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From: Siddhesh Poyarekar <siddhesh@sourceware.org>
To: glibc-cvs@sourceware.org
Subject: [glibc/siddhesh/gai-cleanup2] gaih_inet: separate nss lookup loop into its own function
Date: Tue, 1 Mar 2022 02:41:12 +0000 (GMT) [thread overview]
Message-ID: <20220301024112.5DA323858408@sourceware.org> (raw)
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=98f728a01610bb31622c2ccff18795853dd849d1
commit 98f728a01610bb31622c2ccff18795853dd849d1
Author: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date: Mon Feb 28 20:20:41 2022 +0530
gaih_inet: separate nss lookup loop into its own function
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Diff:
---
sysdeps/posix/getaddrinfo.c | 529 +++++++++++++++++++++++---------------------
1 file changed, 274 insertions(+), 255 deletions(-)
diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c
index ea3fa76748..59109d0a35 100644
--- a/sysdeps/posix/getaddrinfo.c
+++ b/sysdeps/posix/getaddrinfo.c
@@ -297,7 +297,6 @@ convert_hostent_to_gaih_addrtuple (const struct addrinfo *req,
break; \
if (!scratch_buffer_grow (tmpbuf)) \
{ \
- __resolv_context_put (res_ctx); \
result = -EAI_MEMORY; \
goto free_and_return; \
} \
@@ -307,7 +306,6 @@ convert_hostent_to_gaih_addrtuple (const struct addrinfo *req,
{ \
if (h_errno == NETDB_INTERNAL) \
{ \
- __resolv_context_put (res_ctx); \
result = -EAI_SYSTEM; \
goto free_and_return; \
} \
@@ -321,11 +319,10 @@ convert_hostent_to_gaih_addrtuple (const struct addrinfo *req,
struct gaih_addrtuple *addrmem = NULL; \
if (!convert_hostent_to_gaih_addrtuple (req, _family, &th, &addrmem)) \
{ \
- __resolv_context_put (res_ctx); \
result = -EAI_SYSTEM; \
goto free_and_return; \
} \
- if (addrmem && !gaih_lookup_result_push_alloc (&res, addrmem)) \
+ if (addrmem && !gaih_lookup_result_push_alloc (res, addrmem)) \
{ \
free (addrmem); \
result = -EAI_MEMORY; \
@@ -339,14 +336,13 @@ convert_hostent_to_gaih_addrtuple (const struct addrinfo *req,
char *canonbuf = __strdup (localcanon); \
if (canonbuf == NULL) \
{ \
- __resolv_context_put (res_ctx); \
result = -EAI_SYSTEM; \
goto free_and_return; \
} \
canon = canonbuf; \
} \
if (_family == AF_INET6 && addrmem != NULL) \
- got_ipv6 = true; \
+ res->got_ipv6 = true; \
} \
}
@@ -768,6 +764,271 @@ simple_gethostbyname (const char *name, const struct addrinfo *req,
return -EAI_NODATA;
}
+static int
+get_nss_addresses (const char *name, const struct addrinfo *req,
+ struct scratch_buffer *tmpbuf,
+ struct gaih_lookup_result *res)
+{
+ struct gaih_addrtuple *at = NULL;
+
+ /* Use PAT to track the end of the tuple list so that multiple lookups append
+ to the end of the latest list. */
+ struct gaih_addrtuple **pat = &at;
+ int no_data = 0;
+ int no_inet6_data = 0;
+ nss_action_list nip;
+ enum nss_status inet6_status = NSS_STATUS_UNAVAIL;
+ enum nss_status status = NSS_STATUS_UNAVAIL;
+ int no_more;
+ struct resolv_context *res_ctx = NULL;
+ char *canon = NULL;
+ int result = 0;
+
+ res->at = NULL;
+
+ no_more = !__nss_database_get (nss_database_hosts, &nip);
+
+ /* If we are looking for both IPv4 and IPv6 address we don't
