added more flexible handling of client protocol

- allow different protocol versions for PAM and NSS
 - support more than one protocol version in the responder

4 files changed, 63 insertions, 2 deletions

diff --git a/server/responder/common/responder.h b/server/responder/common/responder.h
index f5d5246f..946418c8 100644
--- a/server/responder/common/responder.h
+++ b/server/responder/common/responder.h
@@ -43,6 +43,12 @@ struct cli_request {
     struct sss_packet *out;
 };
 
+struct cli_protocol_version {
+    uint32_t version;
+    char *date;
+    char *description;
+};
+
 struct sss_names_ctx {
     char *re_pattern;
     char *fq_fmt;
@@ -83,6 +89,7 @@ struct cli_ctx {
     struct tevent_fd *cfde;
     struct sockaddr_un addr;
     struct cli_request *creq;
+    struct cli_protocol_version *cli_protocol_version;
     int priv;
 };
 
@@ -111,6 +118,7 @@ int sss_parse_name(TALLOC_CTX *memctx,
 int sss_cmd_execute(struct cli_ctx *cctx, struct sss_cmd_table *sss_cmds);
 void sss_cmd_done(struct cli_ctx *cctx, void *freectx);
 int sss_cmd_get_version(struct cli_ctx *cctx);
+struct cli_protocol_version *register_cli_protocol_version(void);
 
 /* responder_dp.c */
 int sss_dp_init(struct resp_ctx *rctx, struct sbus_method dp_methods[]);
diff --git a/server/responder/common/responder_cmd.c b/server/responder/common/responder_cmd.c
index 33caa032..cab8b694 100644
--- a/server/responder/common/responder_cmd.c
+++ b/server/responder/common/responder_cmd.c
@@ -36,9 +36,39 @@ void sss_cmd_done(struct cli_ctx *cctx, void *freectx)
 
 int sss_cmd_get_version(struct cli_ctx *cctx)
 {
+    uint8_t *req_body;
+    size_t req_blen;
     uint8_t *body;
     size_t blen;
     int ret;
+    uint32_t client_version;
+    int i;
+    static struct cli_protocol_version *cli_protocol_version = NULL;
+
+    cctx->cli_protocol_version = NULL;
+
+    if (cli_protocol_version == NULL) {
+        cli_protocol_version = register_cli_protocol_version();
+    }
+
+    if (cli_protocol_version != NULL) {
+        cctx->cli_protocol_version = &cli_protocol_version[0];
+
+        sss_packet_get_body(cctx->creq->in, &req_body, &req_blen);
+        if (req_blen == sizeof(uint32_t)) {
+            client_version = (uint32_t ) *req_body;
+            DEBUG(4, ("Received client version [%d].\n", client_version));
+
+            i=0;
+            while(cli_protocol_version[i].version>0) {
+                if (cli_protocol_version[i].version == client_version) {
+                    cctx->cli_protocol_version = &cli_protocol_version[i];
+                    break;
+                }
+                i++;
+            }
+        }
+    }
 
     /* create response packet */
     ret = sss_packet_new(cctx->creq, sizeof(uint32_t),
@@ -48,7 +78,9 @@ int sss_cmd_get_version(struct cli_ctx *cctx)
         return ret;
     }
     sss_packet_get_body(cctx->creq->out, &body, &blen);
-    ((uint32_t *)body)[0] = SSS_PROTOCOL_VERSION;
+    ((uint32_t *)body)[0] = cctx->cli_protocol_version!=NULL ?
+                                cctx->cli_protocol_version->version : 0;
+    DEBUG(4, ("Offered version [%d].\n", ((uint32_t *)body)[0]));
 
     sss_cmd_done(cctx, NULL);
     return EOK;
diff --git a/server/responder/nss/nsssrv_cmd.c b/server/responder/nss/nsssrv_cmd.c
index cf491ccf..a8a3c686 100644
--- a/server/responder/nss/nsssrv_cmd.c
+++ b/server/responder/nss/nsssrv_cmd.c
@@ -3105,6 +3105,16 @@ done:
     return EOK;
 }
 
+struct cli_protocol_version *register_cli_protocol_version(void)
+{
+    static struct cli_protocol_version nss_cli_protocol_version[] = {
+        {1, "2008-09-05", "initial version, \\0 terminated strings"},
+        {0, NULL, NULL}
+    };
+
+    return nss_cli_protocol_version;
+}
+
 static struct sss_cmd_table nss_cmds[] = {
     {SSS_GET_VERSION, sss_cmd_get_version},
     {SSS_NSS_GETPWNAM, nss_cmd_getpwnam},
diff --git a/server/responder/pam/pamsrv_cmd.c b/server/responder/pam/pamsrv_cmd.c
index df0cba45..02b52138 100644
--- a/server/responder/pam/pamsrv_cmd.c
+++ b/server/responder/pam/pamsrv_cmd.c
@@ -656,7 +656,18 @@ static int pam_cmd_chauthtok(struct cli_ctx *cctx) {
     return pam_forwarder(cctx, SSS_PAM_CHAUTHTOK);
 }
 
-struct sss_cmd_table *register_sss_cmds(void) {
+struct cli_protocol_version *register_cli_protocol_version(void)
+{
+    static struct cli_protocol_version pam_cli_protocol_version[] = {
+        {1, "2008-09-05", "initial version, \\0 terminated strings"},
+        {0, NULL, NULL}
+    };
+
+    return pam_cli_protocol_version;
+}
+
+struct sss_cmd_table *register_sss_cmds(void)
+{
     static struct sss_cmd_table sss_cmds[] = {
         {SSS_GET_VERSION, sss_cmd_get_version},
         {SSS_PAM_AUTHENTICATE, pam_cmd_authenticate},