Move SMTP from contrib to main lwIP rep - with TLS support, it becomes useful again

src/Filelists.mk

@@ -160,6 +160,9 @@ HTTPDFILES=$(LWIPDIR)/apps/httpd/fs.c \
 # LWIPERFFILES: IPERF server
 LWIPERFFILES=$(LWIPDIR)/apps/lwiperf/lwiperf.c
 
+# SMTPFILES: SMTP client
+SMTPFILES=$(LWIPDIR)/apps/smtp/smtp.c
+
 # SNTPFILES: SNTP client
 SNTPFILES=$(LWIPDIR)/apps/sntp/sntp.c
 
@@ -183,6 +186,7 @@ ALTCP_TLS_MBEDTLS=$(LWIPDIR)/apps/altcp_tls/altcp_tls_mbedtls.c \
 LWIPAPPFILES=$(SNMPFILES) \
 	$(HTTPDFILES) \
 	$(LWIPERFFILES) \
+	$(SMTPFILES) \
 	$(SNTPFILES) \
 	$(MDNSFILES) \
 	$(NETBIOSNSFILES) \

src/include/lwip/apps/smtp.h

@@ -0,0 +1,123 @@
+#ifndef LWIP_HDR_APPS_SMTP_H
+#define LWIP_HDR_APPS_SMTP_H
+
+/** Set this to 1 to enable data handler callback on BODY */
+#ifndef SMTP_BODYDH
+#define SMTP_BODYDH               0
+#endif
+
+#include "lwip/err.h"
+
+/** The default TCP port used for SMTP */
+#define SMTP_DEFAULT_PORT         25
+/** The default TCP port used for SMTPS */
+#define SMTPS_DEFAULT_PORT        465
+
+/** Email successfully sent */
+#define SMTP_RESULT_OK            0
+/** Unknown error */
+#define SMTP_RESULT_ERR_UNKNOWN   1
+/** Connection to server failed */
+#define SMTP_RESULT_ERR_CONNECT   2
+/** Failed to resolve server hostname */
+#define SMTP_RESULT_ERR_HOSTNAME  3
+/** Connection unexpectedly closed by remote server */
+#define SMTP_RESULT_ERR_CLOSED    4
+/** Connection timed out (server didn't respond in time) */
+#define SMTP_RESULT_ERR_TIMEOUT   5
+/** Server responded with an unknown response code */
+#define SMTP_RESULT_ERR_SVR_RESP  6
+/** Out of resources locally */
+#define SMTP_RESULT_ERR_MEM       7
+
+/** Prototype of an smtp callback function
+ *
+ * @param arg argument specified when initiating the email
+ * @param smtp_result result of the mail transfer (see defines SMTP_RESULT_*)
+ * @param srv_err if aborted by the server, this contains the error code received
+ * @param err an error returned by internal lwip functions, can help to specify
+ *            the source of the error but must not necessarily be != ERR_OK
+ */
+typedef void (*smtp_result_fn)(void *arg, u8_t smtp_result, u16_t srv_err, err_t err);
+
+/** This structure is used as argument for smtp_send_mail_int(),
+ * which in turn can be used with tcpip_callback() to send mail
+ * from interrupt context, e.g. like this:
+ *    struct smtp_send_request *req; (to be filled)
+ *    tcpip_callback_with_block(smtp_send_mail_int, (void*)req, 0);
+ *
+ * For member description, see parameter description of smtp_send_mail().
+ * When using with tcpip_callback, this structure has to stay allocated
+ * (e.g. using mem_malloc/mem_free) until its 'callback_fn' is called.
+ */
+struct smtp_send_request {
+  const char *from;
+  const char* to;
+  const char* subject;
+  const char* body;
+  smtp_result_fn callback_fn;
+  void* callback_arg;
+  /** If this is != 0, data is *not* copied into an extra buffer
+   * but used from the pointers supplied in this struct.
+   * This means less memory usage, but data must stay untouched until
+   * the callback function is called. */
+  u8_t static_data;
+};
+
+
+#if SMTP_BODYDH
+
+#ifndef SMTP_BODYDH_BUFFER_SIZE
+#define SMTP_BODYDH_BUFFER_SIZE 256
+#endif /* SMTP_BODYDH_BUFFER_SIZE */
+
+struct smtp_bodydh {
+  u16_t state;
+  u16_t length; /* Length of content in buffer */
+  char buffer[SMTP_BODYDH_BUFFER_SIZE]; /* buffer for generated content */
+#ifdef SMTP_BODYDH_USER_SIZE
+  u8_t user[SMTP_BODYDH_USER_SIZE];
+#endif /* SMTP_BODYDH_USER_SIZE */
+};
+
+enum bdh_retvals_e {
+  BDH_DONE = 0,
+  BDH_WORKING
+};
+
+/** Prototype of an smtp body callback function
+ * It receives a struct smtp_bodydh, and a buffer to write data,
+ * must return BDH_WORKING to be called again and BDH_DONE when
+ * it has finished processing. This one tries to fill one TCP buffer with
+ * data, your function will be repeatedly called until that happens; so if you
+ * know you'll be taking too long to serve your request, pause once in a while
+ * by writing length=0 to avoid hogging system resources
+ *
+ * @param arg argument specified when initiating the email
+ * @param smtp_bodydh state handling + buffer structure
+ */
+typedef int (*smtp_bodycback_fn)(void *arg, struct smtp_bodydh *bodydh);
+
+err_t smtp_send_mail_bodycback(const char *from, const char* to, const char* subject,
+                     smtp_bodycback_fn bodycback_fn, smtp_result_fn callback_fn, void* callback_arg);
+
+#endif /* SMTP_BODYDH */
+
+
+err_t smtp_set_server_addr(const char* server);
+void smtp_set_server_port(u16_t port);
+#if LWIP_ALTCP && LWIP_ALTCP_TLS
+struct altcp_tls_config;
+void smtp_set_tls_config(struct altcp_tls_config *tls_config);
+#endif
+err_t smtp_set_auth(const char* username, const char* pass);
+err_t smtp_send_mail(const char *from, const char* to, const char* subject, const char* body,
+                     smtp_result_fn callback_fn, void* callback_arg);
+err_t smtp_send_mail_static(const char *from, const char* to, const char* subject, const char* body,
+                     smtp_result_fn callback_fn, void* callback_arg);
+void smtp_send_mail_int(void *arg);
+#ifdef LWIP_DEBUG
+const char* smtp_result_str(u8_t smtp_result);
+#endif
+
+#endif /* LWIP_HDR_APPS_SMTP_H */