version 1.1.1.2, 2021/03/17 00:56:46
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version 1.1.1.3, 2023/09/27 11:02:07
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/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley | /* dnsmasq is Copyright (c) 2000-2022 Simon Kelley |
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This program is free software; you can redistribute it and/or modify |
This program is free software; you can redistribute it and/or modify |
it under the terms of the GNU General Public License as published by |
it under the terms of the GNU General Public License as published by |
Line 22 static ssize_t loop_make_probe(u32 uid);
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Line 22 static ssize_t loop_make_probe(u32 uid);
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void loop_send_probes() |
void loop_send_probes() |
{ |
{ |
struct server *serv; |
struct server *serv; |
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struct randfd_list *rfds = NULL; |
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if (!option_bool(OPT_LOOP_DETECT)) |
if (!option_bool(OPT_LOOP_DETECT)) |
return; |
return; |
Line 29 void loop_send_probes()
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Line 30 void loop_send_probes()
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/* Loop through all upstream servers not for particular domains, and send a query to that server which is |
/* Loop through all upstream servers not for particular domains, and send a query to that server which is |
identifiable, via the uid. If we see that query back again, then the server is looping, and we should not use it. */ |
identifiable, via the uid. If we see that query back again, then the server is looping, and we should not use it. */ |
for (serv = daemon->servers; serv; serv = serv->next) |
for (serv = daemon->servers; serv; serv = serv->next) |
if (!(serv->flags & | if (strlen(serv->domain) == 0 && |
(SERV_LITERAL_ADDRESS | SERV_NO_ADDR | SERV_USE_RESOLV | SERV_NO_REBIND | SERV_HAS_DOMAIN | SERV_FOR_NODOTS | SERV_LOOP))) | !(serv->flags & (SERV_FOR_NODOTS))) |
{ |
{ |
ssize_t len = loop_make_probe(serv->uid); |
ssize_t len = loop_make_probe(serv->uid); |
int fd; |
int fd; |
struct randfd *rfd = NULL; |
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if (serv->sfd) | serv->flags &= ~SERV_LOOP; |
fd = serv->sfd->fd; | |
else | |
{ | |
if (!(rfd = allocate_rfd(serv->addr.sa.sa_family))) | |
continue; | |
fd = rfd->fd; | |
} | |
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if ((fd = allocate_rfd(&rfds, serv)) == -1) |
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continue; |
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while (retry_send(sendto(fd, daemon->packet, len, 0, |
while (retry_send(sendto(fd, daemon->packet, len, 0, |
&serv->addr.sa, sa_len(&serv->addr)))); |
&serv->addr.sa, sa_len(&serv->addr)))); |
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free_rfd(rfd); |
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} |
} |
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free_rfds(&rfds); |
} |
} |
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static ssize_t loop_make_probe(u32 uid) |
static ssize_t loop_make_probe(u32 uid) |
{ |
{ |
struct dns_header *header = (struct dns_header *)daemon->packet; |
struct dns_header *header = (struct dns_header *)daemon->packet; |
unsigned char *p = (unsigned char *)(header+1); |
unsigned char *p = (unsigned char *)(header+1); |
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/* packet buffer overwritten */ |
/* packet buffer overwritten */ |
daemon->srv_save = NULL; |
daemon->srv_save = NULL; |
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Line 96 int detect_loop(char *query, int type)
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Line 92 int detect_loop(char *query, int type)
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return 0; |
return 0; |
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for (i = 0; i < 8; i++) |
for (i = 0; i < 8; i++) |
if (!isxdigit(query[i])) | if (!isxdigit((unsigned char)query[i])) |
return 0; |
return 0; |
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uid = strtol(query, NULL, 16); |
uid = strtol(query, NULL, 16); |
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for (serv = daemon->servers; serv; serv = serv->next) |
for (serv = daemon->servers; serv; serv = serv->next) |
if (!(serv->flags & | if (strlen(serv->domain) == 0 && |
(SERV_LITERAL_ADDRESS | SERV_NO_ADDR | SERV_USE_RESOLV | SERV_NO_REBIND | SERV_HAS_DOMAIN | SERV_FOR_NODOTS | SERV_LOOP)) && | !(serv->flags & SERV_LOOP) && |
uid == serv->uid) | uid == serv->uid) |
{ | { |
serv->flags |= SERV_LOOP; | serv->flags |= SERV_LOOP; |
check_servers(); /* log new state */ | check_servers(1); /* log new state - don't send more probes. */ |
return 1; | return 1; |
} | } |
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return 0; |
return 0; |
} |
} |
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