SMTP client library. More...

#include <sys/types.h>
#include <stddef.h>
#include <stdio.h>

Include dependency graph for smtp.h:

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Data Structures
struct	smtp_command

struct	str_getdelimfd

Macros
#define	SIZE_MAX ((size_t)(-1))

Enumerations
enum	smtp_status_code { SMTP_STATUS_OK = 0, SMTP_STATUS_NOMEM = 1, SMTP_STATUS_CONNECT = 2, SMTP_STATUS_HANDSHAKE = 3, SMTP_STATUS_AUTH = 4, SMTP_STATUS_SEND = 5, SMTP_STATUS_RECV = 6, SMTP_STATUS_CLOSE = 7, SMTP_STATUS_SERVER_RESPONSE = 8, SMTP_STATUS_PARAM = 9, SMTP_STATUS_FILE = 10, SMTP_STATUS_DATE = 11, SMTP_STATUS__LAST }

enum	smtp_address_type { SMTP_ADDRESS_FROM = 0, SMTP_ADDRESS_TO = 1, SMTP_ADDRESS_CC = 2, SMTP_ADDRESS_BCC = 3 }

enum	smtp_connection_security { SMTP_SECURITY_STARTTLS = 0, SMTP_SECURITY_TLS = 1, SMTP_SECURITY_NONE = 2 }

enum	smtp_authentication_method { SMTP_AUTH_CRAM_MD5 = 0, SMTP_AUTH_NONE = 1, SMTP_AUTH_PLAIN = 2, SMTP_AUTH_LOGIN = 3 }

enum	smtp_flag { SMTP_DEBUG = 1 << 0, SMTP_NO_CERT_VERIFY = 1 << 1 }

enum	smtp_result_code { SMTP_INTERNAL_ERROR = -1, SMTP_READY = 220, SMTP_CLOSE = 221, SMTP_AUTH_SUCCESS = 235, SMTP_DONE = 250, SMTP_AUTH_CONTINUE = 334, SMTP_BEGIN_MAIL = 354 }

enum	str_getdelim_retcode { STRING_GETDELIMFD_ERROR = -1, STRING_GETDELIMFD_NEXT = 0, STRING_GETDELIMFD_DONE = 1 }

Functions
enum smtp_status_code	smtp_open (const char const server, const char const port, enum smtp_connection_security connection_security, enum smtp_flag flags, const char const cafile, struct smtp *smtp)

enum smtp_status_code	smtp_auth (struct smtp const smtp, enum smtp_authentication_method auth_method, const char const user, const char *const pass)

enum smtp_status_code	smtp_mail (struct smtp const smtp, const char const body)

enum smtp_status_code	smtp_close (struct smtp *smtp)

enum smtp_status_code	smtp_status_code_get (const struct smtp *const smtp)

enum smtp_status_code	smtp_status_code_clear (struct smtp *const smtp)

enum smtp_status_code	smtp_status_code_set (struct smtp *const smtp, enum smtp_status_code new_status_code)

const char *	smtp_status_code_errstr (enum smtp_status_code status_code)

enum smtp_status_code	smtp_header_add (struct smtp const smtp, const char const key, const char *const value)

void	smtp_header_clear_all (struct smtp *const smtp)

enum smtp_status_code	smtp_address_add (struct smtp const smtp, enum smtp_address_type type, const char const email, const char *const name)

void	smtp_address_clear_all (struct smtp *const smtp)

enum smtp_status_code	smtp_attachment_add_path (struct smtp const smtp, const char const name, const char *const path)

enum smtp_status_code	smtp_attachment_add_fp (struct smtp const smtp, const char const name, FILE *fp)

enum smtp_status_code	smtp_attachment_add_mem (struct smtp const smtp, const char const name, const void *const data, size_t datasz)

void	smtp_attachment_clear_all (struct smtp *const smtp)

Detailed Description

SMTP client library.

Author: James Humphrey (mail@.nosp@m.somn.nosp@m.isoft.nosp@m..com)

Version: 1.00

This SMTP client library allows the user to send emails to an SMTP server. The user can include custom headers and MIME attachments.

This software has been placed into the public domain using CC0.

Definition in file smtp.h.

Macro Definition Documentation

◆ SIZE_MAX

#define SIZE_MAX ((size_t)(-1))

Enumeration Type Documentation

◆ smtp_address_type

enum smtp_address_type

Address source and destination types.

Enumerator
SMTP_ADDRESS_FROM	From address.
SMTP_ADDRESS_TO	To address.
SMTP_ADDRESS_CC	Copy address.
SMTP_ADDRESS_BCC	Blind copy address. Recipients should not see any of the BCC addresses when they receive their email. However, some SMTP server implementations may copy this information into the mail header, so do not assume that this will always get hidden. If the BCC addresses must not get shown to the receivers, then send one separate email to each BCC party and add the TO and CC addresses manually as a header property using smtp_header_add instead of as an address using smtp_address_add.

Definition at line 105 of file smtp.h.

                       {
   SMTP_ADDRESS_FROM = 0,
 
   SMTP_ADDRESS_TO   = 1,
 
   SMTP_ADDRESS_CC   = 2,
 
   SMTP_ADDRESS_BCC  = 3
 };

◆ smtp_authentication_method

enum smtp_authentication_method

List of supported methods for authenticating a mail user account on the server.

Enumerator
SMTP_AUTH_CRAM_MD5	Use HMAC-MD5.
SMTP_AUTH_NONE	No authentication required. Some servers support this option if connecting locally.
SMTP_AUTH_PLAIN	Authenticate using base64 user and password.
SMTP_AUTH_LOGIN	Another base64 authentication method, similar to SMTP_AUTH_PLAIN.

