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Add support for arbitrary prefix lengths in --rev-server and --domain=....,local

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Previously, the prefix was limited to [8,16,24,32] for IPv4 and
to multiples of 4 for IPv6. This patch also makes the prefix-length optional
for --rev-server.

Inspired by a patch from DL6ER <dl6er@dl6er.de>, but completely
re-written by srk. All bugs are his.
This commit is contained in:
Simon Kelley
2021-09-20 00:05:42 +01:00
parent de372d6914
commit 35f93081dc
3 changed files with 140 additions and 72 deletions
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3
src/network.c
View File

@@ -1586,6 +1586,9 @@ void check_servers(int no_loop_check)
if (serv->sfd)
serv->sfd->used = 1;
if (count == SERVERS_LOGGED)
my_syslog(LOG_INFO, _("more servers are defined but not logged"));
if (++count > SERVERS_LOGGED)
continue;

205
src/option.c
View File

@@ -935,52 +935,132 @@ char *parse_server(char *arg, union mysockaddr *addr, union mysockaddr *source_a
return NULL;
}
static int domain_rev4(char *domain, struct in_addr addr, int msize)
static char *domain_rev4(int from_file, char *server, struct in_addr *addr4, int size)
{
in_addr_t a = ntohl(addr.s_addr);
*domain = 0;
int i, j;
char *string;
int msize;
u16 flags = 0;
char domain[29]; /* strlen("xxx.yyy.zzz.ttt.in-addr.arpa")+1 */
union mysockaddr serv_addr, source_addr;
char interface[IF_NAMESIZE+1];
int count = 1, rem, addrbytes, addrbits;
switch (msize)
{
case 32:
domain += sprintf(domain, "%u.", a & 0xff);
/* fall through */
case 24:
domain += sprintf(domain, "%d.", (a >> 8) & 0xff);
/* fall through */
case 16:
domain += sprintf(domain, "%d.", (a >> 16) & 0xff);
/* fall through */
case 8:
domain += sprintf(domain, "%d.", (a >> 24) & 0xff);
if (!server)
flags = SERV_LITERAL_ADDRESS;
else if ((string = parse_server(server, &serv_addr, &source_addr, interface, &flags)))
return string;
if (from_file)
flags |= SERV_FROM_FILE;
rem = size & 0x7;
addrbytes = (32 - size) >> 3;
addrbits = (32 - size) & 7;
if (size > 32 | size < 1)
return _("bad IPv4 prefix length");
for (i = 0; i < addrbytes; i++)
if (((u8 *)addr4)[3-i] != 0)
break;
default:
return 0;
if (i != addrbytes || (((u8 *)addr4)[3-addrbytes] & ((1 << addrbits) - 1)) != 0)
return _("address part not zero");
size = size & ~0x7;
if (rem != 0)
count = 1 << (8 - rem);
for (i = 0; i < count; i++)
{
*domain = 0;
string = domain;
msize = size/8;
for (j = (rem == 0) ? msize-1 : msize; j >= 0; j--)
{
int dig = ((unsigned char *)addr4)[j];
if (j == msize)
dig += i;
string += sprintf(string, "%d.", dig);
}
sprintf(string, "in-addr.arpa");
if (!add_update_server(flags, &serv_addr, &source_addr, interface, domain, NULL))
return _("error");
}
sprintf(domain, "in-addr.arpa");
return 1;
return NULL;
}
static int domain_rev6(char *domain, struct in6_addr *addr, int msize)
static char *domain_rev6(int from_file, char *server, struct in6_addr *addr6, int size)
{
int i;
int i, j;
char *string;
int msize;
u16 flags = 0;
char domain[73]; /* strlen("32*<n.>ip6.arpa")+1 */
union mysockaddr serv_addr, source_addr;
char interface[IF_NAMESIZE+1];
int count = 1, rem, addrbytes, addrbits;
if (msize > 128 || msize%4)
return 0;
if (!server)
flags = SERV_LITERAL_ADDRESS;
else if ((string = parse_server(server, &serv_addr, &source_addr, interface, &flags)))
return string;
if (from_file)
flags |= SERV_FROM_FILE;
*domain = 0;
rem = size & 0x3;
addrbytes = (128 - size) >> 3;
addrbits = (128 - size) & 7;
if (size > 128 || size < 1)
return _("bad IPv6 prefix length");
for (i = msize-1; i >= 0; i -= 4)
{
