 | static int read_yn(const char *line, void *arg)
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| 82 | {
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| 83 | char *dest = arg;
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| 84 | int retval = 1;
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| 85 |
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| 86 | if (!strcasecmp("yes", line))
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| 87 | *dest = 1;
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| 88 | else if (!strcasecmp("no", line))
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| 89 | *dest = 0;
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| 90 | else retval = 0;
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| 91 |
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| 92 | return retval;
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| 93 | }
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| 94 |
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| 95 |
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| 96 | /* find option 'code' in opt_list */
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| 97 | struct option_set *find_option(struct option_set *opt_list, char code)
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| 98 | {
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| 99 | while (opt_list && opt_list->data[OPT_CODE] < code)
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| 100 | opt_list = opt_list->next;
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| 101 |
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| 102 | if (opt_list && opt_list->data[OPT_CODE] == code) return opt_list;
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| 103 | else return NULL;
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| 104 | }
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| 105 |
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| 106 |
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| 107 | /* add an option to the opt_list */
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| 108 | static void attach_option(struct option_set **opt_list, struct dhcp_option *option, char *buffer, int length)
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| 109 | {
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| 110 | struct option_set *existing, *new, **curr;
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| 111 |
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| 112 | /* add it to an existing option */
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| 113 | if ((existing = find_option(*opt_list, option->code))) {
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| 114 | DEBUG(LOG_INFO, "Attaching option %s to existing member of list", option->name);
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| 115 | if (option->flags & OPTION_LIST) {
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| 116 | if (existing->data[OPT_LEN] + length <= 255) {
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| 117 | existing->data = realloc(existing->data,
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| 118 | existing->data[OPT_LEN] + length + 2);
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| 119 | memcpy(existing->data + existing->data[OPT_LEN] + 2, buffer, length);
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| 120 | existing->data[OPT_LEN] += length;
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| 121 | } /* else, ignore the data, we could put this in a second option in the future */
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| 122 | } /* else, ignore the new data */
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| 123 | } else {
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| 124 | DEBUG(LOG_INFO, "Attaching option %s to list", option->name);
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| 125 |
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| 126 | /* make a new option */
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| 127 | new = xmalloc(sizeof(struct option_set));
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| 128 | new->data = xmalloc(length + 2);
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| 129 | new->data[OPT_CODE] = option->code;
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| 130 | new->data[OPT_LEN] = length;
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| 131 | memcpy(new->data + 2, buffer, length);
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| 132 |
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| 133 | curr = opt_list;
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| 134 | while (*curr && (*curr)->data[OPT_CODE] < option->code)
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| 135 | curr = &(*curr)->next;
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| 136 |
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| 137 | new->next = *curr;
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| 138 | *curr = new;
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| 139 | }
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| 140 | }
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| 141 |
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| 142 |
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| 143 | /* read a dhcp option and add it to opt_list */
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| 144 | static int read_opt(const char *const_line, void *arg)
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| 145 | {
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| 146 | struct option_set **opt_list = arg;
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| 147 | char *opt, *val, *endptr;
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| 148 | struct dhcp_option *option;
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| 149 | int retval = 0, length;
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| 150 | char buffer[8];
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| 151 | char *line;
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| 152 | uint16_t *result_u16 = (uint16_t *) buffer;
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| 153 | uint32_t *result_u32 = (uint32_t *) buffer;
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| 154 |
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| 155 | /* Cheat, the only const line we'll actually get is "" */
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| 156 | line = (char *) const_line;
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| 157 | if (!(opt = strtok(line, " \t="))) return 0;
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| 158 |
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| 159 | for (option = dhcp_options; option->code; option++)
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| 160 | if (!strcasecmp(option->name, opt))
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| 161 | break;
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| 162 |
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| 163 | if (!option->code) return 0;
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| 164 |
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| 165 | do {
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| 166 | if (!(val = strtok(NULL, ", \t"))) break;
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| 167 | length = option_lengths[option->flags & TYPE_MASK];
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| 168 | retval = 0;
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| 169 | opt = buffer; /* new meaning for variable opt */
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| 170 | switch (option->flags & TYPE_MASK) {
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| 171 | case OPTION_IP:
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| 172 | retval = read_ip(val, buffer);
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| 173 | break;
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| 174 | case OPTION_IP_PAIR:
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| 175 | retval = read_ip(val, buffer);
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| 176 | if (!(val = strtok(NULL, ", \t/-"))) retval = 0;
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| 177 | if (retval) retval = read_ip(val, buffer + 4);
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| 178 | break;
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| 179 | case OPTION_STRING:
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| 180 | length = strlen(val);
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| 181 | if (length > 0) {
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| 182 | if (length > 254) length = 254;
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| 183 | opt = val;