Definition at line 170 of file smtp.h.

                                {
 #ifdef SMTP_OPENSSL
 
   SMTP_AUTH_CRAM_MD5 = 0,
 #endif /* SMTP_OPENSSL */
 
   SMTP_AUTH_NONE     = 1,
 
   SMTP_AUTH_PLAIN    = 2,
 
   SMTP_AUTH_LOGIN    = 3
 };

◆ smtp_connection_security

enum smtp_connection_security

Connect to the SMTP server using either an unencrypted socket or TLS encryption.

Enumerator

SMTP_SECURITY_STARTTLS

First connect without encryption, then negotiate an encrypted connection by issuing a STARTTLS command.

Typically used when connecting to a mail server on port 25 or 587.

SMTP_SECURITY_TLS

Use TLS when initially connecting to server.

Typically used when connecting to a mail server on port 465.

SMTP_SECURITY_NONE

Do not use TLS encryption.

Not recommended unless connecting to the SMTP server locally.

Definition at line 140 of file smtp.h.

                              {
 #ifdef SMTP_OPENSSL
 
   SMTP_SECURITY_STARTTLS = 0,
 
   SMTP_SECURITY_TLS      = 1,
 #endif /* SMTP_OPENSSL */
 
   SMTP_SECURITY_NONE     = 2
 };

◆ smtp_flag

enum smtp_flag

Special flags defining certain behaviors for the SMTP client context.

Enumerator

SMTP_DEBUG

Print client and server communication on stderr.

SMTP_NO_CERT_VERIFY

Do not verify TLS certificate.

By default, the TLS handshake function will check if a certificate has expired or if using a self-signed certificate. Either of those conditions will cause the connection to fail. This option allows the connection to proceed even if those checks fail.

Definition at line 198 of file smtp.h.

               {
   SMTP_DEBUG          = 1 << 0,
 
   SMTP_NO_CERT_VERIFY = 1 << 1
 };

◆ smtp_result_code

enum smtp_result_code

SMTP codes returned by the server and parsed by the client.

Enumerator
SMTP_INTERNAL_ERROR	Client error code which does not get set by the server.
SMTP_READY	Returned when ready to begin processing next step.
SMTP_CLOSE	Returned in response to QUIT.
SMTP_AUTH_SUCCESS	Returned if client successfully authenticates.
SMTP_DONE	Returned when some commands successfully complete.
SMTP_AUTH_CONTINUE	Returned for some multi-line authentication mechanisms where this code indicates the next stage in the authentication step.
SMTP_BEGIN_MAIL	Returned in response to DATA command.

Definition at line 483 of file smtp.h.

                      {
   SMTP_INTERNAL_ERROR =  -1,
 
   SMTP_READY          = 220,
 
   SMTP_CLOSE          = 221,
 
   SMTP_AUTH_SUCCESS   = 235,
 
   SMTP_DONE           = 250,
 
   SMTP_AUTH_CONTINUE  = 334,
 
   SMTP_BEGIN_MAIL     = 354
 };

◆ smtp_status_code

enum smtp_status_code

Status codes indicating success or failure from calling any of the SMTP library functions.

This code gets returned by all functions in this header.

Enumerator
SMTP_STATUS_OK	Successful operation completed.
SMTP_STATUS_NOMEM	Memory allocation failed.
SMTP_STATUS_CONNECT	Failed to connect to the mail server.
SMTP_STATUS_HANDSHAKE	Failed to handshake or negotiate a TLS connection with the server.
SMTP_STATUS_AUTH	Failed to authenticate with the given credentials.
SMTP_STATUS_SEND	Failed to send bytes to the server.
SMTP_STATUS_RECV	Failed to receive bytes from the server.
SMTP_STATUS_CLOSE	Failed to properly close a connection.
SMTP_STATUS_SERVER_RESPONSE	SMTP server sent back an unexpected status code.
SMTP_STATUS_PARAM	Invalid parameter.
SMTP_STATUS_FILE	Failed to open or read a local file.
SMTP_STATUS_DATE	Failed to get the local date and time.
SMTP_STATUS__LAST	Indicates the last status code in the enumeration, useful for bounds checking. Not a valid status code.

Definition at line 32 of file smtp.h.

                      {
   SMTP_STATUS_OK              = 0,
 
   SMTP_STATUS_NOMEM           = 1,
 
   SMTP_STATUS_CONNECT         = 2,
 
   SMTP_STATUS_HANDSHAKE       = 3,
 
   SMTP_STATUS_AUTH            = 4,
 
   SMTP_STATUS_SEND            = 5,
 
   SMTP_STATUS_RECV            = 6,
 
   SMTP_STATUS_CLOSE           = 7,
 
   SMTP_STATUS_SERVER_RESPONSE = 8,
 
   SMTP_STATUS_PARAM           = 9,
 
   SMTP_STATUS_FILE            = 10,
 
   SMTP_STATUS_DATE            = 11,
 
   SMTP_STATUS__LAST
 };

◆ str_getdelim_retcode

enum str_getdelim_retcode

Return codes for the getdelim interface which allows the caller to check if more delimited lines can get processed.

Enumerator
STRING_GETDELIMFD_ERROR	An error occurred during the getdelim processing.
STRING_GETDELIMFD_NEXT	Found a new line and can process more lines in the next call.
STRING_GETDELIMFD_DONE	Found a new line and unable to read any more lines at this time.

Definition at line 551 of file smtp.h.