int dig = ((unsigned char *)addr)[i>>3];
domain += sprintf(domain, "%.1x.", (i>>2) & 1 ? dig & 15 : dig >> 4);
for (i = 0; i < addrbytes; i++)
if (addr6->s6_addr[15-i] != 0)
break;
if (i != addrbytes || (addr6->s6_addr[15-addrbytes] & ((1 << addrbits) - 1)) != 0)
return _("address part not zero");
size = size & ~0x3;
if (rem != 0)
count = 1 << (4 - rem);
for (i = 0; i < count; i++)
{
*domain = 0;
string = domain;
msize = size/4;
for (j = (rem == 0) ? msize-1 : msize; j >= 0; j--)
{
int dig = ((unsigned char *)addr6)[j>>1];
dig = j & 1 ? dig & 15 : dig >> 4;
if (j == msize)
dig += i;
string += sprintf(string, "%.1x.", dig);
}
sprintf(string, "ip6.arpa");
if (!add_update_server(flags, &serv_addr, &source_addr, interface, domain, NULL))
return _("error");
}
sprintf(domain, "ip6.arpa");
return 1;
return NULL;
}
#ifdef HAVE_DHCP
@@ -2308,17 +2388,13 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
strlen(new->prefix) > MAXLABEL - INET_ADDRSTRLEN)
ret_err_free(_("bad prefix"), new);
}
else if (strcmp(arg, "local") != 0 ||
(msize != 8 && msize != 16 && msize != 24))
else if (strcmp(arg, "local") != 0)
ret_err_free(gen_err, new);
else
{
char domain[29]; /* strlen("xxx.yyy.zzz.ttt.in-addr.arpa")+1 */
/* local=/xxx.yyy.zzz.in-addr.arpa/ */
/* domain_rev4 can't fail here, msize checked above. */
domain_rev4(domain, new->start, msize);
add_update_server(SERV_LITERAL_ADDRESS, NULL, NULL, NULL, domain, NULL);
domain_rev4(0, NULL, &new->start, msize);
/* local=/<domain>/ */
/* d_raw can't failed to canonicalise here, checked above. */
add_update_server(SERV_LITERAL_ADDRESS, NULL, NULL, NULL, d_raw, NULL);
@@ -2353,16 +2429,14 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
strlen(new->prefix) > MAXLABEL - INET6_ADDRSTRLEN)
ret_err_free(_("bad prefix"), new);
}
else if (strcmp(arg, "local") != 0 || ((msize & 4) != 0))
else if (strcmp(arg, "local") != 0)
ret_err_free(gen_err, new);
else
{
char domain[73]; /* strlen("32*<n.>ip6.arpa")+1 */
/* generate the equivalent of
local=/xxx.yyy.zzz.ip6.arpa/ */
domain_rev6(domain, &new->start6, msize);
add_update_server(SERV_LITERAL_ADDRESS, NULL, NULL, NULL, domain, NULL);
domain_rev6(0, NULL, &new->start6, msize);
/* local=/<domain>/ */
/* d_raw can't failed to canonicalise here, checked above. */
add_update_server(SERV_LITERAL_ADDRESS, NULL, NULL, NULL, d_raw, NULL);
@@ -2735,46 +2809,37 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
{
char *string;
int size;
u16 flags = 0;
char domain[73]; /* strlen("32*<n.>ip6.arpa")+1 */
struct in_addr addr4;
struct in6_addr addr6;
union mysockaddr serv_addr, source_addr;
char interface[IF_NAMESIZE+1];
unhide_metas(arg);
if (!arg)
ret_err(gen_err);
comma=split(arg);
if (!(string = split_chr(arg, '/')) || !atoi_check(string, &size))
ret_err(gen_err);
if (!(string = split_chr(arg, '/')) || !atoi_check(string, &size))
size = -1;
if (inet_pton(AF_INET, arg, &addr4))
{
if (!domain_rev4(domain, addr4, size))
ret_err(_("bad IPv4 prefix"));
if (size == -1)
size = 32;
if ((string = domain_rev4(servers_only, comma, &addr4, size)))
ret_err(string);
}
else if (inet_pton(AF_INET6, arg, &addr6))
{
if (!domain_rev6(domain, &addr6, size))
ret_err(_("bad IPv6 prefix"));
if (size == -1)
size = 128;
if ((string = domain_rev6(servers_only, comma, &addr6, size)))
ret_err(string);
}
else
ret_err(gen_err);
if (!comma)
flags |= SERV_LITERAL_ADDRESS;
else if ((string = parse_server(comma, &serv_addr, &source_addr, interface, &flags)))
ret_err(string);
if (servers_only)
flags |= SERV_FROM_FILE;
if (!add_update_server(flags, &serv_addr, &source_addr, interface, domain, NULL))
ret_err(gen_err);
break;
}