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| 184 | retval = 1;
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| 185 | }
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| 186 | break;
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| 187 | case OPTION_BOOLEAN:
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| 188 | retval = read_yn(val, buffer);
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| 189 | break;
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| 190 | case OPTION_U8:
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| 191 | buffer[0] = strtoul(val, &endptr, 0);
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| 192 | retval = (endptr[0] == '\0');
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| 193 | break;
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| 194 | case OPTION_U16:
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| 195 | *result_u16 = htons(strtoul(val, &endptr, 0));
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| 196 | retval = (endptr[0] == '\0');
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| 197 | break;
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| 198 | case OPTION_S16:
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| 199 | *result_u16 = htons(strtol(val, &endptr, 0));
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| 200 | retval = (endptr[0] == '\0');
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| 201 | break;
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| 202 | case OPTION_U32:
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| 203 | *result_u32 = htonl(strtoul(val, &endptr, 0));
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| 204 | retval = (endptr[0] == '\0');
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| 205 | break;
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| 206 | case OPTION_S32:
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| 207 | *result_u32 = htonl(strtol(val, &endptr, 0));
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| 208 | retval = (endptr[0] == '\0');
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| 209 | break;
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| 210 | default:
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| 211 | break;
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| 212 | }
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| 213 | if (retval)
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| 214 | attach_option(opt_list, option, opt, length);
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| 215 | } while (retval && option->flags & OPTION_LIST);
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| 216 | return retval;
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| 217 | }
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| 218 |
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| 219 | static int read_staticlease(const char *const_line, void *arg)
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| 220 | {
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| 221 |
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| 222 | char *line;
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| 223 | char *mac_string;
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| 224 | char *ip_string;
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| 225 | uint8_t *mac_bytes;
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| 226 | uint32_t *ip;
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| 227 |
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| 228 |
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| 229 | /* Allocate memory for addresses */
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| 230 | mac_bytes = xmalloc(sizeof(unsigned char) * 8);
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| 231 | ip = xmalloc(sizeof(uint32_t));
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| 232 |
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| 233 | /* Read mac */
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| 234 | line = (char *) const_line;
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| 235 | mac_string = strtok(line, " \t");
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| 236 | read_mac(mac_string, mac_bytes);
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| 237 |
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| 238 | /* Read ip */
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| 239 | ip_string = strtok(NULL, " \t");
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| 240 | read_ip(ip_string, ip);
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| 241 |
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| 242 | addStaticLease(arg, mac_bytes, ip);
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| 243 |
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| 244 | if (ENABLE_FEATURE_UDHCP_DEBUG) printStaticLeases(arg);
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| 245 |
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| 246 | return 1;
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| 247 |
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| 248 | }
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| 249 |
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| 250 |
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| 251 | static const struct config_keyword keywords[] = {
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| 252 | /* keyword handler variable address default */
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| 253 | {"start", read_ip, &(server_config.start), "192.168.0.20"},
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| 254 | {"end", read_ip, &(server_config.end), "192.168.0.254"},
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| 255 | {"interface", read_str, &(server_config.interface), "eth0"},
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| 256 | {"option", read_opt, &(server_config.options), ""},
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| 257 | {"opt", read_opt, &(server_config.options), ""},
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| 258 | {"max_leases", read_u32, &(server_config.max_leases), "254"},
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| 259 | {"remaining", read_yn, &(server_config.remaining), "yes"},
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| 260 | {"auto_time", read_u32, &(server_config.auto_time), "7200"},
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| 261 | {"decline_time",read_u32, &(server_config.decline_time),"3600"},
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| 262 | {"conflict_time",read_u32,&(server_config.conflict_time),"3600"},
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| 263 | {"offer_time", read_u32, &(server_config.offer_time), "60"},
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| 264 | {"min_lease", read_u32, &(server_config.min_lease), "60"},
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| 265 | {"lease_file", read_str, &(server_config.lease_file), LEASES_FILE},
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| 266 | {"pidfile", read_str, &(server_config.pidfile), "/var/run/udhcpd.pid"},
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| 267 | {"notify_file", read_str, &(server_config.notify_file), ""},
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| 268 | {"siaddr", read_ip, &(server_config.siaddr), "0.0.0.0"},
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| 269 | {"sname", read_str, &(server_config.sname), ""},
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| 270 | {"boot_file", read_str, &(server_config.boot_file), ""},
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| 271 | {"static_lease",read_staticlease, &(server_config.static_leases), ""},
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| 272 | /*ADDME: static lease */
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| 273 | {"", NULL, NULL, ""}
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| 274 | };
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| 275 |
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| 276 |
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| 277 | int read_config(const char *file)
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| 278 | {
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| 279 | FILE *in;
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| 280 | char buffer[READ_CONFIG_BUF_SIZE], *token, *line;
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| 281 | int i, lm = 0;
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| 282 |
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| 283 | for (i = 0; keywords[i].keyword[0]; i++)
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| 284 | if (keywords[i].def[0])
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| 285 | keywords[i].handler(keywords[i].def, keywords[i].var);