                          {
   STRING_GETDELIMFD_ERROR = -1,
 
   STRING_GETDELIMFD_NEXT  =  0,
 
   STRING_GETDELIMFD_DONE  =  1
 };

Function Documentation

◆ smtp_address_add()

enum smtp_status_code smtp_address_add	(	struct smtp *const	smtp,
		enum smtp_address_type	type,
		const char *const	email,
		const char *const	name
	)

Add a FROM, TO, CC, or BCC address destination to this SMTP context.

Note: Some SMTP servers may reject over 100 recipients.

Parameters

[in]	smtp	SMTP client context.
[in]	type	See smtp_address_type.
[in]	email	The email address of the party. Must consist only of printable characters excluding the angle brackets (<) and (>).
[in]	name	Name or description of the party. Must consist only of printable characters, excluding the quote characters. If set to NULL or empty string, no name will get associated with this email.

Returns: See smtp_status_code.

Definition at line 3347 of file smtp.c.

References smtp::address_list, smtp_address::email, smtp_address::name, smtp::num_address, smtp_address_validate_email(), smtp_address_validate_name(), smtp_reallocarray(), smtp_si_add_size_t(), smtp_status_code_set(), SMTP_STATUS_NOMEM, SMTP_STATUS_OK, SMTP_STATUS_PARAM, smtp_strdup(), smtp::status_code, and smtp_address::type.

Referenced by SMTPMail::address_add(), mailx_send(), smtp_address_add_check(), and test_nossl_smtp().

                                         {
   struct smtp_address *new_address_list;
   struct smtp_address *new_address;
   size_t num_address_inc;
 
   if(smtp->status_code != SMTP_STATUS_OK){
     return smtp->status_code;
   }
 
   if(smtp_address_validate_email(email) < 0){
     return smtp_status_code_set(smtp, SMTP_STATUS_PARAM);
   }
 
   if(name && smtp_address_validate_name(name) < 0){
     return smtp_status_code_set(smtp, SMTP_STATUS_PARAM);
   }
 
   if(smtp_si_add_size_t(smtp->num_address, 1, &num_address_inc)){
     return smtp_status_code_set(smtp, SMTP_STATUS_NOMEM);
   }
 
   new_address_list = smtp_reallocarray(smtp->address_list,
                                        num_address_inc,
                                        sizeof(*new_address_list));
   if(new_address_list == NULL){
     return smtp_status_code_set(smtp, SMTP_STATUS_NOMEM);
   }
   new_address = &new_address_list[smtp->num_address];
 
   smtp->address_list = new_address_list;
 
   new_address->type = type;
   new_address->email = smtp_strdup(email);
   if(name){
     new_address->name = smtp_strdup(name);
   }
   else{
     new_address->name = NULL;
   }
   if(new_address->email == NULL ||
      (new_address->name == NULL && name)){
     free(new_address->email);
     free(new_address->name);
     return smtp_status_code_set(smtp, SMTP_STATUS_NOMEM);
   }
   smtp->num_address = num_address_inc;
 
   return smtp->status_code;
 }

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◆ smtp_address_clear_all()

void smtp_address_clear_all ( struct smtp *const smtp )

Free all memory related to the address list.

Parameters

[in] smtp SMTP client context.

Definition at line 3401 of file smtp.c.

References smtp::address_list, smtp_address::email, smtp_address::name, and smtp::num_address.

Referenced by SMTPMail::address_clear_all(), smtp_close(), smtp_func_test_all_address(), and smtp_func_test_all_names().

                                                {
   size_t i;
   struct smtp_address *address;
 
   for(i = 0; i < smtp->num_address; i++){
     address = &smtp->address_list[i];
     free(address->email);
     free(address->name);
   }
   free(smtp->address_list);
   smtp->address_list = NULL;
   smtp->num_address = 0;
 }

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◆ smtp_attachment_add_fp()

enum smtp_status_code smtp_attachment_add_fp	(	struct smtp *const	smtp,
		const char *const	name,
		FILE *	fp
	)

Add an attachment using a file pointer.

See smtp_attachment_add_mem for more details.

Parameters

[in]	smtp	SMTP client context.
[in]	name	Filename of the attachment shown to recipients. Must consist only of printable ASCII characters, excluding the quote characters (') and (").
[in]	fp	File pointer already opened by the caller.

Returns: See smtp_status_code.

Definition at line 3439 of file smtp.c.

References smtp_attachment_add_mem(), smtp_ffile_get_contents(), smtp_status_code_set(), SMTP_STATUS_FILE, SMTP_STATUS_NOMEM, SMTP_STATUS_OK, and smtp::status_code.

Referenced by SMTPMail::attachment_add_fp(), smtp_func_test_attachment_fp(), and test_failure_attachment_add().

                                 {
   char *data;
   size_t bytes_read;
 
   if(smtp->status_code != SMTP_STATUS_OK){
     return smtp->status_code;
   }
 
   errno = 0;
   if((data = smtp_ffile_get_contents(fp, &bytes_read)) == NULL){
     if(errno == ENOMEM){
       return smtp_status_code_set(smtp, SMTP_STATUS_NOMEM);
     }
     return smtp_status_code_set(smtp, SMTP_STATUS_FILE);
   }
   smtp_attachment_add_mem(smtp, name, data, bytes_read);
   free(data);
   return smtp->status_code;
 }

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◆ smtp_attachment_add_mem()

enum smtp_status_code smtp_attachment_add_mem	(	struct smtp *const	smtp,
		const char *const	name,
		const void *const	data,
		size_t	datasz
	)

Add a MIME attachment to this SMTP context with the data retrieved from memory.

The attachment data will get base64 encoded before sending to the server.

Parameters

[in]	smtp	SMTP client context.
[in]	name	Filename of the attachment shown to recipients. Must consist only of printable ASCII characters, excluding the quote characters (') and (").
[in]	data	Raw attachment data stored in memory.
[in]	datasz	Number of bytes in `data`, or -1 if data null-terminated.

