dns: add a comment about case insensitivity

introduce 'lwip_tolower' and use it in dns.c

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

fix DNS resolution to not case insensitivity

See patch #9654

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

dns_compare_name: change check for u16_t overflow

check upper border (0xFFFF) instead of checking for 0 after overflow

Minor DNS documentation improvement

dns: Use dns_backupserver_available() instead of open-coded

Slightly better readability by calling dns_backupserver_available()
instead of open-coded. Also move dns_backupserver_available() function
up to avoid forward declaration.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: goldsimon <goldsimon@gmx.de>

Move DNS_MAX_RETRIES option from dns.c to opt.h

Fix bug #52239: if a DNS request is denied by a DNS server, this DNS request shouldn't be stopped if there is another DNS server to try
Apply improved version of Xiaodong Sun's patch

dns.c: Rename goto label memerr to ignore_packet
Label is more descriptive this way

Reformat core code using astylerc

Add @todo: scope ip6addr?

Correct a few uses of sizeof(ip6_addr_t) to sizeof(ip6_addr_p_t)

The ip6_addr_t structure may have an addition slot so is not necessarily
the size of an ipv6 address, so some uses of sizeof(ip6_addr_t) were not
correct.

Signed-off-by: goldsimon <goldsimon@gmx.de>

DNS_MAX_SOURCE_PORTS is PP-checked to be <= 255...

work on -Wconversion...

Use ip_addr_debug_print_val instead of ip_addr_debug_print where applicable

Improved DNS_LOCAL_HOSTLIST interface (bug #50325)

dns: Slightly improve dns_alloc_random_port implementation

Having the variable namining ret for a pointer makes the code looks odd,
ret looks like a value variable. Rename ret to pcb.
Also simplify the code in the do {} while() loop.

Signed-off-by: Axel Lin <axel.lin@ingics.com>

dns: Clean up unneeded #if guard for DNS_LOCAL_HOSTLIST/DNS_LOOKUP_LOCAL_EXTERN

This is a leftover of commit e77e18f8c410 "Worked on IPv6-only stack", fix it.

Signed-off-by: Axel Lin <axel.lin@ingics.com>

dns: added one-shot multicast DNS queries

DNS: added compile-time check for some defines to fit into an u8_t (bug #49658)

Fix compile when IPv4 is disabled

dns_enqueue(): minor readability improvement: add local variable "age" to store result of subtraction

Make lwIP compile with clang -Wdocumentation -> several documentation fixes

Cleanup hton*/ntoh* function handling and platform abstraction
Let lwip use functions/macros prefixed by lwip_ internally to avoid naming clashes with external #includes.
Remove over-complicated #define handling in def.h
Make functions easier to override in cc.h. The following is sufficient now (no more LWIP_PLATFORM_BYTESWAP):
#define lwip_htons(x) <your_htons>
#define lwip_htonl(x) <your_htonl>

Cleanup handling of non-standard functions in lwIP
- itoa
- strnicmp, stricmp/strcasecmp
- strnstr
Related to patch #9115: httpd.c: strcasecmp for GCC and stricmp for Windows

Implement consistent IPx_ADDR_ANYx macro naming between IPv4 and IPv6
- rename IP4_ADDR_ANY to IP4_ADDR_ANY4
- IP4_ADDR_ANY (= IP_ADDR_ANY) is now IPv4 any address in ip_addr_t format

dns: Drop unnecessary txid variable in dns_check_entry

Signed-off-by: Axel Lin <axel.lin@ingics.com>

added more out of range checks to dns_recv() (see bug #48924)

Fix bug #48924: Potential out of bound reads in DNS codes of lwip project by adding checks for pbuf_copy_partial() return values.
Add some comments to clarify handling of untrusted network data handling.

moved 2 enums from 'prot' headers to where they belong (dns, dhcp)

Minor: Documentation fixes

Move DNS protocol structs to separate header. Needed for Erik Ekman's MDNS implementation.

Work on bug #48730: Enums should be used instead of multiple defines (where applicable)

Work on lwIP documentation

Restructure documentation. Create two top-level sections for thread-safe and callback-style APIs.

Document netif API in doxygen module style

Document DNS, memory pools and PBUFs as modules

dns: fixed declaration and usage of DNS_LOOKUP_LOCAL_EXTERN()

fixed bug #48398 (dns: entries reused during found-callback could be aborted if ttl==0)

Fix bug #48359 (dns entries are not set to state DONE)

Fix dns_getserver to return a pointer, not a value

Fix several doxygen errors all over the code

dns: Use LWIP_ARRAYSIZE instead of open coded

Signed-off-by: Axel Lin <axel.lin@ingics.com>

Create new IP_IS_V4 macros and use them at instead of !IP_IS_V6 - since we now have an IPADDR_ANY_TYPE, just checking for !V6 does not mean it is V4

ignore dns response parsing errors, only abort resolving for correct responses or error responses from correct server (bug #47459)

Fix bug #47370: Port DNS client to IPv6

dns_gethostbyname: return error code if no valid server is set instead of calling the 'found' callback in this case (fixes bug #46887)

DNS: Fix potential array out of bounds access. Variable nanswers may contain bogus values. (found by Coverity)

Apply patch #8854: dns: Simplify #ifdef guard around dns_gethostbyname_addrtype from Axel Lin
+ Minor compile fix from me
Patch makes the code a tiny bit less lightweight (add a parameter in dns_gethostbyname which is then not used in dns_gethostbyname_addrtype) but it makes the code more readable.

dns: Remove always true test in dns_alloc_random_port

The only way to exit the do-while loop is err != ERR_USE.
Thus get rid of the always true test.

