[1765] | 1 | /* vi: set sw=4 ts=4: */
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[821] | 2 | /*
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| 3 | * files.c -- DHCP server file manipulation *
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| 4 | * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
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| 5 | */
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| 6 |
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| 7 | #include <netinet/ether.h>
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| 8 |
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[1765] | 9 | #include "common.h"
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[821] | 10 | #include "dhcpd.h"
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| 11 | #include "options.h"
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| 12 |
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| 13 |
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[1765] | 14 | /* on these functions, make sure your datatype matches */
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[821] | 15 | static int read_ip(const char *line, void *arg)
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| 16 | {
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[1765] | 17 | len_and_sockaddr *lsa;
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[821] | 18 |
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[1765] | 19 | lsa = host_and_af2sockaddr(line, 0, AF_INET);
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| 20 | if (!lsa)
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| 21 | return 0;
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| 22 | *(uint32_t*)arg = lsa->sin.sin_addr.s_addr;
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| 23 | free(lsa);
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| 24 | return 1;
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[821] | 25 | }
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| 26 |
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| 27 | static int read_mac(const char *line, void *arg)
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| 28 | {
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| 29 | uint8_t *mac_bytes = arg;
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| 30 | struct ether_addr *temp_ether_addr;
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| 31 |
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| 32 | temp_ether_addr = ether_aton(line);
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[1765] | 33 | if (temp_ether_addr == NULL)
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| 34 | return 0;
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| 35 | memcpy(mac_bytes, temp_ether_addr, 6);
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| 36 | return 1;
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[821] | 37 | }
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| 38 |
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| 39 |
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| 40 | static int read_str(const char *line, void *arg)
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| 41 | {
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| 42 | char **dest = arg;
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| 43 |
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| 44 | free(*dest);
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[1765] | 45 | *dest = xstrdup(line);
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[821] | 46 | return 1;
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| 47 | }
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| 48 |
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| 49 |
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| 50 | static int read_u32(const char *line, void *arg)
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| 51 | {
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[1765] | 52 | *(uint32_t*)arg = bb_strtou32(line, NULL, 10);
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| 53 | return errno == 0;
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[821] | 54 | }
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| 55 |
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| 56 |
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| 57 | static int read_yn(const char *line, void *arg)
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| 58 | {
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| 59 | char *dest = arg;
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| 60 |
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[1765] | 61 | if (!strcasecmp("yes", line)) {
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[821] | 62 | *dest = 1;
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[1765] | 63 | return 1;
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| 64 | }
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| 65 | if (!strcasecmp("no", line)) {
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[821] | 66 | *dest = 0;
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[1765] | 67 | return 1;
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| 68 | }
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| 69 | return 0;
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[821] | 70 | }
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| 71 |
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| 72 |
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| 73 | /* find option 'code' in opt_list */
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| 74 | struct option_set *find_option(struct option_set *opt_list, char code)
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| 75 | {
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| 76 | while (opt_list && opt_list->data[OPT_CODE] < code)
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| 77 | opt_list = opt_list->next;
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| 78 |
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[1765] | 79 | if (opt_list && opt_list->data[OPT_CODE] == code)
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| 80 | return opt_list;
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| 81 | return NULL;
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[821] | 82 | }
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| 83 |
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| 84 |
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| 85 | /* add an option to the opt_list */
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[1765] | 86 | static void attach_option(struct option_set **opt_list,
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| 87 | const struct dhcp_option *option, char *buffer, int length)
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[821] | 88 | {
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| 89 | struct option_set *existing, *new, **curr;
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| 90 |
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[1765] | 91 | existing = find_option(*opt_list, option->code);
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| 92 | if (!existing) {
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| 93 | DEBUG("Attaching option %s to list", option->name);
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[821] | 94 |
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[1765] | 95 | #if ENABLE_FEATURE_RFC3397