Returns: See smtp_status_code.

Definition at line 3462 of file smtp.c.

References smtp::attachment_list, smtp_attachment::b64_data, smtp_attachment::name, smtp::num_attachment, SIZE_MAX, smtp_attachment_validate_name(), smtp_base64_encode(), smtp_chunk_split(), SMTP_LINE_MAX, smtp_reallocarray(), smtp_si_add_size_t(), smtp_status_code_set(), SMTP_STATUS_NOMEM, SMTP_STATUS_OK, SMTP_STATUS_PARAM, smtp_strdup(), smtp::status_code, and strlen.

Referenced by SMTPMail::attachment_add_mem(), smtp_attachment_add_fp(), smtp_attachment_add_path(), smtp_func_test_attachment_long_text(), smtp_func_test_attachment_mem(), test_failure_attachment_add(), and test_smtp_open_default().

                                       {
   size_t num_attachment_inc;
   struct smtp_attachment *new_attachment_list;
   struct smtp_attachment *new_attachment;
   char *b64_encode;
 
   if(smtp->status_code != SMTP_STATUS_OK){
     return smtp->status_code;
   }
 
   if(smtp_attachment_validate_name(name) < 0){
     return smtp_status_code_set(smtp, SMTP_STATUS_PARAM);
   }
 
   if(datasz == SIZE_MAX){
     datasz = strlen(data);
   }
 
   if(smtp_si_add_size_t(smtp->num_attachment, 1, &num_attachment_inc) ||
      (new_attachment_list = smtp_reallocarray(
                               smtp->attachment_list,
                               num_attachment_inc,
                               sizeof(*new_attachment_list))) == NULL){
     return smtp_status_code_set(smtp, SMTP_STATUS_NOMEM);
   }
   smtp->attachment_list = new_attachment_list;
   new_attachment = &new_attachment_list[smtp->num_attachment];
 
   new_attachment->name = smtp_strdup(name);
   b64_encode = smtp_base64_encode(data, datasz);
   if(new_attachment->name == NULL || b64_encode == NULL){
     free(new_attachment->name);
     free(b64_encode);
     return smtp_status_code_set(smtp, SMTP_STATUS_NOMEM);
   }
 
   new_attachment->b64_data = smtp_chunk_split(b64_encode,
                                               SMTP_LINE_MAX,
                                               "\r\n");
   free(b64_encode);
   if(new_attachment->b64_data == NULL){
     free(new_attachment->name);
     return smtp_status_code_set(smtp, SMTP_STATUS_NOMEM);
   }
 
   smtp->num_attachment = num_attachment_inc;
   return smtp->status_code;
 }

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◆ smtp_attachment_add_path()

enum smtp_status_code smtp_attachment_add_path	(	struct smtp *const	smtp,
		const char *const	name,
		const char *const	path
	)

Add a file attachment from a path.

See smtp_attachment_add_mem for more details.

Parameters

[in]	smtp	SMTP client context.
[in]	name	Filename of the attachment shown to recipients. Must consist only of printable ASCII characters, excluding the quote characters (') and (").
[in]	path	Path to file.

Returns: See smtp_status_code.

Definition at line 3416 of file smtp.c.

References smtp_attachment_add_mem(), smtp_file_get_contents(), smtp_status_code_set(), SMTP_STATUS_FILE, SMTP_STATUS_NOMEM, SMTP_STATUS_OK, and smtp::status_code.

Referenced by SMTPMail::attachment_add_path(), mailx_send(), smtp_func_test_attachment_path(), smtp_func_test_attachment_pdf(), smtp_func_test_gmail_attachment(), and test_failure_attachment_add().

                                                 {
   char *data;
   size_t bytes_read;
 
   if(smtp->status_code != SMTP_STATUS_OK){
     return smtp->status_code;
   }
 
   errno = 0;
   if((data = smtp_file_get_contents(path, &bytes_read)) == NULL){
     if(errno == ENOMEM){
       return smtp_status_code_set(smtp, SMTP_STATUS_NOMEM);
     }
     return smtp_status_code_set(smtp, SMTP_STATUS_FILE);
   }
   smtp_attachment_add_mem(smtp, name, data, bytes_read);
   free(data);
   return smtp->status_code;
 }

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◆ smtp_attachment_clear_all()

void smtp_attachment_clear_all ( struct smtp *const smtp )

Remove all attachments from the SMTP client context.

Parameters

[in] smtp SMTP client context.

Definition at line 3515 of file smtp.c.

References smtp::attachment_list, smtp_attachment::b64_data, smtp_attachment::name, and smtp::num_attachment.

Referenced by SMTPMail::attachment_clear_all(), and smtp_close().

                                                   {
   size_t i;
   struct smtp_attachment *attachment;
 
   for(i = 0; i < smtp->num_attachment; i++){
     attachment = &smtp->attachment_list[i];
     free(attachment->name);
     free(attachment->b64_data);
   }
   free(smtp->attachment_list);
   smtp->attachment_list = NULL;
   smtp->num_attachment = 0;
 }

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◆ smtp_auth()

enum smtp_status_code smtp_auth	(	struct smtp *const	smtp,
		enum smtp_authentication_method	auth_method,
		const char *const	user,
		const char *const	pass
	)

Authenticate the user using one of the methods listed in smtp_authentication_method.

Parameters

[in]	smtp	SMTP client context.
[in]	auth_method	See smtp_authentication_method.
[in]	user	SMTP user name.
[in]	pass	SMTP password.

Returns: See smtp_status_code.

Definition at line 3026 of file smtp.c.