Signed-off-by: Axel Lin <axel.lin@ingics.com>

dns: Fix dns_alloc_pcb for reuse an existing one case

The logic to use an already existing pcb is wrong because the idx never
advanced in the for loop, so it keep checking the same dns_pcbs[idx] for
each loop iteration. Fix it.

Signed-off-by: Axel Lin <axel.lin@ingics.com>

minor: fixed coding style (lwip style)

minor: coding style

Make LWIP_DNS_SECURE and its possible values known in opt.h, remove default initialization of DNS server

minor: removed superfluous comma after '}' in dns.c

dns: improved handling 2nd server if first failed

Fixed bug #46071 Logic error in line 1473 in dns.c

fixed compiler warnings where passing variable instance to ip_addr_isany

fixed compiler warnings reported by mingw-64

fixed constness for DNS_LOCAL_HOSTLIST_IS_DYNAMIC

Compiler warning fixes (mostly constness in dual-stack configurations)

minor compiler warning fixes and coding style

Fix typos from task #12243

This fixes two typos spotted during visual inspection of changes related
to task #12243

fixed compiling DNS code again

Changed dns_gethostbyname_addrtype() to always be a function, fixed code for C PP :-(

fixed unused variable warning

dns: fixed trivial compiler warning

lwip/src/core/dns.c:1471:8: warning: extra tokens at end of #endif directive [-Wendif-labels]
#endif LWIP_IPV4 && LWIP_IPV6

worked on task #12243 (Add support for AAAA/IPv6 records to DNS)

task #12243: DNS/IPv6: added support for AAAA records

- prework for fixing bug #45029: access IPv4 configuration of struct netif via new API (netif_ip4_addr()/netif_ip4_netmask()/netif_ip4_gw()) instead of accessing the struct member directly. This way, we can change the struct member types from ip4_addr_t to ip_addr_t;
- fixed some bugs in calls to ip4_addr*() where the cast to u8_t* did not reveal the wrong address type

dns.c: fixed compiler warning

fixed bug #45004: dns response without answer might be discarded

accidentally committed debug comment //

dns: fixed assertion when dns server address is set to ANY (patch #8692)

added more missing casts

fixed some more missing casts...

Worked on IPv6-only stack:
- prepared DNS;
- fixed compiling ppp.c

task #12722 (improve IPv4/v6 address handling): renamed ip_addr_t to ip4_addr_t, renamed ipX_addr_t to ip_addr_t and added IP version;
ip_addr_t is used for all generic IP addresses for the API, ip(4/6)_addr_t are only used internally or when initializing netifs or when calling version-related functions

DNS, warning fix, dns_init() -> dns_init(void)

lwip/src/core/dns.c: In function ‘dns_init’:
lwip/src/core/dns.c:336:1: warning: old-style function definition [-Wold-style-definition]
dns_init()

Continued chrysn's work: changed nearly all functions taking 'ip(X)_addr_t' pointer to take const pointers (changed user callbacks: raw_recv_fn, udp_recv_fn; changed port callbacks: netif_output_fn, netif_igmp_mac_filter_fn)

fixed bug #43389 dns_recv() res_idx calculate error

Parts of patch #8397 Typos corrected in comments and text outputs

patch #8480 Fix handling of dns_seqno wraparound

dns.c: change dns_send/dns_recv to operate on pbuf, not on contiguous buffer -> dns_payload_buffer/DNS_MSG_SIZE can be removed

added source port randomization to make the DNS client more robust (see bug #43144)

revert accidentally committed test code

DNS: minor coding style fix: pEntry -> entry

DNS: split request callback information from actual DNS table to be able to optimize memory usage for multiple parallel requests (and clean up the code a bit)

added optional macros PACK_STRUCT_FLD_8() and PACK_STRUCT_FLD_S() to prevent gcc 4 from warning about struct members that do not need packing

fixed bug #42987 lwIP is vulnerable to DNS cache poisoning due to non-randomized TXIDs

fixed bug #37705 Possible memory corruption in DNS query

fixed bug #37705 Possible memory corruption in DNS query

Fixed bug #36899 DNS TTL 0 is cached for a long time

Fixed bug #31701: Error return value from dns_gethostbyname() does not match documentation: return ERR_ARG instead of ERR_VAL if not initialized or wrong argument.