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| 96 | if ((option->flags & TYPE_MASK) == OPTION_STR1035)
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| 97 | /* reuse buffer and length for RFC1035-formatted string */
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| 98 | buffer = dname_enc(NULL, 0, buffer, &length);
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| 99 | #endif
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| 100 |
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[821] | 101 | /* make a new option */
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[1765] | 102 | new = xmalloc(sizeof(*new));
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[821] | 103 | new->data = xmalloc(length + 2);
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| 104 | new->data[OPT_CODE] = option->code;
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| 105 | new->data[OPT_LEN] = length;
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| 106 | memcpy(new->data + 2, buffer, length);
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| 107 |
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| 108 | curr = opt_list;
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| 109 | while (*curr && (*curr)->data[OPT_CODE] < option->code)
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| 110 | curr = &(*curr)->next;
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| 111 |
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| 112 | new->next = *curr;
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| 113 | *curr = new;
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[1765] | 114 | #if ENABLE_FEATURE_RFC3397
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| 115 | if ((option->flags & TYPE_MASK) == OPTION_STR1035 && buffer != NULL)
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| 116 | free(buffer);
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| 117 | #endif
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| 118 | return;
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[821] | 119 | }
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[1765] | 120 |
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| 121 | /* add it to an existing option */
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| 122 | DEBUG("Attaching option %s to existing member of list", option->name);
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| 123 | if (option->flags & OPTION_LIST) {
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| 124 | #if ENABLE_FEATURE_RFC3397
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| 125 | if ((option->flags & TYPE_MASK) == OPTION_STR1035)
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| 126 | /* reuse buffer and length for RFC1035-formatted string */
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| 127 | buffer = dname_enc(existing->data + 2,
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| 128 | existing->data[OPT_LEN], buffer, &length);
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| 129 | #endif
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| 130 | if (existing->data[OPT_LEN] + length <= 255) {
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| 131 | existing->data = xrealloc(existing->data,
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| 132 | existing->data[OPT_LEN] + length + 3);
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| 133 | if ((option->flags & TYPE_MASK) == OPTION_STRING) {
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| 134 | /* ' ' can bring us to 256 - bad */
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| 135 | if (existing->data[OPT_LEN] + length >= 255)
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| 136 | return;
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| 137 | /* add space separator between STRING options in a list */
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| 138 | existing->data[existing->data[OPT_LEN] + 2] = ' ';
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| 139 | existing->data[OPT_LEN]++;
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| 140 | }
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| 141 | memcpy(existing->data + existing->data[OPT_LEN] + 2, buffer, length);
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| 142 | existing->data[OPT_LEN] += length;
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| 143 | } /* else, ignore the data, we could put this in a second option in the future */
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| 144 | #if ENABLE_FEATURE_RFC3397
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| 145 | if ((option->flags & TYPE_MASK) == OPTION_STR1035 && buffer != NULL)
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| 146 | free(buffer);
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| 147 | #endif
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| 148 | } /* else, ignore the new data */
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[821] | 149 | }
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| 150 |
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| 151 |
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| 152 | /* read a dhcp option and add it to opt_list */
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| 153 | static int read_opt(const char *const_line, void *arg)
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| 154 | {
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| 155 | struct option_set **opt_list = arg;
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| 156 | char *opt, *val, *endptr;
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[1765] | 157 | const struct dhcp_option *option;
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[821] | 158 | int retval = 0, length;
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| 159 | char buffer[8];
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| 160 | char *line;
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| 161 | uint16_t *result_u16 = (uint16_t *) buffer;
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| 162 | uint32_t *result_u32 = (uint32_t *) buffer;
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| 163 |
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| 164 | /* Cheat, the only const line we'll actually get is "" */
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| 165 | line = (char *) const_line;
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[1765] | 166 | opt = strtok(line, " \t=");
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| 167 | if (!opt) return 0;
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[821] | 168 |
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[1765] | 169 | option = dhcp_options;
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| 170 | while (1) {
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| 171 | if (!option->code)
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| 172 | return 0;
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[821] | 173 | if (!strcasecmp(option->name, opt))
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| 174 | break;
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[1765] | 175 | option++;
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| 176 | }
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[821] | 177 |
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| 178 | do {
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[1765] | 179 | val = strtok(NULL, ", \t");
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| 180 | if (!val) break;
