mirror of
https://git.tartarus.org/simon/putty.git
synced 2025-01-25 01:02:24 +00:00
Reorganise sk_namelookup (on both platforms).
I just tried to trace through the Windows version's control flow in response to a confusing bug report, and found that the control flow itself was so confusing I couldn't make sense of it. Why are we choosing between getaddrinfo and gethostbyname via #ifndef NO_IPV6, then re-converging control flow and diverging a second time to report the error? So I rewrote the whole thing to have completely separate sections of code dealing with the three resolution strategies, each with its own dedicated error reporting system. And then I checked the Unix version and found it was about as confusing, so I rewrote that too in the same style. Now the two are mostly the same, except for details: Unix has an override at the top for a Unix socket pathname, Windows has to cope with getaddrinfo maybe not being found at run time (so the other cases aren't in the #else clause), and Windows uses the same error reporting for both lookup functions whereas Unix has to use the appropriate gai_strerror or hstrerror.
This commit is contained in:
Simon Tatham
parent
67204ffd0b
commit
e22df74545
154
unix/network.c
154
unix/network.c
@ -184,103 +184,89 @@ void sk_cleanup(void)
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}
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}
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SockAddr *sk_namelookup(const char *host, char **canonicalname, int address_family)
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SockAddr *sk_namelookup(const char *host, char **canonicalname,
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int address_family)
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{
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*canonicalname = NULL;
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if (host[0] == '/') {
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*canonicalname = dupstr(host);
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return unix_sock_addr(host);
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}
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SockAddr *ret = snew(SockAddr);
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#ifndef NO_IPV6
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struct addrinfo hints;
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int err;
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#else
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unsigned long a;
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struct hostent *h = NULL;
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int n;
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#endif
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strbuf *realhost = strbuf_new();
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/* Clear the structure and default to IPv4. */
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memset(ret, 0, sizeof(SockAddr));
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ret->superfamily = UNRESOLVED;
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ret->error = NULL;
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ret->refcount = 1;
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SockAddr *addr = snew(SockAddr);
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memset(addr, 0, sizeof(SockAddr));
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addr->superfamily = UNRESOLVED;
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addr->refcount = 1;
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#ifndef NO_IPV6
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hints.ai_flags = AI_CANONNAME;
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hints.ai_family = (address_family == ADDRTYPE_IPV4 ? AF_INET :
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address_family == ADDRTYPE_IPV6 ? AF_INET6 :
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AF_UNSPEC);
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hints.ai_socktype = SOCK_STREAM;
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hints.ai_protocol = 0;
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hints.ai_addrlen = 0;
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hints.ai_addr = NULL;
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hints.ai_canonname = NULL;
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hints.ai_next = NULL;
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/*
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* Use getaddrinfo, as long as it's available. This should handle
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* both IPv4 and IPv6 address literals, and hostnames, in one
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* unified API.
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*/
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{
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char *trimmed_host = host_strduptrim(host); /* strip [] on literals */
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err = getaddrinfo(trimmed_host, NULL, &hints, &ret->ais);
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sfree(trimmed_host);
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}
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if (err != 0) {
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ret->error = gai_strerror(err);
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strbuf_free(realhost);
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return ret;
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}
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ret->superfamily = IP;
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struct addrinfo hints;
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memset(&hints, 0, sizeof(hints));
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hints.ai_family = (address_family == ADDRTYPE_IPV4 ? AF_INET :
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address_family == ADDRTYPE_IPV6 ? AF_INET6 :
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AF_UNSPEC);
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hints.ai_flags = AI_CANONNAME;
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hints.ai_socktype = SOCK_STREAM;
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if (ret->ais->ai_canonname != NULL)
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put_fmt(realhost, "%s", ret->ais->ai_canonname);
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else
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put_fmt(realhost, "%s", host);
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#else
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if ((a = inet_addr(host)) == (unsigned long)(in_addr_t)(-1)) {
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/*
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* Otherwise use the IPv4-only gethostbyname... (NOTE:
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* we don't use gethostbyname as a fallback!)
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*/
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if (ret->superfamily == UNRESOLVED) {
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/*debug("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host); */
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if ( (h = gethostbyname(host)) )
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ret->superfamily = IP;
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/* strip [] on IPv6 address literals */
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char *trimmed_host = host_strduptrim(host);
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int err = getaddrinfo(trimmed_host, NULL, &hints, &addr->ais);
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sfree(trimmed_host);
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if (addr->ais) {
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addr->superfamily = IP;
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if (addr->ais->ai_canonname)
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*canonicalname = dupstr(addr->ais->ai_canonname);
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else
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*canonicalname = dupstr(host);
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} else {
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addr->error = gai_strerror(err);
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}
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if (ret->superfamily == UNRESOLVED) {
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ret->error = (h_errno == HOST_NOT_FOUND ||
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h_errno == NO_DATA ||
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h_errno == NO_ADDRESS ? "Host does not exist" :
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h_errno == TRY_AGAIN ?
