The server side can enforce its negotiation limits

diff --git a/checksum.c b/checksum.c
index 7c9151731bc346e8cb49ae9c6e554e85ff297273..125ee5b0b4ca4376a8b81693f72f67df0925fd94 100644 (file)
--- a/checksum.c
+++ b/checksum.c
@@ -99,6 +99,8 @@ void parse_checksum_choice(int final_call)
                        checksum_type = parse_csum_name(cp+1, -1);
                } else
                        xfersum_type = checksum_type = parse_csum_name(checksum_choice, -1);
+               if (am_server && checksum_choice)
+                       validate_choice_vs_env(xfersum_type, checksum_type);
        }
 
        if (xfersum_type == CSUM_NONE)

diff --git a/compat.c b/compat.c
index 7a97cfc36b2a958898cd5d334a2abd3e620fef81..4f225f29e9b0b9a4d91838d7c7581b177c41545d 100644 (file)
--- a/compat.c
+++ b/compat.c
@@ -173,6 +173,8 @@ void parse_compress_choice(int final_call)
                        exit_cleanup(RERR_UNSUPPORTED);
                }
                do_compression = nni->num;
+               if (am_server)
+                       validate_choice_vs_env(do_compression, -1);
        } else if (do_compression)
                do_compression = CPRES_ZLIB;
        else
@@ -317,8 +319,14 @@ static void recv_negotiate_str(int f_in, struct name_num_obj *nno, char *tmpbuf,
        if (len > 0) {
                int best = nno->saw_len; /* We want best == 1 from the client list, so start with a big number. */
                char *tok;
-               if (am_server)
-                       init_nno_saw(nno, 1); /* Since we're parsing client names, anything we parse first is #1. */
+               if (am_server) {
+                       int j;
+                       /* Since we're parsing client names, anything in our list that we parse first is #1. */
+                       for (j = 0; j < nno->saw_len; j++) {
+                               if (nno->saw[j])
+                                       nno->saw[j] = 1;
+                       }
+               }
                for (tok = strtok(tmpbuf, " \t"); tok; tok = strtok(NULL, " \t")) {
                        struct name_num_item *nni = get_nni_by_name(nno, tok, -1);
                        if (!nni || !nno->saw[nni->num] || best <= nno->saw[nni->num])
@@ -337,11 +345,37 @@ static void recv_negotiate_str(int f_in, struct name_num_obj *nno, char *tmpbuf,
                }
        }
 
-       if (!am_server)
-               rprintf(FERROR, "Failed to negotiate a common %s\n", nno->type);
+       if (!am_server || !do_negotiated_strings)
+               rprintf(FERROR, "Failed to negotiate a %s choice.\n", nno->type);
        exit_cleanup(RERR_UNSUPPORTED);
 }
 
+/* If num2 < 0 then the caller is checking compress values, otherwise checksum values. */
+void validate_choice_vs_env(int num1, int num2)
+{
+       struct name_num_obj *nno = num2 < 0 ? &valid_compressions : &valid_checksums;
+       const char *list_str = getenv(num2 < 0 ? "RSYNC_COMPRESS_LIST" : "RSYNC_CHECKSUM_LIST");
+       char tmpbuf[MAX_NSTR_STRLEN];
+
+       if (!list_str || !*list_str)
+               return;
+
+       init_nno_saw(nno, 0);
+       parse_nni_str(nno, list_str, tmpbuf, MAX_NSTR_STRLEN);
+
+       if (num2 >= 0) // If "md4" is in the env list, all the old MD4 choices are OK too.
+               nno->saw[CSUM_MD4_ARCHAIC] = nno->saw[CSUM_MD4_BUSTED] = nno->saw[CSUM_MD4_OLD] = nno->saw[CSUM_MD4];
+
+       if (!nno->saw[num1] || (num2 >= 0 && !nno->saw[num2])) {
+               rprintf(FERROR, "Your --%s-choice value (%s) was refused by the server.\n", 
+                       num2 < 0 ? "compress" : "checksum", num2 < 0 ? compress_choice : checksum_choice);
+               exit_cleanup(RERR_UNSUPPORTED);
+       }
+
+       free(nno->saw);
+       nno->saw = NULL;
+}
+
 /* The saw buffer is initialized and used to store ordinal values from 1 to N
  * for the order of the args in the array.  If dup_markup == '\0', duplicates
  * are removed otherwise the char is prefixed to the duplicate term and, if it