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[821] | 181 | length = option_lengths[option->flags & TYPE_MASK];
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| 182 | retval = 0;
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| 183 | opt = buffer; /* new meaning for variable opt */
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| 184 | switch (option->flags & TYPE_MASK) {
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| 185 | case OPTION_IP:
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| 186 | retval = read_ip(val, buffer);
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| 187 | break;
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| 188 | case OPTION_IP_PAIR:
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| 189 | retval = read_ip(val, buffer);
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[1765] | 190 | val = strtok(NULL, ", \t/-");
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| 191 | if (!val)
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| 192 | retval = 0;
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| 193 | if (retval)
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| 194 | retval = read_ip(val, buffer + 4);
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[821] | 195 | break;
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| 196 | case OPTION_STRING:
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[1765] | 197 | #if ENABLE_FEATURE_RFC3397
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| 198 | case OPTION_STR1035:
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| 199 | #endif
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[821] | 200 | length = strlen(val);
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| 201 | if (length > 0) {
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| 202 | if (length > 254) length = 254;
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| 203 | opt = val;
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| 204 | retval = 1;
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| 205 | }
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| 206 | break;
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| 207 | case OPTION_BOOLEAN:
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| 208 | retval = read_yn(val, buffer);
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| 209 | break;
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| 210 | case OPTION_U8:
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| 211 | buffer[0] = strtoul(val, &endptr, 0);
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| 212 | retval = (endptr[0] == '\0');
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| 213 | break;
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[1765] | 214 | /* htonX are macros in older libc's, using temp var
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| 215 | * in code below for safety */
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| 216 | /* TODO: use bb_strtoX? */
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| 217 | case OPTION_U16: {
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| 218 | unsigned long tmp = strtoul(val, &endptr, 0);
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| 219 | *result_u16 = htons(tmp);
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| 220 | retval = (endptr[0] == '\0' /*&& tmp < 0x10000*/);
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[821] | 221 | break;
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[1765] | 222 | }
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| 223 | case OPTION_S16: {
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| 224 | long tmp = strtol(val, &endptr, 0);
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| 225 | *result_u16 = htons(tmp);
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[821] | 226 | retval = (endptr[0] == '\0');
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| 227 | break;
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[1765] | 228 | }
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| 229 | case OPTION_U32: {
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| 230 | unsigned long tmp = strtoul(val, &endptr, 0);
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| 231 | *result_u32 = htonl(tmp);
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[821] | 232 | retval = (endptr[0] == '\0');
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| 233 | break;
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[1765] | 234 | }
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| 235 | case OPTION_S32: {
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| 236 | long tmp = strtol(val, &endptr, 0);
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| 237 | *result_u32 = htonl(tmp);
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[821] | 238 | retval = (endptr[0] == '\0');
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| 239 | break;
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[1765] | 240 | }
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[821] | 241 | default:
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| 242 | break;
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| 243 | }
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| 244 | if (retval)
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| 245 | attach_option(opt_list, option, opt, length);
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| 246 | } while (retval && option->flags & OPTION_LIST);
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| 247 | return retval;
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| 248 | }
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| 249 |
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| 250 | static int read_staticlease(const char *const_line, void *arg)
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| 251 | {
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| 252 | char *line;
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| 253 | char *mac_string;
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| 254 | char *ip_string;
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| 255 | uint8_t *mac_bytes;
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| 256 | uint32_t *ip;
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| 257 |
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| 258 | /* Allocate memory for addresses */
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| 259 | mac_bytes = xmalloc(sizeof(unsigned char) * 8);
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| 260 | ip = xmalloc(sizeof(uint32_t));
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| 261 |
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| 262 | /* Read mac */
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| 263 | line = (char *) const_line;
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| 264 | mac_string = strtok(line, " \t");
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| 265 | read_mac(mac_string, mac_bytes);
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| 266 |
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| 267 | /* Read ip */
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| 268 | ip_string = strtok(NULL, " \t");
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| 269 | read_ip(ip_string, ip);
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| 270 |
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| 271 | addStaticLease(arg, mac_bytes, ip);
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| 272 |