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"Temporary name service failure" :
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"gethostbyname: unknown error");
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strbuf_free(realhost);
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return ret;
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}
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/* This way we are always sure the h->h_name is valid :) */
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strbuf_clear(realhost);
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put_fmt(realhost, "%s", h->h_name);
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for (n = 0; h->h_addr_list[n]; n++);
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ret->addresses = snewn(n, unsigned long);
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ret->naddresses = n;
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for (n = 0; n < ret->naddresses; n++) {
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memcpy(&a, h->h_addr_list[n], sizeof(a));
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ret->addresses[n] = ntohl(a);
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}
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} else {
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/*
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* This must be a numeric IPv4 address because it caused a
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* success return from inet_addr.
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*/
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ret->superfamily = IP;
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strbuf_clear(realhost);
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put_fmt(realhost, "%s", host);
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ret->addresses = snew(unsigned long);
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ret->naddresses = 1;
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ret->addresses[0] = ntohl(a);
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return addr;
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}
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#else
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/*
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* Failing that (if IPv6 support was not compiled in), try the
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* old-fashioned approach, which is to start by manually checking
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* for an IPv4 literal and then use gethostbyname.
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*/
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unsigned long a = inet_addr(host);
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if (a != (unsigned long) INADDR_NONE) {
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addr->addresses = snew(unsigned long);
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addr->naddresses = 1;
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addr->addresses[0] = ntohl(a);
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addr->superfamily = IP;
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*canonicalname = dupstr(host);
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return addr;
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}
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struct hostent *h = gethostbyname(host);
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if (h) {
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addr->superfamily = IP;
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size_t n;
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for (n = 0; h->h_addr_list[n]; n++);
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addr->addresses = snewn(n, unsigned long);
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addr->naddresses = n;
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for (n = 0; n < addr->naddresses; n++) {
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uint32_t a;
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memcpy(&a, h->h_addr_list[n], sizeof(a));
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addr->addresses[n] = ntohl(a);
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}
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*canonicalname = dupstr(h->h_name);
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} else {
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addr->error = hstrerror(h_errno);
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}
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return addr;
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#endif
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*canonicalname = strbuf_to_str(realhost);
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return ret;
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}
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SockAddr *sk_nonamelookup(const char *host)
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@ -452,118 +452,95 @@ const char *winsock_error_string(int error)
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return win_strerror(error);
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}
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static inline const char *namelookup_strerror(DWORD err)
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{
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/* PuTTY has traditionally translated a few of the likely error
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* messages into more concise strings than the standard Windows ones */
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return (err == WSAENETDOWN ? "Network is down" :
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err == WSAHOST_NOT_FOUND ? "Host does not exist" :
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err == WSATRY_AGAIN ? "Host not found" :
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win_strerror(err));
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}
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SockAddr *sk_namelookup(const char *host, char **canonicalname,
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int address_family)
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{
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SockAddr *ret = snew(SockAddr);
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unsigned long a;
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char realhost[8192];
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int hint_family;
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*canonicalname = NULL;
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/* Default to IPv4. */
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hint_family = (address_family == ADDRTYPE_IPV4 ? AF_INET :
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#ifndef NO_IPV6
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address_family == ADDRTYPE_IPV6 ? AF_INET6 :
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#endif
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AF_UNSPEC);
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SockAddr *addr = snew(SockAddr);
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memset(addr, 0, sizeof(SockAddr));
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addr->superfamily = UNRESOLVED;
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addr->refcount = 1;
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/* Clear the structure and default to IPv4. */
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memset(ret, 0, sizeof(SockAddr));
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#ifndef NO_IPV6
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ret->ais = NULL;
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#endif
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ret->addresses = NULL;
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ret->superfamily = UNRESOLVED;
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ret->refcount = 1;
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*realhost = '\0';
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/*
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* Use getaddrinfo, as long as it's available. This should handle
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* both IPv4 and IPv6 address literals, and hostnames, in one
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* unified API.
