Hey Noah, On Thu, 22 Sep 2011, Noah Watkins wrote: > Change ceph_parse_ips to take either names given as > IP addresses or standard hostnames (e.g. localhost). > The DNS lookup is done using the dns_resolver facility > similar to its use in AFS, NFS, and CIFS.
Currently the dns resolution is handled by mount.ceph and 'rbd map/unmap'. I don't think that will go away (at the very least need to support old kernels). Allowing this in the raw kernel interface would be nice, but I don't think we want make DNS_RESOLVER a strict dependency, since it's new, kind of kludgey, and a ripe target for compiling out of small or secure kernels. Can you make it build either with or without it? Thanks! sage > > Signed-off-by: Noah Watkins <[email protected]> > --- > net/ceph/Kconfig | 1 + > net/ceph/messenger.c | 106 > ++++++++++++++++++++++++++++++++++++++++++++------ > 2 files changed, 95 insertions(+), 12 deletions(-) > > diff --git a/net/ceph/Kconfig b/net/ceph/Kconfig > index be683f2..aac5fc8 100644 > --- a/net/ceph/Kconfig > +++ b/net/ceph/Kconfig > @@ -5,6 +5,7 @@ config CEPH_LIB > select CRYPTO_AES > select CRYPTO > select KEYS > + select DNS_RESOLVER > default n > help > Choose Y or M here to include cephlib, which provides the > diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c > index c340e2e..c22aa58 100644 > --- a/net/ceph/messenger.c > +++ b/net/ceph/messenger.c > @@ -11,6 +11,7 @@ > #include <linux/string.h> > #include <linux/bio.h> > #include <linux/blkdev.h> > +#include <linux/dns_resolver.h> > #include <net/tcp.h> > > #include <linux/ceph/libceph.h> > @@ -1078,6 +1079,93 @@ static void addr_set_port(struct > sockaddr_storage *ss, int p) > } > > /* > + * Unlike other *_pton function semantics, zero indicates success. > + */ > +static int ceph_pton(const char *str, size_t len, struct sockaddr_storage > *ss, > + char delim, const char **ipend) > +{ > + struct sockaddr_in *in4 = (void *)ss; > + struct sockaddr_in6 *in6 = (void *)ss; > + > + memset(ss, 0, sizeof(*ss)); > + > + if (in4_pton(str, len, (u8 *)&in4->sin_addr.s_addr, delim, ipend)) { > + ss->ss_family = AF_INET; > + return 0; > + } > + > + if (in6_pton(str, len, (u8 *)&in6->sin6_addr.s6_addr, delim, ipend)) { > + ss->ss_family = AF_INET6; > + return 0; > + } > + > + return -EINVAL; > +} > + > +/* > + * Extract hostname string and resolve using kernel DNS facility. > + */ > +static int ceph_dns_resolve_name(const char *name, size_t namelen, > + struct sockaddr_storage *ss, char delim, const char > **ipend) > +{ > + const char *end, *delim_p; > + char *colon_p, *ip_addr = NULL; > + int ip_len, ret; > + > + /* > + * The end of the hostname occurs immediately preceding the delimiter or > + * the port marker (':') where the delimiter takes precedence. > + */ > + delim_p = memchr(name, delim, namelen); > + colon_p = memchr(name, ':', namelen); > + > + if (delim_p && colon_p) > + end = delim_p < colon_p ? delim_p : colon_p; > + else if (!delim_p && colon_p) > + end = colon_p; > + else { > + end = delim_p; > + if (!end) /* case: hostname:/ */ > + end = name + namelen; > + } > + > + if (end <= name) > + return -EINVAL; > + > + /* do dns_resolve upcall */ > + ip_len = dns_query(NULL, name, end - name, NULL, &ip_addr, NULL); > + if (ip_len > 0) > + ret = ceph_pton(ip_addr, ip_len, ss, -1, NULL); > + else > + ret = -ESRCH; > + > + kfree(ip_addr); > + > + *ipend = end; > + > + pr_info("resolve '%.*s' (ret=%d): %s\n", (int)(end - name), name, > + ret, ret ? "failed" : ceph_pr_addr(ss)); > + > + return ret; > +} > + > +/* > + * Parse a server name (IP or hostname). If a valid IP address is not found > + * then try to extract a hostname to resolve using userspace DNS upcall. > + */ > +static int ceph_parse_server_name(const char *name, size_t namelen, > + struct sockaddr_storage *ss, char delim, const char > **ipend) > +{ > + int ret; > + > + ret = ceph_pton(name, namelen, ss, delim, ipend); > + if (ret) > + ret = ceph_dns_resolve_name(name, namelen, ss, delim, ipend); > + > + return ret; > +} > + > +/* > * Parse an ip[:port] list into an addr array. Use the default > * monitor port if a port isn't specified. > */ > @@ -1085,15 +1173,13 @@ int ceph_parse_ips(const char *c, const char *end, > struct ceph_entity_addr *addr, > int max_count, int *count) > { > - int i; > + int i, ret = -EINVAL; > const char *p = c; > > dout("parse_ips on '%.*s'\n", (int)(end-c), c); > for (i = 0; i < max_count; i++) { > const char *ipend; > struct sockaddr_storage *ss = &addr[i].in_addr; > - struct sockaddr_in *in4 = (void *)ss; > - struct sockaddr_in6 *in6 = (void *)ss; > int port; > char delim = ','; > > @@ -1102,15 +1188,11 @@ int ceph_parse_ips(const char *c, const char *end, > p++; > } > > - memset(ss, 0, sizeof(*ss)); > - if (in4_pton(p, end - p, (u8 *)&in4->sin_addr.s_addr, > - delim, &ipend)) > - ss->ss_family = AF_INET; > - else if (in6_pton(p, end - p, (u8 *)&in6->sin6_addr.s6_addr, > - delim, &ipend)) > - ss->ss_family = AF_INET6; > - else > + ret = ceph_parse_server_name(p, end - p, ss, delim, &ipend); > + if (ret) > goto bad; > + ret = -EINVAL; > + > p = ipend; > > if (delim == ']') { > @@ -1155,7 +1237,7 @@ int ceph_parse_ips(const char *c, const char *end, > > bad: > pr_err("parse_ips bad ip '%.*s'\n", (int)(end - c), c); > - return -EINVAL; > + return ret; > } > EXPORT_SYMBOL(ceph_parse_ips); > > -- > 1.7.6.1 > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