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| 273 | if (ENABLE_FEATURE_UDHCP_DEBUG) printStaticLeases(arg);
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| 274 |
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| 275 | return 1;
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| 276 | }
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| 277 |
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| 278 |
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[1765] | 279 | struct config_keyword {
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| 280 | const char *keyword;
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| 281 | int (*handler)(const char *line, void *var);
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| 282 | void *var;
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| 283 | const char *def;
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| 284 | };
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| 285 |
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[821] | 286 | static const struct config_keyword keywords[] = {
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[1765] | 287 | /* keyword handler variable address default */
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| 288 | {"start", read_ip, &(server_config.start_ip), "192.168.0.20"},
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| 289 | {"end", read_ip, &(server_config.end_ip), "192.168.0.254"},
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| 290 | {"interface", read_str, &(server_config.interface), "eth0"},
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| 291 | {"option", read_opt, &(server_config.options), ""},
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| 292 | {"opt", read_opt, &(server_config.options), ""},
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| 293 | /* Avoid "max_leases value not sane" warning by setting default
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| 294 | * to default_end_ip - default_start_ip + 1: */
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| 295 | {"max_leases", read_u32, &(server_config.max_leases), "235"},
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| 296 | {"remaining", read_yn, &(server_config.remaining), "yes"},
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| 297 | {"auto_time", read_u32, &(server_config.auto_time), "7200"},
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| 298 | {"decline_time", read_u32, &(server_config.decline_time), "3600"},
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| 299 | {"conflict_time",read_u32, &(server_config.conflict_time),"3600"},
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| 300 | {"offer_time", read_u32, &(server_config.offer_time), "60"},
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| 301 | {"min_lease", read_u32, &(server_config.min_lease), "60"},
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| 302 | {"lease_file", read_str, &(server_config.lease_file), LEASES_FILE},
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| 303 | {"pidfile", read_str, &(server_config.pidfile), "/var/run/udhcpd.pid"},
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| 304 | {"notify_file", read_str, &(server_config.notify_file), ""},
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| 305 | {"siaddr", read_ip, &(server_config.siaddr), "0.0.0.0"},
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| 306 | {"sname", read_str, &(server_config.sname), ""},
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| 307 | {"boot_file", read_str, &(server_config.boot_file), ""},
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| 308 | {"static_lease", read_staticlease, &(server_config.static_leases), ""},
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| 309 | /* ADDME: static lease */
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[821] | 310 | };
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| 311 |
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| 312 |
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[1765] | 313 | /*
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| 314 | * Domain names may have 254 chars, and string options can be 254
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| 315 | * chars long. However, 80 bytes will be enough for most, and won't
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| 316 | * hog up memory. If you have a special application, change it
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| 317 | */
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| 318 | #define READ_CONFIG_BUF_SIZE 80
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| 319 |
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[821] | 320 | int read_config(const char *file)
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| 321 | {
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| 322 | FILE *in;
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| 323 | char buffer[READ_CONFIG_BUF_SIZE], *token, *line;
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| 324 | int i, lm = 0;
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| 325 |
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[1765] | 326 | for (i = 0; i < ARRAY_SIZE(keywords); i++)
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[821] | 327 | if (keywords[i].def[0])
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| 328 | keywords[i].handler(keywords[i].def, keywords[i].var);
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| 329 |
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[1765] | 330 | in = fopen_or_warn(file, "r");
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| 331 | if (!in) {
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[821] | 332 | return 0;
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| 333 | }
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| 334 |
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| 335 | while (fgets(buffer, READ_CONFIG_BUF_SIZE, in)) {
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| 336 | char debug_orig[READ_CONFIG_BUF_SIZE];
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[1765] | 337 | char *p;
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[821] | 338 |
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| 339 | lm++;
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[1765] | 340 | p = strchr(buffer, '\n');
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| 341 | if (p) *p = '\0';
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[821] | 342 | if (ENABLE_FEATURE_UDHCP_DEBUG) strcpy(debug_orig, buffer);
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[1765] | 343 | p = strchr(buffer, '#');
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| 344 | if (p) *p = '\0';
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[821] | 345 |
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| 346 | if (!(token = strtok(buffer, " \t"))) continue;
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| 347 | if (!(line = strtok(NULL, ""))) continue;
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| 348 |
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| 349 | /* eat leading whitespace */
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[1765] | 350 | line = skip_whitespace(line);
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[821] | 351 | /* eat trailing whitespace */
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[1765] | 352 | i = strlen(line) - 1;
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| 353 | while (i >= 0 && isspace(line[i]))
