diff options
| -rw-r--r-- | usr.sbin/smtpd/spfwalk.c | 48 |
1 files changed, 45 insertions, 3 deletions
diff --git a/usr.sbin/smtpd/spfwalk.c b/usr.sbin/smtpd/spfwalk.c index 64de139d37d..cab05301de8 100644 --- a/usr.sbin/smtpd/spfwalk.c +++ b/usr.sbin/smtpd/spfwalk.c @@ -23,6 +23,7 @@ #include <asr.h> #include <ctype.h> #include <err.h> +#include <errno.h> #include <event.h> #include <pwd.h> #include <stdio.h> @@ -43,6 +44,7 @@ static void dispatch_a(struct dns_rr *); static void dispatch_aaaa(struct dns_rr *); static void lookup_record(int, const char *, void (*)(struct dns_rr *)); static void dispatch_record(struct asr_result *, void *); +static ssize_t parse_txt(const char *, size_t, char *, size_t); int ip_v4 = 0; int ip_v6 = 0; @@ -140,14 +142,19 @@ dispatch_record(struct asr_result *ar, void *arg) void dispatch_txt(struct dns_rr *rr) { - char buf[512]; + char buf[4096]; char buf2[512]; char *in = buf; char *argv[512]; char **ap = argv; char *end; - - print_dname(rr->rr.other.rdata, buf, sizeof(buf)); + ssize_t n; + + n = parse_txt(rr->rr.other.rdata, rr->rr.other.rdlen, buf, sizeof(buf)); + if (n == -1 || n == sizeof(buf)) + return; + buf[n] = '\0'; + if (strncasecmp("v=spf1 ", buf, 7)) return; @@ -238,3 +245,38 @@ dispatch_aaaa(struct dns_rr *rr) buffer, sizeof buffer))) printf("%s\n", ptr); } + +static ssize_t +parse_txt(const char *rdata, size_t rdatalen, char *dst, size_t dstsz) +{ + size_t len; + ssize_t r = 0; + + while (rdatalen) { + len = *(const unsigned char *)rdata; + if (len >= rdatalen) { + errno = EINVAL; + return -1; + } + + rdata++; + rdatalen--; + + if (len == 0) + continue; + + if (len >= dstsz) { + errno = EOVERFLOW; + return -1; + } + memmove(dst, rdata, len); + dst += len; + dstsz -= len; + + rdata += len; + rdatalen -= len; + r += len; + } + + return r; +} |