[Toybox] [PATCH 1/2] Adding a minimal nslookup frontend to host.c
Moritz Christian Weber
mo.c.weber at gmail.com
Tue Jan 3 13:20:25 PST 2023
Dear all,
please ignore this one, which was still pending in outgoing, but rolled
back by Rob..
Best regards,
Moritz
On Tue, Jan 3, 2023 at 10:18 PM Moritz C. Weber <mo.c.weber at gmail.com>
wrote:
> ---
> toys/net/host.c | 98 +++++++++++++++++++++++++++++++------------------
> 1 file changed, 63 insertions(+), 35 deletions(-)
>
> diff --git a/toys/net/host.c b/toys/net/host.c
> index 20331678..933f4fb7 100644
> --- a/toys/net/host.c
> +++ b/toys/net/host.c
> @@ -7,6 +7,7 @@
> * See https://www.ietf.org/rfc/rfc3596.txt
>
> USE_HOST(NEWTOY(host, "<1>2avt:", TOYFLAG_USR|TOYFLAG_BIN))
> +USE_NSLOOKUP(NEWTOY(nslookup, "<1>2", TOYFLAG_USR|TOYFLAG_BIN))
>
> config HOST
> bool "host"
> @@ -20,6 +21,14 @@ config HOST
> -a All records
> -t TYPE Record TYPE (number or ANY A AAAA CNAME MX NS PTR SOA SRV
> TXT)
> -v Verbose
> +
> +config NSLOOKUP
> + bool "nslookup"
> + default y
> + help
> + usage: nslookup NAME [SERVER]
> +
> + Query Internet name servers interactively
> */
>
> #define FOR_host
> @@ -70,13 +79,11 @@ static void get_nsname(char **pline, long len)
> }
> }
>
> -void host_main(void)
> +void lookup(int verbose, unsigned *ttl, char* t2, int t2len, int* type,
> int* rcode)
> {
> - int verbose = FLAG(a)||FLAG(v), type, abuf_len = 65536, //Largest TCP
> response
> - i, j, sec, rcode, qlen, alen QUIET, pllen = 0, t2len = 2048;
> - unsigned count, ttl;
> - char *abuf = xmalloc(abuf_len), *name = *toys.optargs, *p, *ss,
> - *t2 = toybuf+t2len;
> + int i, j, sec, qlen, alen QUIET, pllen = 0, abuf_len = 65536; //Largest
> TCP response
> + unsigned count;
> + char *abuf = xmalloc(abuf_len), *name = *toys.optargs, *p, *ss;
> struct addrinfo *ai;
>
> // What kind of query are we doing?
> @@ -96,26 +103,20 @@ void host_main(void)
> } else if (!TT.t) TT.t = "1";
>
> // Prepare query packet of appropriate type
> - if (TT.t[0]-'0'<10) type = atoi(TT.t); // TODO
> - else if (!strcasecmp(TT.t, "any") || strcmp(TT.t, "*")) type = 255;
> + if (TT.t[0]-'0'<10) *type = atoi(TT.t); // TODO
> + else if (!strcasecmp(TT.t, "any") || strcmp(TT.t, "*")) *type = 255;
> else {
> for (i = 0; i<ARRAY_LEN(rrt); i++) if (!strcasecmp(TT.t,
> rrt[i].name)) {
> - type = rrt[i].type;
> + *type = rrt[i].type;
> break;
> }
> if (i == ARRAY_LEN(rrt)) error_exit("bad -t: %s", TT.t);
> }
> - qlen = res_mkquery(0, name, 1, type, 0, 0, 0, t2, 280); //t2len);
> + qlen = res_mkquery(0, name, 1, *type, 0, 0, 0, t2, 280); //t2len);
> if (qlen<0) error_exit("bad NAME: %s", name);
>
> - // Grab nameservers
> - if (toys.optargs[1]) TT.nsname = toys.optargs+1;
> - else do_lines(xopen("/etc/resolv.conf", O_RDONLY), '\n', get_nsname);
> - if (!TT.nsname) error_exit("No nameservers");
> -
> // Send one query packet to each server until we receive response
> while (*TT.nsname) {
> - if (verbose) printf("Using domain server %s:\n", *TT.nsname);
> ai = xgetaddrinfo(*TT.nsname, "53", 0, SOCK_DGRAM, 0, 0);
> i = xsocket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
> xconnect(i, ai->ai_addr, ai->ai_addrlen);
> @@ -128,14 +129,14 @@ void host_main(void)
> }
>
> // Did it error?