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| 286 |
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| 287 | if (!(in = fopen(file, "r"))) {
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| 288 | LOG(LOG_ERR, "unable to open config file: %s", file);
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| 289 | return 0;
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| 290 | }
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| 291 |
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| 292 | while (fgets(buffer, READ_CONFIG_BUF_SIZE, in)) {
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| 293 | char debug_orig[READ_CONFIG_BUF_SIZE];
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| 294 |
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| 295 | lm++;
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| 296 | if (strchr(buffer, '\n')) *(strchr(buffer, '\n')) = '\0';
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| 297 | if (ENABLE_FEATURE_UDHCP_DEBUG) strcpy(debug_orig, buffer);
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| 298 | if (strchr(buffer, '#')) *(strchr(buffer, '#')) = '\0';
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| 299 |
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| 300 | if (!(token = strtok(buffer, " \t"))) continue;
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| 301 | if (!(line = strtok(NULL, ""))) continue;
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| 302 |
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| 303 | /* eat leading whitespace */
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| 304 | line = line + strspn(line, " \t=");
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| 305 | /* eat trailing whitespace */
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| 306 | for (i = strlen(line); i > 0 && isspace(line[i - 1]); i--);
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| 307 | line[i] = '\0';
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| 308 |
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| 309 | for (i = 0; keywords[i].keyword[0]; i++)
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| 310 | if (!strcasecmp(token, keywords[i].keyword))
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| 311 | if (!keywords[i].handler(line, keywords[i].var)) {
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| 312 | LOG(LOG_ERR, "Failure parsing line %d of %s", lm, file);
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| 313 | DEBUG(LOG_ERR, "unable to parse '%s'", debug_orig);
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| 314 | /* reset back to the default value */
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| 315 | keywords[i].handler(keywords[i].def, keywords[i].var);
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| 316 | }
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| 317 | }
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| 318 | fclose(in);
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| 319 | return 1;
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| 320 | }
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| 321 |
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| 322 |
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| 323 | void write_leases(void)
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| 324 | {
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| 325 | FILE *fp;
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| 326 | unsigned int i;
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| 327 | char buf[255];
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| 328 | time_t curr = time(0);
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| 329 | unsigned long tmp_time;
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| 330 |
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| 331 | if (!(fp = fopen(server_config.lease_file, "w"))) {
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| 332 | LOG(LOG_ERR, "Unable to open %s for writing", server_config.lease_file);
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| 333 | return;
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| 334 | }
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| 335 |
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| 336 | for (i = 0; i < server_config.max_leases; i++) {
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| 337 | if (leases[i].yiaddr != 0) {
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| 338 |
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| 339 | /* screw with the time in the struct, for easier writing */
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| 340 | tmp_time = leases[i].expires;
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| 341 |
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| 342 | if (server_config.remaining) {
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| 343 | if (lease_expired(&(leases[i])))
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| 344 | leases[i].expires = 0;
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| 345 | else leases[i].expires -= curr;
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| 346 | } /* else stick with the time we got */
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| 347 | leases[i].expires = htonl(leases[i].expires);
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| 348 | fwrite(&leases[i], sizeof(struct dhcpOfferedAddr), 1, fp);
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| 349 |
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| 350 | /* Then restore it when done. */
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| 351 | leases[i].expires = tmp_time;
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| 352 | }
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| 353 | }
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| 354 | fclose(fp);
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| 355 |
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| 356 | if (server_config.notify_file) {
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| 357 | sprintf(buf, "%s %s", server_config.notify_file, server_config.lease_file);
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| 358 | system(buf);
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| 359 | }
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| 360 | }
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| 361 |
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| 362 |
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| 363 | void read_leases(const char *file)
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| 364 | {
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| 365 | FILE *fp;
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| 366 | unsigned int i = 0;
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| 367 | struct dhcpOfferedAddr lease;
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| 368 |
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| 369 | if (!(fp = fopen(file, "r"))) {
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| 370 | LOG(LOG_ERR, "Unable to open %s for reading", file);
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| 371 | return;
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| 372 | }
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| 373 |
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| 374 | while (i < server_config.max_leases && (fread(&lease, sizeof lease, 1, fp) == 1)) {
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| 375 | /* ADDME: is it a static lease */
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| 376 | if (lease.yiaddr >= server_config.start && lease.yiaddr <= server_config.end) {
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| 377 | lease.expires = ntohl(lease.expires);
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| 378 | if (!server_config.remaining) lease.expires -= time(0);
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| 379 | if (!(add_lease(lease.chaddr, lease.yiaddr, lease.expires))) {
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| 380 | LOG(LOG_WARNING, "Too many leases while loading %s\n", file);
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| 381 | break;
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| 382 | }
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| 383 | i++;
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| 384 | }
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| 385 | }
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| 386 | DEBUG(LOG_INFO, "Read %d leases", i);
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| 387 | fclose(fp);
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| 388 | }
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