References SMTP_AUTH_CRAM_MD5, smtp_auth_cram_md5(), SMTP_AUTH_LOGIN, smtp_auth_login(), SMTP_AUTH_NONE, SMTP_AUTH_PLAIN, smtp_auth_plain(), SMTP_STATUS_AUTH, smtp_status_code_set(), SMTP_STATUS_OK, SMTP_STATUS_PARAM, and smtp::status_code.

Referenced by SMTPMail::auth(), mailx_send(), and smtp_auth_check().

                                  {
   int auth_rc;
 
   if(smtp->status_code != SMTP_STATUS_OK){
     return smtp->status_code;
   }
 
   if(auth_method == SMTP_AUTH_PLAIN){
     auth_rc = smtp_auth_plain(smtp, user, pass);
   }
   else if(auth_method == SMTP_AUTH_LOGIN){
     auth_rc = smtp_auth_login(smtp, user, pass);
   }
 #ifdef SMTP_OPENSSL
   else if(auth_method == SMTP_AUTH_CRAM_MD5){
     auth_rc = smtp_auth_cram_md5(smtp, user, pass);
   }
 #endif /* SMTP_OPENSSL */
   else if(auth_method == SMTP_AUTH_NONE){
     auth_rc = 0;
   }
   else{
     return smtp_status_code_set(smtp, SMTP_STATUS_PARAM);
   }
 
   if(auth_rc < 0){
     return smtp_status_code_set(smtp, SMTP_STATUS_AUTH);
   }
 
   return smtp->status_code;
 }

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◆ smtp_close()

enum smtp_status_code smtp_close ( struct smtp * smtp )

Close the SMTP connection and frees all resources held by the SMTP context.

Parameters

[in] smtp SMTP client context.

Returns: See smtp_status_code.

Definition at line 3168 of file smtp.c.

References close, smtp::flags, smtp::gdfd, smtp_address_clear_all(), smtp_attachment_clear_all(), SMTP_FLAG_INVALID_MEMORY, smtp_header_clear_all(), smtp_puts(), SMTP_STATUS_CLOSE, smtp_status_code_set(), SMTP_STATUS_OK, smtp_str_getdelimfd_free(), smtp::sock, smtp::status_code, smtp::tls, smtp::tls_ctx, and smtp::tls_on.

Referenced by SMTPMail::close(), mailx_send(), smtp_close_check(), smtp_func_test_server_secureserver(), and test_nossl_smtp().

                              {
   enum smtp_status_code status_code;
 
   status_code = smtp->status_code;
 
   if(smtp->flags == SMTP_FLAG_INVALID_MEMORY){
     return status_code;
   }
 
   if(smtp->sock != -1){
     /*
      * Do not error out if this fails because we still need to free the
      * SMTP client resources.
      */
     smtp->status_code = SMTP_STATUS_OK;
     smtp_puts(smtp, "QUIT\r\n");
 
 #ifdef SMTP_OPENSSL
     if(smtp->tls_on){
       SSL_free(smtp->tls);
       SSL_CTX_free(smtp->tls_ctx);
     }
 #endif /* SMTP_OPENSSL */
 
 #ifdef SMTP_IS_WINDOWS
     closesocket(smtp->sock);
     WSACleanup();
 #else /* POSIX */
     if(close(smtp->sock) < 0){
       if(smtp->status_code == SMTP_STATUS_OK){
         smtp_status_code_set(smtp, SMTP_STATUS_CLOSE);
       }
     }
 #endif /* SMTP_IS_WINDOWS */
   }
 
   smtp_str_getdelimfd_free(&smtp->gdfd);
   smtp_header_clear_all(smtp);
   smtp_address_clear_all(smtp);
   smtp_attachment_clear_all(smtp);
   if(status_code == SMTP_STATUS_OK){
     status_code = smtp->status_code;
   }
   free(smtp);
 
   return status_code;
 }

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◆ smtp_header_add()

enum smtp_status_code smtp_header_add	(	struct smtp *const	smtp,
		const char *const	key,
		const char *const	value
	)

Add a key/value header to the header list in the SMTP context.

If adding a header with an existing key, this will insert instead of replacing the existing header. See smtp_header_clear_all.

See smtp_mail when overriding the default 'Content-Type' header.

Parameters

[in]	smtp	SMTP client context.
[in]	key	Key name for new header. It must consist only of printable US-ASCII characters except colon.
[in]	value	Value for new header. It must consist only of printable US-ASCII, space, or horizontal tab. If set to NULL, this will prevent the header from printing out.

Returns: See smtp_status_code.

Definition at line 3278 of file smtp.c.

References smtp::header_list, smtp_header::key, smtp::num_headers, smtp_header_cmp(), smtp_header_key_validate(), smtp_header_value_validate(), smtp_reallocarray(), smtp_si_add_size_t(), smtp_status_code_set(), SMTP_STATUS_NOMEM, SMTP_STATUS_OK, SMTP_STATUS_PARAM, smtp_strdup(), smtp::status_code, and smtp_header::value.

Referenced by SMTPMail::header_add(), mailx_send(), smtp_append_address_to_header(), smtp_header_add_check(), smtp_mail(), and test_nossl_smtp().