> - rcode = abuf[3]&7;
> + *rcode = abuf[3]&7;
> if (verbose) {
> - printf("rcode = %d, ancount = %d\n", rcode, (int)peek_be(abuf+6, 2));
> + printf("rcode = %d, ancount = %d\n", *rcode, (int)peek_be(abuf+6, 2));
> if (!(abuf[2]&4)) puts("The following answer is not authoritative:");
> }
> - if (rcode) error_exit("Host not found: %s",
> + if (*rcode) error_exit("Host not found: %s",
> (char *[]){ "Format error", "Server failure",
> - "Non-existant domain", "Not implemented", "Refused", ""}[rcode-1]);
> + "Non-existant domain", "Not implemented", "Refused", ""}[*rcode-1]);
>
> // Print the result
> p = abuf + 12;
> @@ -148,20 +149,20 @@ void host_main(void)
> for (; count--; p += pllen) {
> p += xdn_expand(abuf, abuf+alen, p, toybuf, 4096-t2len);
> if (alen-(p-abuf)<10) error_exit("tilt");
> - type = peek_be(p, 2);
> + *type = peek_be(p, 2);
> p += 4;
> if (!sec) continue;
> - ttl = peek_be(p, 4);
> + *ttl = peek_be(p, 4);
> p += 4;
> pllen = peek_be(p, 2);
> p += 2;
> if ((p-abuf)+pllen>alen) error_exit("tilt");
>
> - if (type==1 || type == 28)
> - inet_ntop(type==1 ? AF_INET : AF_INET6, p, t2, t2len);
> - else if (type==2 || type==5) xdn_expand(abuf, abuf+alen, p, t2,
> t2len);
> - else if (type==16) sprintf(t2, "\"%.*s\"", minof(pllen, t2len), p);
> - else if (type==6) {
> + if (*type==1 || *type == 28)
> + inet_ntop(*type==1 ? AF_INET : AF_INET6, p, t2, t2len);
> + else if (*type==2 || *type==5) xdn_expand(abuf, abuf+alen, p, t2,
> t2len);
> + else if (*type==16) sprintf(t2, "\"%.*s\"", minof(pllen, t2len), p);
> + else if (*type==6) {
> ss = p+xdn_expand(abuf, abuf+alen, p, t2, t2len-1);
> j = strlen(t2);
> t2[j++] = ' ';
> @@ -172,25 +173,52 @@ void host_main(void)
> "\t\t%u\t;default ttl\n\t\t)", (unsigned)peek_be(ss, 4),
> (unsigned)peek_be(ss+4, 4), (unsigned)peek_be(ss+8, 4),
> (unsigned)peek_be(ss+12, 4), (unsigned)peek_be(ss+16, 4));
> - } else if (type==15) {
> + } else if (*type==15) {
> j = peek_be(p, 2);
> j = sprintf(t2, verbose ? "%d " : "(pri=%d) by ", j);
> xdn_expand(abuf, abuf+alen, p+2, t2+j, t2len-j);
> - } else if (type==33) {
> + } else if (*type==33) {
> j = sprintf(t2, "%u %u %u ", (int)peek_be(p, 2),
> (int)peek_be(p+2, 2),
> (int)peek_be(p+4, 2));
> xdn_expand(abuf, abuf+alen, p+6, t2+j, t2len-j);
> } else {
> - printf("%s unsupported RR type %u\n", toybuf, type);
> + printf("%s unsupported RR type %u\n", toybuf, *type);
> continue;
> }
> -
> - for (i = 0; rrt[i].type != type; i++);
> - if (verbose) printf("%s\t%u\tIN %s\t%s\n", toybuf, ttl,
> rrt[i].name, t2);
> - else printf("%s %s %s\n", toybuf, rrt[type].msg, t2);
> }
> }
> -
> if (CFG_TOYBOX_FREE) free(abuf);
> +}
> +
> +void host_main(void)
> +{
> + int verbose = FLAG(a)||FLAG(v), t2len=2048, type,rcode,i=0;
> + unsigned ttl;
> + char *t2 = toybuf+t2len;
> + // Grab nameservers
> + if (toys.optargs[1]) TT.nsname = toys.optargs+1;
> + else do_lines(xopen("/etc/resolv.conf", O_RDONLY), '\n', get_nsname);
> + if (!TT.nsname) error_exit("No nameservers");
> + if (verbose) printf("Using domain server %s:\n", *TT.nsname);
> + lookup(verbose,&ttl,t2,t2len,&type,&rcode);
> + for (i = 0; rrt[i].type != type; i++);
> + if (verbose) printf("%s\t%u\tIN %s\t%s\n", toybuf, ttl, rrt[i].name,
> t2);
> + else printf("%s %s %s\n", toybuf, rrt[type].msg, t2);
> + toys.exitval = rcode;
> +}
> +
> +#define FOR_nslookup
> +#include "generated/flags.h"
> +
> +void nslookup_main(void){
> + int t2len=2048, type,rcode;
> + unsigned ttl;
> + char *t2 = toybuf+t2len;
> + if (toys.optargs[1]) TT.nsname = toys.optargs+1;
> + else do_lines(xopen("/etc/resolv.conf", O_RDONLY), '\n', get_nsname);
> + if (!TT.nsname) error_exit("No nameservers");
> + printf("Server:\t %s:\nAddress: %s#53\n\n", *TT.nsname,
> *TT.nsname);//TODO:Not sure if static port is a good idea here
> + lookup(0,&ttl,t2,t2len,&type,&rcode);
> + printf("Non-authorative answer:\nName: %s\nAddress: %s\n", toybuf,
> t2);//TODO: Autherative answers
> toys.exitval = rcode;
> }
> --
> 2.20.1
>
>
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