+ want the lookup functions to automatically promote IPv4
+ addresses to IPv6 addresses, so we use the no_inet6
+ function variant. */
+ res_ctx = __resolv_context_get ();
+ if (res_ctx == NULL)
+ no_more = 1;
+
+ while (!no_more)
+ {
+ no_data = 0;
+ nss_gethostbyname4_r *fct4 = NULL;
+
+ /* gethostbyname4_r sends out parallel A and AAAA queries and
+ is thus only suitable for PF_UNSPEC. */
+ if (req->ai_family == PF_UNSPEC)
+ fct4 = __nss_lookup_function (nip, "gethostbyname4_r");
+
+ if (fct4 != NULL)
+ {
+ size_t length = 1024;
+ char *buf = malloc (length);
+
+ while (1)
+ {
+ *pat = NULL;
+ status = DL_CALL_FCT (fct4, (name, pat, buf, length, &errno,
+ &h_errno, NULL));
+ if (status == NSS_STATUS_SUCCESS)
+ break;
+ if (status != NSS_STATUS_TRYAGAIN
+ || errno != ERANGE || h_errno != NETDB_INTERNAL)
+ {
+ if (h_errno == TRY_AGAIN)
+ no_data = EAI_AGAIN;
+ else
+ no_data = h_errno == NO_DATA;
+ break;
+ }
+
+ length *= 2;
+ free (buf);
+ if ((buf = malloc (length)) == NULL)
+ {
+ result = -EAI_MEMORY;
+ goto free_and_return;
+ }
+ }
+
+ if (!gaih_lookup_result_push_alloc (res, buf))
+ {
+ free (buf);
+ result = -EAI_MEMORY;
+ goto free_and_return;
+ }
+
+ if (status == NSS_STATUS_SUCCESS)
+ {
+ assert (!no_data);
+ no_data = 1;
+
+ if ((req->ai_flags & AI_CANONNAME) != 0 && canon == NULL)
+ {
+ char *canonbuf = __strdup ((*pat)->name);
+ if (canonbuf == NULL)
+ {
+ result = -EAI_MEMORY;
+ goto free_and_return;
+ }
+ canon = canonbuf;
+ }
+
+ while (*pat != NULL)
+ {
+ if ((*pat)->family == AF_INET && req->ai_family == AF_INET6
+ && (req->ai_flags & AI_V4MAPPED) != 0)
+ {
+ uint32_t *pataddr = (*pat)->addr;
+ (*pat)->family = AF_INET6;
+ pataddr[3] = pataddr[0];
+ pataddr[2] = htonl (0xffff);
+ pataddr[1] = 0;
+ pataddr[0] = 0;
+ pat = &((*pat)->next);
+ no_data = 0;
+ }
+ else if (req->ai_family == AF_UNSPEC
+ || (*pat)->family == req->ai_family)
+ {
+ pat = &((*pat)->next);
+
+ no_data = 0;
+ if (req->ai_family == AF_INET6)
+ res->got_ipv6 = true;
+ }
+ else
+ *pat = ((*pat)->next);
+ }
+ }
+
+ no_inet6_data = no_data;
+ }
+ else
+ {
+ nss_gethostbyname3_r *fct = NULL;
+ if (req->ai_flags & AI_CANONNAME)
+ /* No need to use this function if we do not look for
+ the canonical name. The function does not exist in
+ all NSS modules and therefore the lookup would
+ often fail. */
+ fct = __nss_lookup_function (nip, "gethostbyname3_r");
+ if (fct == NULL)
+ /* We are cheating here. The gethostbyname2_r
+ function does not have the same interface as
+ gethostbyname3_r but the extra arguments the
+ latter takes are added at the end. So the
+ gethostbyname2_r code will just ignore them. */
+ fct = __nss_lookup_function (nip, "gethostbyname2_r");
+
+ if (fct != NULL)
+ {
+ if (req->ai_family == AF_INET6 || req->ai_family == AF_UNSPEC)
+ {
+ gethosts (AF_INET6);
+ no_inet6_data = no_data;
+ inet6_status = status;
+ }
+ if (req->ai_family == AF_INET || req->ai_family == AF_UNSPEC
+ || (req->ai_family == AF_INET6
+ && (req->ai_flags & AI_V4MAPPED)
+ /* Avoid generating the mapped addresses if we
+ know we are not going to need them. */
