commit 6e3fed9d20d6b7ef4b69dd7cfcdd7bbaf1c9a9cb Author: Siddhesh Poyarekar Date: Mon Mar 7 20:24:37 2022 +0530 gaih_inet: split loopback lookup into its own function Flatten the condition nesting and replace the alloca for RET.AT/ATR with a single array LOCAL_AT[2]. This gets rid of alloca and alloca accounting. `git diff -b` is probably the best way to view this change since much of the diff is whitespace changes. Signed-off-by: Siddhesh Poyarekar Reviewed-by: DJ Delorie (cherry picked from commit 657472b2a50f67b12e5bbe5827582c9c2bb82dc3) diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c index 6be109d07f7fcce0..827c43b369836de9 100644 --- a/sysdeps/posix/getaddrinfo.c +++ b/sysdeps/posix/getaddrinfo.c @@ -1004,6 +1004,32 @@ try_simple_gethostbyname (const char *name, const struct addrinfo *req, return -EAI_NODATA; } +/* Add local address information into RES. RES->AT is assumed to have enough + space for two tuples and is zeroed out. */ + +static void +get_local_addresses (const struct addrinfo *req, struct gaih_result *res) +{ + struct gaih_addrtuple *atr = res->at; + if (req->ai_family == AF_UNSPEC) + res->at->next = res->at + 1; + + if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6) + { + res->at->family = AF_INET6; + if ((req->ai_flags & AI_PASSIVE) == 0) + memcpy (res->at->addr, &in6addr_loopback, sizeof (struct in6_addr)); + atr = res->at->next; + } + + if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET) + { + atr->family = AF_INET; + if ((req->ai_flags & AI_PASSIVE) == 0) + atr->addr[0] = htonl (INADDR_LOOPBACK); + } +} + static int gaih_inet (const char *name, const struct gaih_service *service, const struct addrinfo *req, struct addrinfo **pai, @@ -1014,10 +1040,6 @@ gaih_inet (const char *name, const struct gaih_service *service, const char *orig_name = name; - /* Reserve stack memory for the scratch buffer in the getaddrinfo - function. */ - size_t alloca_used = sizeof (struct scratch_buffer); - int rc; if ((rc = get_servtuples (service, req, st, tmpbuf)) != 0) return rc; @@ -1027,76 +1049,51 @@ gaih_inet (const char *name, const struct gaih_service *service, int result = 0; struct gaih_result res = {0}; - if (name != NULL) + struct gaih_addrtuple local_at[2] = {0}; + + res.at = local_at; + + if (__glibc_unlikely (name == NULL)) { - if (req->ai_flags & AI_IDN) - { - char *out; - result = __idna_to_dns_encoding (name, &out); - if (result != 0) - return -result; - name = out; - malloc_name = true; - } + get_local_addresses (req, &res); + goto process_list; + } - res.at = alloca_account (sizeof (struct gaih_addrtuple), alloca_used); - res.at->scopeid = 0; - res.at->next = NULL; + if (req->ai_flags & AI_IDN) + { + char *out; + result = __idna_to_dns_encoding (name, &out); + if (result != 0) + return -result; + name = out; + malloc_name = true; + } - if ((result = text_to_binary_address (name, req, &res)) != 0) - goto free_and_return; - else if (res.at != NULL) - goto process_list; + if ((result = text_to_binary_address (name, req, &res)) != 0) + goto free_and_return; + else if (res.at != NULL) + goto process_list; - if ((result = try_simple_gethostbyname (name, req, tmpbuf, &res)) != 0) - goto free_and_return; - else if (res.at != NULL) - goto process_list; + if ((result = try_simple_gethostbyname (name, req, tmpbuf, &res)) != 0) + goto free_and_return; + else if (res.at != NULL) + goto process_list; #ifdef USE_NSCD - if ((result = get_nscd_addresses (name, req, &res)) != 0) - goto free_and_return; - else if (res.at != NULL) - goto process_list; + if ((result = get_nscd_addresses (name, req, &res)) != 0) + goto free_and_return; + else if (res.at != NULL) + goto process_list; #endif - if ((result = get_nss_addresses (name, req, tmpbuf, &res)) != 0) - goto free_and_return; - else if (res.at != NULL) - goto process_list; - - /* None of the lookups worked, so name not found. */ - result = -EAI_NONAME; - goto free_and_return; - } - else - { - struct gaih_addrtuple *atr; - atr = res.at = alloca_account (sizeof (struct gaih_addrtuple), - alloca_used); - memset (res.at, '\0', sizeof (struct gaih_addrtuple)); - - if (req->ai_family == AF_UNSPEC) - { - res.at->next = __alloca (sizeof (struct gaih_addrtuple)); - memset (res.at->next, '\0', sizeof (struct gaih_addrtuple)); - } - - if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6) - { - res.at->family = AF_INET6; - if ((req->ai_flags & AI_PASSIVE) == 0) - memcpy (res.at->addr, &in6addr_loopback, sizeof (struct in6_addr)); - atr = res.at->next; - } + if ((result = get_nss_addresses (name, req, tmpbuf, &res)) != 0) + goto free_and_return; + else if (res.at != NULL) + goto process_list; - if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET) - { - atr->family = AF_INET; - if ((req->ai_flags & AI_PASSIVE) == 0) - atr->addr[0] = htonl (INADDR_LOOPBACK); - } - } + /* None of the lookups worked, so name not found. */ + result = -EAI_NONAME; + goto free_and_return; process_list: {