diff options
Diffstat (limited to 'src/libs6dns/s6dns_rci_init.c')
| -rw-r--r-- | src/libs6dns/s6dns_rci_init.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/src/libs6dns/s6dns_rci_init.c b/src/libs6dns/s6dns_rci_init.c new file mode 100644 index 0000000..a4f3fcf --- /dev/null +++ b/src/libs6dns/s6dns_rci_init.c @@ -0,0 +1,173 @@ +/* ISC license. */ + +#include <errno.h> +#include <skalibs/error.h> +#include <skalibs/bytestr.h> +#include <skalibs/bitarray.h> +#include <skalibs/fmtscan.h> +#include <skalibs/tai.h> +#include <skalibs/djbunix.h> +#include <skalibs/stralloc.h> +#include <skalibs/ip46.h> +#include <s6-dns/s6dns-constants.h> +#include <s6-dns/s6dns-rci.h> + +static unsigned int readit (char const *file, char *buf, unsigned int max) +{ + register int r = openreadnclose(file, buf, max - 1) ; + if (r < 0) + { + if (errno != ENOENT) return 0 ; + else r = 0 ; + } + buf[r++] = '\n' ; + return (unsigned int)r ; +} + +static inline int s6dns_rci_init_servers (s6dns_rci_t *rci, char const *file, char *tmp, unsigned int max, unsigned int *size) +{ + ip46_t tmplist[S6DNS_MAX_SERVERS] ; + unsigned int num = 0 ; + char const *x = env_get("DNSCACHEIP") ; + if (x) ip46_scanlist(tmplist, S6DNS_MAX_SERVERS, x, &num) ; + if (!num) + { + unsigned int i = 0 ; + *size = readit(file, tmp, max) ; + if (!*size) return 0 ; + while ((i < *size) && (num < S6DNS_MAX_SERVERS)) + { + register unsigned int j = byte_chr(tmp + i, *size - i, '\n') ; + if ((i + j < *size) && (j > 13U) && !byte_diff("nameserver", 10, tmp + i)) + { + register unsigned int k = 0 ; + while ((tmp[i+10+k] == ' ') || (tmp[i+10+k] == '\t')) k++ ; + if (k && ip46_scan(tmp+i+10+k, tmplist + num)) num++ ; + } + i += j + 1 ; + } + } + if (!num) + { + num = 1 ; + byte_copy(tmplist[0].ip, SKALIBS_IP_SIZE, S6DNS_LOCALHOST_IP) ; +#ifdef SKALIBS_IPV6_ENABLED + tmplist[0].is6 = 1 ; +#endif + } + + { + register unsigned int i = 0 ; + byte_zero(&rci->servers, sizeof(s6dns_ip46list_t)) ; + for (; i < num ; i++) + { + byte_copy(rci->servers.ip + SKALIBS_IP_SIZE * i, SKALIBS_IP_SIZE, tmplist[i].ip) ; +#ifdef SKALIBS_IPV6_ENABLED + if (ip46_is6(tmplist+i)) bitarray_set(rci->servers.is6, i) ; +#endif + } + } + return 1 ; +} + +static inline int stringrules (stralloc *rules, char const *s, unsigned int *num) +{ + unsigned int n = 0 ; + int crunching = 1 ; + int wasnull = !rules->s ; + unsigned int base = rules->len ; + char c = ' ' ; + while (c) + { + c = *s++ ; + if (byte_chr(" \t\n\r", 5, c) < 5) + { + if (!crunching) + { + if ((rules->s[rules->len - 1] != '.') && !stralloc_catb(rules, ".", 1)) goto err ; + if (!stralloc_0(rules)) goto err ; + n++ ; + crunching = 1 ; + } + } + else + { + if (crunching) crunching = 0 ; + if (!stralloc_catb(rules, &c, 1)) goto err ; + } + } + *num += n ; + return 1 ; + + err: + if (wasnull) stralloc_free(rules) ; + else rules->len = base ; + return 0 ; +} + +static inline int s6dns_rci_init_rules (s6dns_rci_t_ref rci, char const *file, char *tmp, unsigned int max, unsigned int *size) +{ + unsigned int num = 0 ; + char const *x = env_get("DNSQUALIFY") ; + if (x) + { + if (!stringrules(&rci->rules, x, &num)) return 0 ; + } + else + { + unsigned int i = 0 ; + if (!*size) + { + *size = readit(file, tmp, max) ; + if (!*size) return 0 ; + } + while (i < *size) + { + register unsigned int j = byte_chr(tmp + i, *size - i, '\n') ; + if ((i + j < *size) && (j > 8U) + && (!byte_diff("domain", 6, tmp + i) || !byte_diff("search", 6, tmp + i)) + && ((tmp[i+6] == ' ') || (tmp[i+6] == '\t') || (tmp[i+6] == '\r'))) + { + unsigned int k = 0 ; + int copying = 0 ; + register int notsearching = (tmp[i] != 's') ; + if (!stralloc_readyplus(&rci->rules, j)) return 0 ; + for (; 6 + k < j ; k++) + { + char c = tmp[i+7+k] ; + if ((c == ' ') || (c == '\t') || (c == '\r') || (c == '\n')) + { + if (copying) + { + copying = 0 ; + if ((tmp[i+6+k] != '.') && !stralloc_catb(&rci->rules, ".", 1)) return 0 ; + if (!stralloc_0(&rci->rules)) return 0 ; + num++ ; + if (notsearching) break ; + } + } + else + { + copying = 1 ; + if (!stralloc_catb(&rci->rules, &c, 1)) return 0 ; + } + } + } + i += j + 1 ; + } + } + if (!stralloc_0(&rci->rules)) return 0 ; /* empty rule to finish */ + num++ ; + rci->rulesnum = num ; + stralloc_shrink(&rci->rules) ; + return 1 ; +} + +int s6dns_rci_init (s6dns_rci_t *rci, char const *file) +{ + char tmp[4096] ; + unsigned int size = 0 ; + if (!s6dns_rci_init_servers(rci, file, tmp, 4096, &size)) return 0 ; + if (!s6dns_rci_init_rules(rci, file, tmp, 4096, &size)) return 0 ; + return 1 ; +} |