+ && ((req->ai_flags & AI_ALL) || !res->got_ipv6)))
+ {
+ gethosts (AF_INET);
+
+ if (req->ai_family == AF_INET)
+ {
+ no_inet6_data = no_data;
+ inet6_status = status;
+ }
+ }
+
+ /* If we found one address for AF_INET or AF_INET6,
+ don't continue the search. */
+ if (inet6_status == NSS_STATUS_SUCCESS
+ || status == NSS_STATUS_SUCCESS)
+ {
+ if ((req->ai_flags & AI_CANONNAME) != 0 && canon == NULL)
+ {
+ char *canonbuf = getcanonname (nip, at, name);
+ if (canonbuf == NULL)
+ {
+ result = -EAI_MEMORY;
+ goto free_and_return;
+ }
+ canon = canonbuf;
+ }
+ status = NSS_STATUS_SUCCESS;
+ }
+ else
+ {
+ /* We can have different states for AF_INET and
+ AF_INET6. Try to find a useful one for both. */
+ if (inet6_status == NSS_STATUS_TRYAGAIN)
+ status = NSS_STATUS_TRYAGAIN;
+ else if (status == NSS_STATUS_UNAVAIL
+ && inet6_status != NSS_STATUS_UNAVAIL)
+ status = inet6_status;
+ }
+ }
+ else
+ {
+ /* Could not locate any of the lookup functions.
+ The NSS lookup code does not consistently set
+ errno, so we need to supply our own error
+ code here. The root cause could either be a
+ resource allocation failure, or a missing
+ service function in the DSO (so it should not
+ be listed in /etc/nsswitch.conf). Assume the
+ former, and return EBUSY. */
+ status = NSS_STATUS_UNAVAIL;
+ __set_h_errno (NETDB_INTERNAL);
+ __set_errno (EBUSY);
+ }
+ }
+
+ if (nss_next_action (nip, status) == NSS_ACTION_RETURN)
+ break;
+
+ /* Discard all previous results on CONTINUE. Allocations will get
+ freed at the end of gaih_cleanup, so only adjust PAT and free
+ CANONBUF if it was allocated. */
+ if (nss_next_action (nip, status) == NSS_ACTION_CONTINUE)
+ {
+ at = NULL;
+ pat = &at;
+ free (canon);
+ canon = NULL;
+ }
+
+ nip++;
+ if (nip->module == NULL)
+ no_more = -1;
+ }
+
+ /* If we have a failure which sets errno, report it using
+ EAI_SYSTEM. */
+ if ((status == NSS_STATUS_TRYAGAIN || status == NSS_STATUS_UNAVAIL)
+ && h_errno == NETDB_INTERNAL)
+ {
+ result = -EAI_SYSTEM;
+ goto free_and_return;
+ }
+
+ if (no_data != 0 && no_inet6_data != 0)
+ {
+ /* If both requests timed out report this. */
+ if (no_data == EAI_AGAIN && no_inet6_data == EAI_AGAIN)
+ result = -EAI_AGAIN;
+ else
+ /* We made requests but they turned out no data. The name
+ is known, though. */
+ result = -EAI_NODATA;
+ }
+
+free_and_return:
+ __resolv_context_put (res_ctx);
+
+ if (result != 0)
+ at = NULL;
+
+ if (at == NULL)
+ free (canon);
+ else
+ at->name = canon;
+
+ res->at = at;
+ return result;
+}
+
static int
process_canonname (const struct addrinfo *req, const char *orig_name,
char **canonp)
@@ -876,259 +1137,17 @@ gaih_inet (const char *name, const struct gaih_service *service,
}
#endif
- /* For NSS lookups, use PAT to track the end of the tuple list so that
- multiple lookups append to the end of the latest list. */
- struct gaih_addrtuple **pat = &at;
- int no_data = 0;
- int no_inet6_data = 0;
- nss_action_list nip;
- enum nss_status inet6_status = NSS_STATUS_UNAVAIL;
- enum nss_status status = NSS_STATUS_UNAVAIL;
- int no_more;
- struct resolv_context *res_ctx = NULL;
-
- no_more = !__nss_database_get (nss_database_hosts, &nip);