                                         {
   struct smtp_header *new_header_list;
   struct smtp_header *new_header;
   size_t num_headers_inc;
 
   if(smtp->status_code != SMTP_STATUS_OK){
     return smtp->status_code;
   }
 
   if(smtp_header_key_validate(key) < 0){
     return smtp_status_code_set(smtp, SMTP_STATUS_PARAM);
   }
 
   if(value && smtp_header_value_validate(value) < 0){
     return smtp_status_code_set(smtp, SMTP_STATUS_PARAM);
   }
 
   if(smtp_si_add_size_t(smtp->num_headers, 1, &num_headers_inc) ||
      (new_header_list = smtp_reallocarray(
                           smtp->header_list,
                           num_headers_inc,
                           sizeof(*smtp->header_list))) == NULL){
     return smtp_status_code_set(smtp, SMTP_STATUS_NOMEM);
   }
   smtp->header_list = new_header_list;
   new_header = &smtp->header_list[smtp->num_headers];
 
   new_header->key = smtp_strdup(key);
   if(value){
     new_header->value = smtp_strdup(value);
   }
   else{
     new_header->value = NULL;
   }
   if(new_header->key == NULL ||
      (new_header->value == NULL && value)){
     free(new_header->key);
     free(new_header->value);
     return smtp_status_code_set(smtp, SMTP_STATUS_NOMEM);
   }
 
   smtp->num_headers = num_headers_inc;
 
   qsort(smtp->header_list,
         smtp->num_headers,
         sizeof(*smtp->header_list),
         smtp_header_cmp);
 
   return smtp->status_code;
 }

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◆ smtp_header_clear_all()

void smtp_header_clear_all ( struct smtp *const smtp )

Free all memory related to email headers.

Parameters

[in] smtp SMTP client context.

Definition at line 3332 of file smtp.c.

References smtp::header_list, smtp_header::key, smtp::num_headers, and smtp_header::value.

Referenced by SMTPMail::header_clear_all(), smtp_close(), smtp_func_test_all_address(), smtp_func_test_all_names(), smtp_func_test_all_nodebug(), smtp_func_test_header_custom_date(), smtp_func_test_header_long(), smtp_func_test_header_null_no_date(), smtp_func_test_html(), and smtp_func_test_html_with_plaintext().

                                               {
   size_t i;
   struct smtp_header *header;
 
   for(i = 0; i < smtp->num_headers; i++){
     header = &smtp->header_list[i];
     free(header->key);
     free(header->value);
   }
   free(smtp->header_list);
   smtp->header_list = NULL;
   smtp->num_headers = 0;
 }

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◆ smtp_mail()

enum smtp_status_code smtp_mail	(	struct smtp *const	smtp,
		const char *const	body
	)

Sends an email using the addresses, attachments, and headers defined in the current SMTP context.

The caller must call the smtp_open function prior to this.

The 'Date' header will automatically get generated here if it hasn't already been set using smtp_header_add.

If the application overrides the default 'Content-Type' header, then this function will output the body as raw data just below the email headers, and it will not output the attachments added using the smtp_attachment_add_* functions. In other words, the application must create its own MIME sections (if needed) when overriding the 'Content-Type' header.

Parameters

[in]	smtp	SMTP client context.
[in]	body	Null-terminated string to send in the email body.

Returns: See smtp_status_code.

Definition at line 3062 of file smtp.c.

References smtp::address_list, smtp::header_list, smtp::num_address, smtp::num_headers, SMTP_ADDRESS_CC, SMTP_ADDRESS_FROM, SMTP_ADDRESS_TO, smtp_append_address_to_header(), SMTP_BEGIN_MAIL, SMTP_DATE_MAX_SZ, smtp_date_rfc_2822(), SMTP_DONE, smtp_header_add(), smtp_header_exists(), smtp_mail_envelope_header(), smtp_print_email(), smtp_print_header(), smtp_puts(), smtp_read_and_parse_code(), smtp_set_read_timeout(), smtp_status_code_set(), SMTP_STATUS_DATE, SMTP_STATUS_OK, SMTP_STATUS_PARAM, SMTP_STATUS_SERVER_RESPONSE, smtp::status_code, and smtp_address::type.

Referenced by SMTPMail::mail(), mailx_send(), smtp_mail_check(), and test_nossl_smtp().

                                  {
   size_t i;
   int has_mail_from;
   struct smtp_address *address;
   char date[SMTP_DATE_MAX_SZ];
 
   if(smtp->status_code != SMTP_STATUS_OK){
     return smtp->status_code;
   }
 
   /* MAIL timeout 5 minutes. */
   smtp_set_read_timeout(smtp, 60 * 5);
   has_mail_from = 0;
   for(i = 0; i < smtp->num_address; i++){
     address = &smtp->address_list[i];
     if(address->type == SMTP_ADDRESS_FROM){
       if(smtp_mail_envelope_header(smtp,
                                    "MAIL FROM",
                                    address) != SMTP_STATUS_OK){
         return smtp->status_code;
       }
       has_mail_from = 1;
       break;
     }
   }
 
   if(!has_mail_from){
     return smtp_status_code_set(smtp, SMTP_STATUS_PARAM);
   }
 
   /* RCPT timeout 5 minutes. */
   smtp_set_read_timeout(smtp, 60 * 5);
 
   for(i = 0; i < smtp->num_address; i++){
     address = &smtp->address_list[i];
     if(address->type != SMTP_ADDRESS_FROM){
       if(smtp_mail_envelope_header(smtp,
                                    "RCPT TO",
                                    address) != SMTP_STATUS_OK){
         return smtp->status_code;
       }
     }
   }
 
   /* DATA timeout 2 minutes. */
   smtp_set_read_timeout(smtp, 60 * 2);
 
   if(smtp_puts(smtp, "DATA\r\n") != SMTP_STATUS_OK){
     return smtp->status_code;
   }
 
   /* 354 response to DATA must get returned before we can send the message. */
   if(smtp_read_and_parse_code(smtp) != SMTP_BEGIN_MAIL){
     return smtp_status_code_set(smtp, SMTP_STATUS_SERVER_RESPONSE);
   }
 
   if(!smtp_header_exists(smtp, "Date")){
     if(smtp_date_rfc_2822(date) < 0){
       return smtp_status_code_set(smtp, SMTP_STATUS_DATE);
     }
     if(smtp_header_add(smtp, "Date", date) != SMTP_STATUS_OK){
       return smtp->status_code;
     }
   }
 
