Introduce a new DNS resolver function in utils/mount/network.c that uses
getaddrinfo(3), which supports AF_INET6, to resolve host names.
Replace the guts of nfs_gethostbyname() with a call to the new function.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
utils/mount/network.c | 78 +++++++++++++++++++++++++++++++++++++------------
utils/mount/network.h | 2 +
2 files changed, 61 insertions(+), 19 deletions(-)
diff --git a/utils/mount/network.c b/utils/mount/network.c
index ab7f6d0..30a4d40 100644
--- a/utils/mount/network.c
+++ b/utils/mount/network.c
@@ -144,32 +144,72 @@ static const unsigned long probe_mnt3_first[] = {
};
/**
+ * nfs_name_to_address - resolve hostname to an IPv4 or IPv6 socket address
+ * @hostname: pointer to C string containing DNS hostname to resolve
+ * @sap: pointer to buffer to fill with socket address
+ * @len: IN: size of buffer to fill; OUT: size of socket address
+ *
+ * Returns 1 and places a socket address at @sap if successful;
+ * otherwise zero.
+ */
+int nfs_name_to_address(const char *hostname,
+ const sa_family_t af_hint,
+ struct sockaddr *sap, socklen_t *salen)
+{
+ struct addrinfo *gai_results;
+ struct addrinfo gai_hint = {
+ .ai_family = af_hint,
+ .ai_flags = AI_ADDRCONFIG,
+ };
+ socklen_t len = *salen;
+ int error, ret = 0;
+
+ if (af_hint == AF_INET6)
+ gai_hint.ai_flags |= AI_V4MAPPED|AI_ALL;
+
+ *salen = 0;
+
+ error = getaddrinfo(hostname, NULL, &gai_hint, &gai_results);
+ if (error) {
+ nfs_error(_("%s: DNS resolution failed for %s: %s"),
+ progname, hostname, (error == EAI_SYSTEM ?
+ strerror(errno) : gai_strerror(error)));
+ return ret;
+ }
+
+ switch (gai_results->ai_addr->sa_family) {
+ case AF_INET:
+ case AF_INET6:
+ if (len >= gai_results->ai_addrlen) {
+ *salen = gai_results->ai_addrlen;
+ memcpy(sap, gai_results->ai_addr, *salen);
+ ret = 1;
+ }
+ break;
+ default:
+ /* things are really broken if we get here, so warn */
+ nfs_error(_("%s: unrecognized DNS resolution results for %s"),
+ progname, hostname);
+ break;
+ }
+
+ freeaddrinfo(gai_results);
+ return ret;
+}
+
+/**
* nfs_gethostbyname - resolve a hostname to an IPv4 address
* @hostname: pointer to a C string containing a DNS hostname
* @saddr: returns an IPv4 address
*
* Returns 1 if successful, otherwise zero.
*/
-int nfs_gethostbyname(const char *hostname, struct sockaddr_in *saddr)
+int nfs_gethostbyname(const char *hostname, struct sockaddr_in *sin)
{
- struct hostent *hp;
-
- saddr->sin_family = AF_INET;
- if (!inet_aton(hostname, &saddr->sin_addr)) {
- if ((hp = gethostbyname(hostname)) == NULL) {
- nfs_error(_("%s: can't get address for %s\n"),
- progname, hostname);
- return 0;
- } else {
- if (hp->h_length > sizeof(*saddr)) {
- nfs_error(_("%s: got bad hp->h_length\n"),
- progname);
- hp->h_length = sizeof(*saddr);
- }
- memcpy(&saddr->sin_addr, hp->h_addr, hp->h_length);
- }
- }
- return 1;
+ socklen_t len = sizeof(*sin);
+
+ return nfs_name_to_address(hostname, AF_INET,
+ (struct sockaddr *)sin, &len);
}
/*
diff --git a/utils/mount/network.h b/utils/mount/network.h
index e0a5dd5..9de13b5 100644
--- a/utils/mount/network.h
+++ b/utils/mount/network.h
@@ -51,6 +51,8 @@ static const struct timeval RETRY_TIMEOUT = { 3, 0 };
int probe_bothports(clnt_addr_t *, clnt_addr_t *);
int nfs_gethostbyname(const char *, struct sockaddr_in *);
+int nfs_name_to_address(const char *, const sa_family_t,
+ struct sockaddr *, socklen_t *);
int get_client_address(struct sockaddr_in *, struct sockaddr_in *);
int nfs_call_umount(clnt_addr_t *, dirpath *);
int clnt_ping(struct sockaddr_in *, const unsigned long,
--
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