Build TLS as a loadable module

* Support BUILD_TLS=module to be loaded as a module via config file or
  command line. e.g. redis-server --loadmodule redis-tls.so
* Updates to redismodule.h to allow it to be used side by side with
  server.h by defining REDISMODULE_CORE_MODULE
* Changes to server.h, redismodule.h and module.c to avoid repeated
  type declarations (gcc 4.8 doesn't like these)
* Add a mechanism for non-ABI neutral modules (ones who include
  server.h) to refuse loading if they detect not being built together with
  redis (release.c)
* Fix wrong signature of RedisModuleDefragFunc, this could break
  compilation of a module, but not the ABI
* Move initialization of listeners in server.c to be after loading
  the modules
* Config TLS after initialization of listeners
* Init cluster after initialization of listeners
* Add TLS module to CI
* Fix a test suite race conditions:
  Now that the listeners are initialized later, it's not sufficient to
  wait for the PID message in the log, we need to wait for the "Server
  Initialized" message.
* Fix issues with moduleconfigs test as a result from start_server
  waiting for "Server Initialized"
* Fix issues with modules/infra test as a result of an additional module
  present

Notes about Sentinel:
Sentinel can't really rely on the tls module, since it uses hiredis to
initiate connections and depends on OpenSSL (won't be able to use any
other connection modules for that), so it was decided that when TLS is
built as a module, sentinel does not support TLS at all.
This means that it keeps using redis_tls_ctx and redis_tls_client_ctx directly.

Example code of config in redis-tls.so(may be use in the future):
RedisModuleString *tls_cfg = NULL;

void tlsInfo(RedisModuleInfoCtx *ctx, int for_crash_report) {
    UNUSED(for_crash_report);
    RedisModule_InfoAddSection(ctx, "");
    RedisModule_InfoAddFieldLongLong(ctx, "var", 42);
}

int tlsCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
{
    if (argc != 2) return RedisModule_WrongArity(ctx);
    return RedisModule_ReplyWithString(ctx, argv[1]);
}

RedisModuleString *getStringConfigCommand(const char *name, void *privdata) {
    REDISMODULE_NOT_USED(name);
    REDISMODULE_NOT_USED(privdata);
    return tls_cfg;
}

int setStringConfigCommand(const char *name, RedisModuleString *new, void *privdata, RedisModuleString **err) {
    REDISMODULE_NOT_USED(name);
    REDISMODULE_NOT_USED(err);
    REDISMODULE_NOT_USED(privdata);
    if (tls_cfg) RedisModule_FreeString(NULL, tls_cfg);
    RedisModule_RetainString(NULL, new);
    tls_cfg = new;
    return REDISMODULE_OK;
}

int RedisModule_OnLoad(void *ctx, RedisModuleString **argv, int argc)
{
    ....
    if (RedisModule_CreateCommand(ctx,"tls",tlsCommand,"",0,0,0) == REDISMODULE_ERR)
        return REDISMODULE_ERR;

    if (RedisModule_RegisterStringConfig(ctx, "cfg", "", REDISMODULE_CONFIG_DEFAULT, getStringConfigCommand, setStringConfigCommand, NULL, NULL) == REDISMODULE_ERR)
        return REDISMODULE_ERR;

    if (RedisModule_LoadConfigs(ctx) == REDISMODULE_ERR) {
        if (tls_cfg) {
            RedisModule_FreeString(ctx, tls_cfg);
            tls_cfg = NULL;
        }
        return REDISMODULE_ERR;
    }
    ...
}

Co-authored-by: zhenwei pi <pizhenwei@bytedance.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/src/module.c b/src/module.c
index 7644e2c77..f0f49837b 100644
--- a/src/module.c
+++ b/src/module.c
@@ -69,14 +69,14 @@
  * pointers that have an API the module can call with them)
  * -------------------------------------------------------------------------- */
 
-typedef struct RedisModuleInfoCtx {
+struct RedisModuleInfoCtx {
     struct RedisModule *module;
     dict *requested_sections;
     sds info;           /* info string we collected so far */
     int sections;       /* number of sections we collected so far */
     int in_section;     /* indication if we're in an active section or not */
     int in_dict_field;  /* indication that we're currently appending to a dict */
-} RedisModuleInfoCtx;
+};
 
 /* This represents a shared API. Shared APIs will be used to populate
  * the server.sharedapi dictionary, mapping names of APIs exported by
@@ -12211,13 +12211,13 @@ const char *RM_GetCurrentCommandName(RedisModuleCtx *ctx) {
 /* The defrag context, used to manage state during calls to the data type
  * defrag callback.
  */
-typedef struct RedisModuleDefragCtx {
+struct RedisModuleDefragCtx {
     long defragged;
     long long int endtime;
     unsigned long *cursor;
     struct redisObject *key; /* Optional name of key processed, NULL when unknown. */
     int dbid;                /* The dbid of the key being processed, -1 when unknown. */
-} RedisModuleDefragCtx;
+};
 
 /* Register a defrag callback for global data, i.e. anything that the module
  * may allocate that is not tied to a specific data type.