   /* DATA block timeout 3 minutes. */
   smtp_set_read_timeout(smtp, 60 * 3);
 
   if(smtp_append_address_to_header(smtp,
                                    SMTP_ADDRESS_FROM,
                                    "From") != SMTP_STATUS_OK ||
      smtp_append_address_to_header(smtp,
                                    SMTP_ADDRESS_TO,
                                    "To") != SMTP_STATUS_OK ||
      smtp_append_address_to_header(smtp,
                                    SMTP_ADDRESS_CC,
                                    "Cc") != SMTP_STATUS_OK){
     return smtp->status_code;
   }
 
   for(i = 0; i < smtp->num_headers; i++){
     if(smtp_print_header(smtp, &smtp->header_list[i]) != SMTP_STATUS_OK){
       return smtp->status_code;
     }
   }
 
   if(smtp_print_email(smtp, body)){
     return smtp->status_code;
   }
 
   /* End of DATA segment. */
   if(smtp_puts(smtp, ".\r\n") != SMTP_STATUS_OK){
     return smtp->status_code;
   }
 
   /* DATA termination timeout 250 return code - 10 minutes. */
   smtp_set_read_timeout(smtp, 60 * 10);
   if(smtp_read_and_parse_code(smtp) != SMTP_DONE){
     return smtp_status_code_set(smtp, SMTP_STATUS_SERVER_RESPONSE);
   }
 
   return smtp->status_code;
 }

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◆ smtp_open()

enum smtp_status_code smtp_open	(	const char *const	server,
		const char *const	port,
		enum smtp_connection_security	connection_security,
		enum smtp_flag	flags,
		const char *const	cafile,
		struct smtp **	smtp
	)

Open a connection to an SMTP server and return the context.

After successfully connecting and performing a handshake with the SMTP server, this will return a valid SMTP client context that the application can use in the other library functions.

This always returns a valid SMTP client context even if the server connection or memory allocation fails. In this scenario, the error status will continue to propagate to future library calls for the SMTP context while in this failure mode.

This function will ignore the SIGPIPE signal. Applications that require a handler for that signal should set it up after calling this function.

Parameters

[in]	server	Server name or IP address.
[in]	port	Server port number.
[in]	connection_security	See smtp_connection_security.
[in]	flags	See smtp_flag.
[in]	cafile	Path to certificate file, or NULL to use certificates in the default path.
[out]	smtp	Pointer to a new SMTP context. When finished, the caller must free this context using smtp_close.

Returns: See smtp_status_code.

Definition at line 2987 of file smtp.c.

References smtp::cafile, calloc, str_getdelimfd::delim, smtp::flags, g_smtp_error, smtp::gdfd, str_getdelimfd::getdelimfd_read, smtp_connect(), smtp_initiate_handshake(), smtp_status_code_get(), smtp_status_code_set(), SMTP_STATUS_CONNECT, SMTP_STATUS_HANDSHAKE, SMTP_STATUS_OK, smtp_str_getdelimfd_read(), smtp::sock, smtp::status_code, and str_getdelimfd::user_data.

Referenced by mailx_send(), SMTPMail::open(), smtp_func_test_all_address(), smtp_func_test_all_body(), smtp_func_test_all_names(), smtp_func_test_all_nodebug(), smtp_func_test_all_status_code_get(), smtp_func_test_all_write(), smtp_func_test_attachment_fp(), smtp_func_test_attachment_long_text(), smtp_func_test_attachment_mem(), smtp_func_test_attachment_path(), smtp_func_test_attachment_pdf(), smtp_func_test_gmail_attachment(), smtp_func_test_header_custom_date(), smtp_func_test_header_long(), smtp_func_test_header_null_no_date(), smtp_func_test_html(), smtp_func_test_html_with_plaintext(), smtp_func_test_send_email(), smtp_func_test_server_secureserver(), test_failure_address_add(), test_failure_attachment_add(), test_failure_close(), test_failure_header_add(), test_failure_misc(), test_failure_open(), test_failure_status_code_set(), test_failure_timeout(), test_nossl_smtp(), and test_smtp_open_default().

                              {
   struct smtp *snew;
 
   if((snew = calloc(1, sizeof(**smtp))) == NULL){
     *smtp = &g_smtp_error;
     return smtp_status_code_get(*smtp);
   }
   *smtp = snew;
 
   snew->flags                = flags;
   snew->sock                 = -1;
   snew->gdfd.delim           = '\n';
   snew->gdfd.getdelimfd_read = smtp_str_getdelimfd_read;
   snew->gdfd.user_data       = snew;
   snew->cafile               = cafile;
 
 #ifndef SMTP_IS_WINDOWS
   signal(SIGPIPE, SIG_IGN);
 #endif /* !(SMTP_IS_WINDOWS) */
 
   if(smtp_connect(snew, server, port) < 0){
     return smtp_status_code_set(*smtp, SMTP_STATUS_CONNECT);
   }
 
   if(smtp_initiate_handshake(snew,
                              server,
                              connection_security) != SMTP_STATUS_OK){
     return smtp_status_code_set(*smtp, SMTP_STATUS_HANDSHAKE);
   }
 
   return snew->status_code;
 }

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◆ smtp_status_code_clear()

enum smtp_status_code smtp_status_code_clear ( struct smtp *const smtp )

Clear the current error code set in the SMTP client context.

Parameters

[in,out] smtp SMTP client context.

Returns: Previous error code before clearing.