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| 354 | line[i--] = '\0';
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[821] | 355 |
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[1765] | 356 | for (i = 0; i < ARRAY_SIZE(keywords); i++)
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[821] | 357 | if (!strcasecmp(token, keywords[i].keyword))
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| 358 | if (!keywords[i].handler(line, keywords[i].var)) {
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[1765] | 359 | bb_error_msg("cannot parse line %d of %s", lm, file);
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| 360 | if (ENABLE_FEATURE_UDHCP_DEBUG)
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| 361 | bb_error_msg("cannot parse '%s'", debug_orig);
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[821] | 362 | /* reset back to the default value */
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| 363 | keywords[i].handler(keywords[i].def, keywords[i].var);
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| 364 | }
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| 365 | }
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| 366 | fclose(in);
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[1765] | 367 |
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| 368 | server_config.start_ip = ntohl(server_config.start_ip);
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| 369 | server_config.end_ip = ntohl(server_config.end_ip);
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| 370 |
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[821] | 371 | return 1;
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| 372 | }
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| 373 |
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| 374 |
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| 375 | void write_leases(void)
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| 376 | {
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[1765] | 377 | int fp;
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| 378 | unsigned i;
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[821] | 379 | time_t curr = time(0);
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| 380 | unsigned long tmp_time;
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| 381 |
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[1765] | 382 | fp = open3_or_warn(server_config.lease_file, O_WRONLY|O_CREAT|O_TRUNC, 0666);
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| 383 | if (fp < 0) {
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[821] | 384 | return;
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| 385 | }
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| 386 |
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| 387 | for (i = 0; i < server_config.max_leases; i++) {
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| 388 | if (leases[i].yiaddr != 0) {
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| 389 |
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| 390 | /* screw with the time in the struct, for easier writing */
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| 391 | tmp_time = leases[i].expires;
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| 392 |
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| 393 | if (server_config.remaining) {
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| 394 | if (lease_expired(&(leases[i])))
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| 395 | leases[i].expires = 0;
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| 396 | else leases[i].expires -= curr;
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| 397 | } /* else stick with the time we got */
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| 398 | leases[i].expires = htonl(leases[i].expires);
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[1765] | 399 | // FIXME: error check??
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| 400 | full_write(fp, &leases[i], sizeof(leases[i]));
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[821] | 401 |
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[1765] | 402 | /* then restore it when done */
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[821] | 403 | leases[i].expires = tmp_time;
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| 404 | }
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| 405 | }
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[1765] | 406 | close(fp);
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[821] | 407 |
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| 408 | if (server_config.notify_file) {
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[1765] | 409 | char *cmd = xasprintf("%s %s", server_config.notify_file, server_config.lease_file);
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| 410 | system(cmd);
|
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| 411 | free(cmd);
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[821] | 412 | }
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| 413 | }
|
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| 414 |
|
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| 415 |
|
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| 416 | void read_leases(const char *file)
|
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| 417 | {
|
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[1765] | 418 | int fp;
|
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[821] | 419 | unsigned int i = 0;
|
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| 420 | struct dhcpOfferedAddr lease;
|
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| 421 |
|
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[1765] | 422 | fp = open_or_warn(file, O_RDONLY);
|
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| 423 | if (fp < 0) {
|
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[821] | 424 | return;
|
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| 425 | }
|
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| 426 |
|
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[1765] | 427 | while (i < server_config.max_leases
|
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| 428 | && full_read(fp, &lease, sizeof(lease)) == sizeof(lease)
|
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| 429 | ) {
|
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[821] | 430 | /* ADDME: is it a static lease */
|
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[1765] | 431 | uint32_t y = ntohl(lease.yiaddr);
|
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| 432 | if (y >= server_config.start_ip && y <= server_config.end_ip) {
|
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[821] | 433 | lease.expires = ntohl(lease.expires);
|
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[1765] | 434 | if (!server_config.remaining)
|
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| 435 | lease.expires -= time(0);
|
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[821] | 436 | if (!(add_lease(lease.chaddr, lease.yiaddr, lease.expires))) {
|
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[1765] | 437 | bb_error_msg("too many leases while loading %s", file);
|
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[821] | 438 | break;
|
---|
| 439 | }
|
---|
| 440 | i++;
|
---|
| 441 | }
|
---|
| 442 | }
|
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[1765] | 443 | DEBUG("Read %d leases", i);
|
---|
| 444 | close(fp);
|
---|
[821] | 445 | }
|
---|