-
- /* If we are looking for both IPv4 and IPv6 address we don't
- want the lookup functions to automatically promote IPv4
- addresses to IPv6 addresses, so we use the no_inet6
- function variant. */
- res_ctx = __resolv_context_get ();
- if (res_ctx == NULL)
- no_more = 1;
-
- while (!no_more)
- {
- no_data = 0;
- nss_gethostbyname4_r *fct4 = NULL;
-
- /* gethostbyname4_r sends out parallel A and AAAA queries and
- is thus only suitable for PF_UNSPEC. */
- if (req->ai_family == PF_UNSPEC)
- fct4 = __nss_lookup_function (nip, "gethostbyname4_r");
-
- if (fct4 != NULL)
- {
- size_t length = 1024;
- char *buf = malloc (length);
-
- while (1)
- {
- *pat = NULL;
- status = DL_CALL_FCT (fct4, (name, pat,
- buf, length,
- &errno, &h_errno,
- NULL));
- if (status == NSS_STATUS_SUCCESS)
- break;
- if (status != NSS_STATUS_TRYAGAIN
- || errno != ERANGE || h_errno != NETDB_INTERNAL)
- {
- if (h_errno == TRY_AGAIN)
- no_data = EAI_AGAIN;
- else
- no_data = h_errno == NO_DATA;
- break;
- }
-
- length *= 2;
- free (buf);
- if ((buf = malloc (length)) == NULL)
- {
- __resolv_context_put (res_ctx);
- result = -EAI_MEMORY;
- goto free_and_return;
- }
- }
-
- if (!gaih_lookup_result_push_alloc (&res, buf))
- {
- result = -EAI_MEMORY;
- goto free_and_return;
- }
-
- if (status == NSS_STATUS_SUCCESS)
- {
- assert (!no_data);
- no_data = 1;
-
- if ((req->ai_flags & AI_CANONNAME) != 0 && canon == NULL)
- {
- char *canonbuf = __strdup ((*pat)->name);
- if (canonbuf == NULL)
- {
- __resolv_context_put (res_ctx);
- result = -EAI_MEMORY;
- goto free_and_return;
- }
- canon = canonbuf;
- }
-
- while (*pat != NULL)
- {
- if ((*pat)->family == AF_INET
- && req->ai_family == AF_INET6
- && (req->ai_flags & AI_V4MAPPED) != 0)
- {
- uint32_t *pataddr = (*pat)->addr;
- (*pat)->family = AF_INET6;
- pataddr[3] = pataddr[0];
- pataddr[2] = htonl (0xffff);
- pataddr[1] = 0;
- pataddr[0] = 0;
- pat = &((*pat)->next);
- no_data = 0;
- }
- else if (req->ai_family == AF_UNSPEC
- || (*pat)->family == req->ai_family)
- {
- pat = &((*pat)->next);
-
- no_data = 0;
- if (req->ai_family == AF_INET6)
- got_ipv6 = true;
- }
- else
- *pat = ((*pat)->next);
- }
- }
-
- no_inet6_data = no_data;
- }
- else
- {
- nss_gethostbyname3_r *fct = NULL;
- if (req->ai_flags & AI_CANONNAME)
- /* No need to use this function if we do not look for
- the canonical name. The function does not exist in
- all NSS modules and therefore the lookup would
- often fail. */
- fct = __nss_lookup_function (nip, "gethostbyname3_r");
- if (fct == NULL)
- /* We are cheating here. The gethostbyname2_r
- function does not have the same interface as
- gethostbyname3_r but the extra arguments the
- latter takes are added at the end. So the
- gethostbyname2_r code will just ignore them. */
- fct = __nss_lookup_function (nip, "gethostbyname2_r");
-
- if (fct != NULL)
- {
- if (req->ai_family == AF_INET6
- || req->ai_family == AF_UNSPEC)
- {
- gethosts (AF_INET6);
- no_inet6_data = no_data;
- inet6_status = status;
- }
- if (req->ai_family == AF_INET
- || req->ai_family == AF_UNSPEC
- || (req->ai_family == AF_INET6