Definition at line 3222 of file smtp.c.

References smtp_status_code_get(), smtp_status_code_set(), and SMTP_STATUS_OK.

Referenced by smtp_func_test_all_address(), smtp_func_test_all_status_code_get(), test_failure_address_add(), test_failure_attachment_add(), test_failure_header_add(), and test_failure_status_code_set().

                                                {
   enum smtp_status_code old_status;
 
   old_status = smtp_status_code_get(smtp);
   smtp_status_code_set(smtp, SMTP_STATUS_OK);
   return old_status;
 }

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◆ smtp_status_code_errstr()

const char* smtp_status_code_errstr ( enum smtp_status_code status_code )

Convert a standard SMTP client status code to a descriptive string.

Parameters

[in] status_code Status code returned from one of the other library functions.

Returns: String containing a description of the status_code. The caller must not free or modify this string.

Definition at line 3241 of file smtp.c.

References SMTP_STATUS__LAST.

Referenced by mailx_send(), smtp_unit_test_smtp_status_code_errstr(), and SMTPMailException::what().

                                                           {
   const char *const status_code_err_str[] = {
     /* SMTP_STATUS_OK */
     "Success",
     /* SMTP_STATUS_NOMEM */
     "Memory allocation failed",
     /* SMTP_STATUS_CONNECT */
     "Failed to connect to the mail server",
     /* SMTP_STATUS_HANDSHAKE */
     "Failed to handshake or negotiate a TLS connection with the server",
     /* SMTP_STATUS_AUTH */
     "Failed to authenticate with the given credentials",
     /* SMTP_STATUS_SEND */
     "Failed to send bytes to the server",
     /* SMTP_STATUS_RECV */
     "Failed to receive bytes from the server",
     /* SMTP_STATUS_CLOSE */
     "Failed to properly close a connection",
     /* SMTP_STATUS_SERVER_RESPONSE */
     "SMTP server sent back an unexpected status code",
     /* SMTP_STATUS_PARAM */
     "Invalid parameter",
     /* SMTP_STATUS_FILE */
     "Failed to read or open a local file",
     /* SMTP_STATUS_DATE */
     "Failed to get the local date and time",
     /* SMTP_STATUS__LAST */
     "Unknown error"
   };
 
   if((unsigned)status_code > SMTP_STATUS__LAST){
     status_code = SMTP_STATUS__LAST;
   }
   return status_code_err_str[status_code];
 }

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◆ smtp_status_code_get()

enum smtp_status_code smtp_status_code_get ( const struct smtp *const smtp )

Get the current status/error code.

Parameters

[in] smtp SMTP client context.

Returns: See smtp_status_code.

Definition at line 3217 of file smtp.c.

References smtp::status_code.

Referenced by smtp_func_test_all_status_code_get(), smtp_open(), smtp_status_code_clear(), SMTPMail::status_code_get(), and test_failure_status_code_set().

                                                    {
   return smtp->status_code;
 }

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◆ smtp_status_code_set()

enum smtp_status_code smtp_status_code_set	(	struct smtp *const	smtp,
		enum smtp_status_code	new_status_code
	)

Set the error status of the SMTP client context and return the same code.

This allows the caller to clear an error status to SMTP_STATUS_OK so that previous errors will stop propagating. However, this will only work correctly for clearing the SMTP_STATUS_PARAM and SMTP_STATUS_FILE errors. Do not use this to clear any other error codes.

Deprecated:: Use smtp_status_code_clear instead.

Parameters

[in]	smtp	SMTP client context.
[in]	new_status_code	See smtp_status_code.

Returns: See smtp_status_code.

Definition at line 3231 of file smtp.c.

References SMTP_STATUS__LAST, SMTP_STATUS_PARAM, and smtp::status_code.

Referenced by smtp_address_add(), smtp_append_address_to_header(), smtp_attachment_add_fp(), smtp_attachment_add_mem(), smtp_attachment_add_path(), smtp_auth(), smtp_close(), smtp_func_test_all_status_code_get(), smtp_getline(), smtp_header_add(), smtp_initiate_handshake(), smtp_mail(), smtp_mail_envelope_header(), smtp_open(), smtp_print_email(), smtp_print_header(), smtp_print_mime_attachment(), smtp_print_mime_header_and_body(), smtp_puts_terminate(), smtp_status_code_clear(), smtp_str_getdelimfd_read_timeout(), smtp_write(), SMTPMail::status_code_set(), test_failure_address_add(), test_failure_attachment_add(), test_failure_auth(), test_failure_header_add(), test_failure_mail(), and test_failure_status_code_set().

                                                        {
   if((unsigned)status_code >= SMTP_STATUS__LAST){
     return smtp_status_code_set(smtp, SMTP_STATUS_PARAM);
   }
   smtp->status_code = status_code;
   return status_code;
 }

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Data Structures

Macros

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ SIZE_MAX

Enumeration Type Documentation

◆ smtp_address_type

◆ smtp_authentication_method

◆ smtp_connection_security

◆ smtp_flag

◆ smtp_result_code

◆ smtp_status_code

◆ str_getdelim_retcode

Function Documentation

◆ smtp_address_add()

◆ smtp_address_clear_all()

◆ smtp_attachment_add_fp()

◆ smtp_attachment_add_mem()

◆ smtp_attachment_add_path()

◆ smtp_attachment_clear_all()

◆ smtp_auth()

◆ smtp_close()

◆ smtp_header_add()

◆ smtp_header_clear_all()

◆ smtp_mail()

◆ smtp_open()

◆ smtp_status_code_clear()

◆ smtp_status_code_errstr()

◆ smtp_status_code_get()

◆ smtp_status_code_set()