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*/
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if (p_getaddrinfo) {
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struct addrinfo hints;
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memset(&hints, 0, sizeof(hints));
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hints.ai_family = (address_family == ADDRTYPE_IPV4 ? AF_INET :
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address_family == ADDRTYPE_IPV6 ? AF_INET6 :
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AF_UNSPEC);
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hints.ai_flags = AI_CANONNAME;
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hints.ai_socktype = SOCK_STREAM;
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if ((a = p_inet_addr(host)) == (unsigned long) INADDR_NONE) {
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struct hostent *h = NULL;
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int err = 0;
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#ifndef NO_IPV6
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/*
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* Use getaddrinfo when it's available
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*/
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if (p_getaddrinfo) {
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struct addrinfo hints;
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memset(&hints, 0, sizeof(hints));
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hints.ai_family = hint_family;
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hints.ai_flags = AI_CANONNAME;
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{
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/* strip [] on IPv6 address literals */
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char *trimmed_host = host_strduptrim(host);
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err = p_getaddrinfo(trimmed_host, NULL, &hints, &ret->ais);
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sfree(trimmed_host);
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}
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if (err == 0)
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ret->superfamily = IP;
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} else
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#endif
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{
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/*
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* Otherwise use the IPv4-only gethostbyname...
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* (NOTE: we don't use gethostbyname as a fallback!)
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*/
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if ( (h = p_gethostbyname(host)) )
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ret->superfamily = IP;
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/* strip [] on IPv6 address literals */
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char *trimmed_host = host_strduptrim(host);
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int err = p_getaddrinfo(trimmed_host, NULL, &hints, &addr->ais);
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sfree(trimmed_host);
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if (addr->ais) {
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addr->superfamily = IP;
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if (addr->ais->ai_canonname)
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*canonicalname = dupstr(addr->ais->ai_canonname);
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else
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err = p_WSAGetLastError();
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}
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if (ret->superfamily != IP) {
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ret->error = (err == WSAENETDOWN ? "Network is down" :
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err == WSAHOST_NOT_FOUND ? "Host does not exist" :
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err == WSATRY_AGAIN ? "Host not found" :
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win_strerror(err));
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*canonicalname = dupstr(host);
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} else {
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ret->error = NULL;
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#ifndef NO_IPV6
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/* If we got an address info use that... */
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if (ret->ais) {
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/* Are we in IPv4 fallback mode? */
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/* We put the IPv4 address into the a variable so we can further-on use the IPv4 code... */
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if (ret->ais->ai_family == AF_INET)
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memcpy(&a,
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(char *) &((SOCKADDR_IN *) ret->ais->
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ai_addr)->sin_addr, sizeof(a));
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if (ret->ais->ai_canonname)
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strncpy(realhost, ret->ais->ai_canonname, lenof(realhost));
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else
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strncpy(realhost, host, lenof(realhost));
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}
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/* We used the IPv4-only gethostbyname()... */
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else
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#endif
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{
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int n;
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for (n = 0; h->h_addr_list[n]; n++);
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ret->addresses = snewn(n, unsigned long);
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ret->naddresses = n;
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for (n = 0; n < ret->naddresses; n++) {
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memcpy(&a, h->h_addr_list[n], sizeof(a));
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ret->addresses[n] = p_ntohl(a);
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}
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memcpy(&a, h->h_addr, sizeof(a));
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/* This way we are always sure the h->h_name is valid :) */
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strncpy(realhost, h->h_name, sizeof(realhost));
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}
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addr->error = namelookup_strerror(err);
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}
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} else {
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/*
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* This must be a numeric IPv4 address because it caused a
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* success return from inet_addr.
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*/
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ret->addresses = snewn(1, unsigned long);
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ret->naddresses = 1;
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ret->addresses[0] = p_ntohl(a);
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ret->superfamily = IP;
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strncpy(realhost, host, sizeof(realhost));
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return addr;
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}
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realhost[lenof(realhost)-1] = '\0';
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*canonicalname = dupstr(realhost);
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return ret;
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#endif
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/*
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* Failing that (if IPv6 support was not compiled in, or if
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* getaddrinfo turned out to be unavailable at run time), try the
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* old-fashioned approach, which is to start by manually checking
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* for an IPv4 literal and then use gethostbyname.
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*/
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unsigned long a = p_inet_addr(host);
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if (a != (unsigned long) INADDR_NONE) {
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addr->addresses = snew(unsigned long);
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addr->naddresses = 1;
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addr->addresses[0] = p_ntohl(a);
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addr->superfamily = IP;
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*canonicalname = dupstr(host);
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return addr;
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}
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struct hostent *h = p_gethostbyname(host);
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if (h) {
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addr->superfamily = IP;
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size_t n;
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for (n = 0; h->h_addr_list[n]; n++);
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addr->addresses = snewn(n, unsigned long);
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addr->naddresses = n;
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for (n = 0; n < addr->naddresses; n++) {
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uint32_t a;
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memcpy(&a, h->h_addr_list[n], sizeof(a));
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addr->addresses[n] = p_ntohl(a);
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}
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*canonicalname = dupstr(h->h_name);
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} else {
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DWORD err = p_WSAGetLastError();
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addr->error = namelookup_strerror(err);
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}
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return addr;
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}
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static SockAddr *sk_special_addr(SuperFamily superfamily, const char *name)
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Block a user