Added LWIP_DEBUGF warning if dns_send returns an error

Add preprocessor-macros for compile-time htonl calculation (and use them throughout the stack where applicable)

DNS_LOCAL_HOSTLIST_IS_DYNAMIC uses its own MEMP pool instead of the heap

Added missing casts, use strlen + MEMCPY instead of strcpy (as that might overrun the buffer)

Fixed compilation for DNS_LOCAL_HOSTLIST==1 and DNS_LOCAL_HOSTLIST_IS_DYNAMIC==1 (bug #28968)

task #10140: Remove DNS_USES_STATIC_BUF (keep the implementation of DNS_USES_STATIC_BUF==1)

Revert my last changes and remove structure packing from struct dns_query and struct dns_answer since they are only used with SMEMCPY

Use pointers instead of using SMEMCPY

Minor speedups: use ip_addr_copy, use SMEMCPY, use htonX on constants instead of variables

Don't use C++ reserved keyword 'class'

Minor: Fixed indentation after changing struct ip_addr to ip_addr_t

Minot: Fixed comments and code style

Replaced struct ip_addr by typedef ip_addr_t to make changing the actual implementation behind the typedef easier.

Use macros defined in ip_addr.h (some of them new) to work with IP addresses (preparation for bug #27352 - Change ip_addr from struct to typedef (u32_t) - and better code).

Fixed compiler warnings when MEM_SIZE < 64000

Cleanly separate the portability file inet.h and its contents from the stack: moved htonX- functions to def.h (and the new def.c - they are not ipv4 dependent), let inet.h depend on ip_addr.h and not the other way round. This fixes bug #28732.

bug #26523: Compiler Warnings

Copy hostname for DNS_LOCAL_HOSTLIST_IS_DYNAMIC==1 since string passed to dns_local_addhost() might be volatile

Fixed bug #26657: DNS, if host name is "localhost", result is error.

Corrected structure packing

Worked on dns: local host-list can be put into FLASH (by defining storage target/linker section), external function can be defined for lookup, combined dns_local_removehostname/removehostaddr to dns_local_removehost

Fixed some issues with DNS_LOCAL_HOSTLIST

task #7507, patch #6786: DNS supports static hosts table. New configuration options DNS_LOCAL_HOSTLIST and DNS_LOCAL_HOSTLIST_IS_DYNAMIC.

* dns.c: Hard-code structure sizes, to avoid issues on some compilers where
padding is included.

Minor changes: replace directy call to memcpy by MEMCPY macro.

dns.c: Fix bug #22108 "DNS problem" caused by unaligned structures.

Minor changes in lwip folder: fix some warnings, coding style, and rename "internal" netconn_alloc function.

api_msg.c, err.h, err.c, sockets.c, dns.c, dns.h: replace "enum dns_result" by err_t type. Add a new err_t code "ERR_INPROGRESS".

Minor change: move DNS_MSG_SIZE in opt.h, add comments.

dns.h, dns.c, opt.h: move DNS options to the "right" place. Most visibles are the ones which have ram usage.

process "localhost" name in dns_gethostbyname

Minor changes: dnsserver initialization with DNS_SERVER_ADDRESS in dns_init

connect the UDP pcb to the DNS server (IPaddress and port) to receive faster (unconnected pcbs are very inefficient in udp_input)

Minor change (doxygen tags)

Minor changes in DNS client.

Added function documentation to dns.c, removed function documentation from dns.h (functions should be documented where they are implemented!), dns_table_entry doesn't have to be packed (slower, bigger code for most machines), converted dns_init to return void, dns_table is implicitly initialized to zero, dns_lookup can be static, dns_send returns correct error values, added some asserts, compacted dns_recv using some (ugly) gotos, compacted dns_gethostbyname by combining the same return value

api_msg.c, dns.h, dns.c: Implement DNS_DOES_NAME_CHECK option (check if name received match the name query), implement DNS_USES_STATIC_BUF (the place where copy dns payload to parse the response), return an error if there is no place for a new query, and fix some minor problems.

Fix DNS client TTL processing.

Minor changes on DNS.

fix DNS problem with pbuf chain.

Changes on DNS client. Add multiples dns servers support.

Minor changes on DNS client. Coding style & add "response" checking

Minor changes on DNS client. Note that "compressed answers are fixed".

Minor changes on DNS client.

Turned all hostname variables and parameters into (const char*)

opt.h, init.c, tcpip.c, dhcp.c, dns.h, dns.c: add DNS client for simple name requests with RAW api interface. Initialization is done in lwip_init() with build time options. DNS timer is added in tcpip_thread context. DHCP can set DNS server ip addresses when options are received. You need to set LWIP_DNS=1 in your lwipopts.h file (LWIP_DNS=0 in opt.h). DNS_DEBUG can be set to get some traces with LWIP_DEBUGF. Sanity check have been added. There is a "todo" list with points to improve.