- && (req->ai_flags & AI_V4MAPPED)
- /* Avoid generating the mapped addresses if we
- know we are not going to need them. */
- && ((req->ai_flags & AI_ALL) || !got_ipv6)))
- {
- gethosts (AF_INET);
-
- if (req->ai_family == AF_INET)
- {
- no_inet6_data = no_data;
- inet6_status = status;
- }
- }
-
- /* If we found one address for AF_INET or AF_INET6,
- don't continue the search. */
- if (inet6_status == NSS_STATUS_SUCCESS
- || status == NSS_STATUS_SUCCESS)
- {
- if ((req->ai_flags & AI_CANONNAME) != 0
- && canon == NULL)
- {
- char *canonbuf = getcanonname (nip, at, name);
- if (canonbuf == NULL)
- {
- __resolv_context_put (res_ctx);
- result = -EAI_MEMORY;
- goto free_and_return;
- }
- canon = canonbuf;
- }
- status = NSS_STATUS_SUCCESS;
- }
- else
- {
- /* We can have different states for AF_INET and
- AF_INET6. Try to find a useful one for both. */
- if (inet6_status == NSS_STATUS_TRYAGAIN)
- status = NSS_STATUS_TRYAGAIN;
- else if (status == NSS_STATUS_UNAVAIL
- && inet6_status != NSS_STATUS_UNAVAIL)
- status = inet6_status;
- }
- }
- else
- {
- /* Could not locate any of the lookup functions.
- The NSS lookup code does not consistently set
- errno, so we need to supply our own error
- code here. The root cause could either be a
- resource allocation failure, or a missing
- service function in the DSO (so it should not
- be listed in /etc/nsswitch.conf). Assume the
- former, and return EBUSY. */
- status = NSS_STATUS_UNAVAIL;
- __set_h_errno (NETDB_INTERNAL);
- __set_errno (EBUSY);
- }
- }
-
- if (nss_next_action (nip, status) == NSS_ACTION_RETURN)
- break;
-
- /* Discard the previous result on CONTINUE. Allocations will get
- freed at the end with func_cleanup, so only adjust PAT and free
- CANONBUF if it was allocated. */
- if (nss_next_action (nip, status) == NSS_ACTION_CONTINUE)
- {
- at = NULL;
- pat = &at;
- free (canon);
- canon = NULL;
- }
-
- nip++;
- if (nip->module == NULL)
- no_more = -1;
- }
-
- __resolv_context_put (res_ctx);
-
- /* If we have a failure which sets errno, report it using
- EAI_SYSTEM. */
- if ((status == NSS_STATUS_TRYAGAIN || status == NSS_STATUS_UNAVAIL)
- && h_errno == NETDB_INTERNAL)
- {
- result = -EAI_SYSTEM;
- goto free_and_return;
- }
-
- if (no_data != 0 && no_inet6_data != 0)
+ if ((result = get_nss_addresses (name, req, tmpbuf, &res)) != 0)
+ goto free_and_return;
+ else if (res.at != NULL)
{
- /* If both requests timed out report this. */
- if (no_data == EAI_AGAIN && no_inet6_data == EAI_AGAIN)
- result = -EAI_AGAIN;
- else
- /* We made requests but they turned out no data. The name
- is known, though. */
- result = -EAI_NODATA;
-
- goto free_and_return;
+ at = res.at;
+ canon = at->name;
+ got_ipv6 = res.got_ipv6;
}
process_list:
- if (at == NULL || at->family == AF_UNSPEC)
+ if (at == NULL)
{
result = -EAI_NONAME;
goto free_and_return;
next reply other threads:[~2022-03-01 2:41 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-01 2:41 Siddhesh Poyarekar [this message]
2022-03-07 16:56 Siddhesh Poyarekar
2022-03-08 14:10 Siddhesh Poyarekar
2022-03-14 14:17 Siddhesh Poyarekar
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