From 068dbee9ca7bf5b37330eff91c94ae10f288d09f Mon Sep 17 00:00:00 2001 From: Jakub Hrozek Date: Tue, 17 May 2011 16:49:19 +0200 Subject: Add new options to override shell value https://fedorahosted.org/sssd/ticket/742 --- src/responder/nss/nsssrv.c | 82 ++++++++++++++++++++++++++++++++++++++++++ src/responder/nss/nsssrv.h | 3 ++ src/responder/nss/nsssrv_cmd.c | 39 +++++++++++++++++++- 3 files changed, 123 insertions(+), 1 deletion(-) (limited to 'src/responder') diff --git a/src/responder/nss/nsssrv.c b/src/responder/nss/nsssrv.c index a5323bd7..b9d548e4 100644 --- a/src/responder/nss/nsssrv.c +++ b/src/responder/nss/nsssrv.c @@ -48,6 +48,9 @@ #define DEFAULT_PWFIELD "*" +#define SHELL_REALLOC_INCREMENT 5 +#define SHELL_REALLOC_MAX 50 + struct sbus_method monitor_nss_methods[] = { { MON_CLI_METHOD_PING, monitor_common_pong }, { MON_CLI_METHOD_RES_INIT, monitor_common_res_init }, @@ -63,6 +66,71 @@ struct sbus_interface monitor_nss_interface = { NULL }; +static errno_t nss_get_etc_shells(TALLOC_CTX *mem_ctx, char ***_shells) +{ + int i = 0; + char *sh; + char **shells = NULL; + TALLOC_CTX *tmp_ctx; + errno_t ret; + int size; + + tmp_ctx = talloc_new(NULL); + if (!tmp_ctx) return ENOMEM; + + shells = talloc_array(tmp_ctx, char *, SHELL_REALLOC_INCREMENT); + if (!shells) { + ret = ENOMEM; + goto done; + } + size = SHELL_REALLOC_INCREMENT; + + setusershell(); + while ((sh = getusershell())) { + shells[i] = talloc_strdup(shells, sh); + if (!shells[i]) { + endusershell(); + ret = ENOMEM; + goto done; + } + DEBUG(6, ("Found shell %s in /etc/shells\n", shells[i])); + i++; + + if (i == size) { + size += SHELL_REALLOC_INCREMENT; + if (size > SHELL_REALLOC_MAX) { + DEBUG(0, ("Reached maximum number of shells [%d]. " + "Users may be denied access. " + "Please check /etc/shells for sanity\n", + SHELL_REALLOC_MAX)); + break; + } + shells = talloc_realloc(NULL, shells, char *, + size); + if (!shells) { + ret = ENOMEM; + goto done; + } + } + } + endusershell(); + + if (i + 1 < size) { + shells = talloc_realloc(NULL, shells, char *, i + 1); + if (!shells) { + ret = ENOMEM; + goto done; + } + } + shells[i] = NULL; + + *_shells = talloc_move(mem_ctx, &shells); + ret = EOK; +done: + talloc_zfree(tmp_ctx); + return ret; +} + static int nss_get_config(struct nss_ctx *nctx, struct resp_ctx *rctx, struct confdb_ctx *cdb) @@ -115,6 +183,20 @@ static int nss_get_config(struct nss_ctx *nctx, &nctx->override_homedir); if (ret != EOK) goto done; + ret = confdb_get_string_as_list(cdb, nctx, CONFDB_NSS_CONF_ENTRY, + CONFDB_NSS_ALLOWED_SHELL, + &nctx->allowed_shells); + if (ret != EOK && ret != ENOENT) goto done; + + ret = nss_get_etc_shells(nctx, &nctx->etc_shells); + if (ret != EOK) goto done; + + ret = confdb_get_string(cdb, nctx, CONFDB_NSS_CONF_ENTRY, + CONFDB_NSS_SHELL_FALLBACK, + CONFDB_DEFAULT_SHELL_FALLBACK, + &nctx->shell_fallback); + if (ret != EOK) goto done; + ret = 0; done: talloc_free(tmpctx); diff --git a/src/responder/nss/nsssrv.h b/src/responder/nss/nsssrv.h index e3e774f9..f9aff566 100644 --- a/src/responder/nss/nsssrv.h +++ b/src/responder/nss/nsssrv.h @@ -59,6 +59,9 @@ struct nss_ctx { char *pwfield; char *override_homedir; + char **allowed_shells; + char **etc_shells; + char *shell_fallback; }; struct nss_packet; diff --git a/src/responder/nss/nsssrv_cmd.c b/src/responder/nss/nsssrv_cmd.c index 4386da71..e698b5ec 100644 --- a/src/responder/nss/nsssrv_cmd.c +++ b/src/responder/nss/nsssrv_cmd.c @@ -305,6 +305,43 @@ static const char *get_homedir_override(TALLOC_CTX *mem_ctx, ldb_msg_find_attr_as_string(msg, SYSDB_HOMEDIR, NULL)); } +static const char *get_shell_override(TALLOC_CTX *mem_ctx, + struct ldb_message *msg, + struct nss_ctx *nctx) +{ + const char *user_shell; + int i; + + user_shell = ldb_msg_find_attr_as_string(msg, SYSDB_SHELL, NULL); + if (!user_shell) return NULL; + if (!nctx->allowed_shells) return talloc_strdup(mem_ctx, user_shell); + + for (i=0; nctx->etc_shells[i]; i++) { + if (strcmp(user_shell, nctx->etc_shells[i]) == 0) { + DEBUG(9, ("Shell %s found in /etc/shells\n", + nctx->etc_shells[i])); + break; + } + } + + if (nctx->etc_shells[i]) { + DEBUG(9, ("Using original shell '%s'\n", user_shell)); + return talloc_strdup(mem_ctx, user_shell); + } + + for (i=0; nctx->allowed_shells[i]; i++) { + if (strcmp(nctx->allowed_shells[i], user_shell) == 0) { + DEBUG(5, ("The shell '%s' is allowed but does not exist. " + "Using fallback\n", user_shell)); + return talloc_strdup(mem_ctx, nctx->shell_fallback); + } + } + + DEBUG(5, ("The shell '%s' is not allowed and does not exist.\n", + user_shell)); + return talloc_strdup(mem_ctx, NOLOGIN_SHELL); +} + static int fill_pwent(struct sss_packet *packet, struct sss_domain_info *dom, struct nss_ctx *nctx, @@ -373,7 +410,7 @@ static int fill_pwent(struct sss_packet *packet, gecos = ldb_msg_find_attr_as_string(msg, SYSDB_GECOS, NULL); homedir = get_homedir_override(tmp_ctx, msg, nctx, dom, name, uid); - shell = ldb_msg_find_attr_as_string(msg, SYSDB_SHELL, NULL); + shell = get_shell_override(tmp_ctx, msg, nctx); if (!gecos) gecos = ""; if (!homedir) homedir = "/"; -- cgit