src/src/local_scan.h

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2020 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 /* This file is the header that is the only Exim header to be included in the
   9 source for the local_scan.c() function. It contains definitions that are made
  10 available for use in that function, and which are documented.  That source
  11 should first #define LOCAL_SCAN
  12
  13 Not every definition that becomes available to the compiler by the inclusion
  14 of this file is part of the local_scan API.  The "Adding a local scan function
  15 to Exim" chapter in the documentation is definitive.
  16
  17 This API is also used for functions called by the ${dlfunc expansion item.
  18 Source for those should first #define DLFUNC_IMPL and then include this file.
  19 Coders of dlfunc routines should read the notes on tainting at the start of
  20 store.c
  21 */
  22
  23
  24 /* Some basic types that make some things easier, the Exim configuration
  25 settings, and the store functions. */
  26
  27 #include <stdarg.h>
  28 #include <sys/types.h>
  29 #include "config.h"
  30 #include "mytypes.h"
  31 #include "store.h"
  32
  33
  34 /* Some people (Marc Merlin et al) are maintaining a patch that allows for
  35 dynamic local_scan() libraries. This code is not yet in Exim proper, but it
  36 helps the maintainers if we keep their ABI version numbers here. This may
  37 mutate into more general support later. The major number is increased when the
  38 ABI is changed in a non backward compatible way. The minor number is increased
  39 each time a new feature is added (in a way that doesn't break backward
  40 compatibility). */
  41
  42 #define LOCAL_SCAN_ABI_VERSION_MAJOR 4
  43 #define LOCAL_SCAN_ABI_VERSION_MINOR 1
  44 #define LOCAL_SCAN_ABI_VERSION \
  45   LOCAL_SCAN_ABI_VERSION_MAJOR.LOCAL_SCAN_ABI_VERSION_MINOR
  46
  47
  48
  49 /* The function and its return codes. */
  50
  51 extern int local_scan(int, uschar **);
  52
  53 enum {
  54   LOCAL_SCAN_ACCEPT,              /* Accept */
  55   LOCAL_SCAN_ACCEPT_FREEZE,       /* Accept, but freeze */
  56   LOCAL_SCAN_ACCEPT_QUEUE,        /* Accept, but no immediate delivery */
  57   LOCAL_SCAN_REJECT,              /* Permanent rejection */
  58   LOCAL_SCAN_REJECT_NOLOGHDR,     /* Permanent rejection, no log header */
  59   LOCAL_SCAN_TEMPREJECT,          /* Temporary rejection */
  60   LOCAL_SCAN_TEMPREJECT_NOLOGHDR  /* Temporary rejection, no log header */
  61 };
  62
  63
  64 /* Functions called by ${dlfunc{file}{func}{arg}...} return one of the five
  65 status codes defined immediately below. The function's first argument is either
  66 the result of expansion, or the error message in case of failure. The second
  67 and third arguments are standard argument count and vector, comprising the
  68 {arg} values specified in the expansion item. */
  69
  70 typedef int exim_dlfunc_t(uschar **yield, int argc, uschar *argv[]);
  71
  72
  73 /* Return codes from the support functions lss_match_xxx(). These are also the
  74 codes that dynamically-loaded ${dlfunc functions must return. */
  75
  76 #define  OK            0          /* Successful match */
  77 #define  DEFER         1          /* Defer - some problem */
  78 #define  FAIL          2          /* Matching failed */
  79 #define  ERROR         3          /* Internal or config error */
  80
  81 /* Extra return code for ${dlfunc functions */
  82
  83 #define  FAIL_FORCED   4          /* "Forced" failure */
  84
  85
  86 /* Available logging destinations */
  87
  88 #define LOG_MAIN        1    /* Write to the main log */
  89 #define LOG_PANIC       2    /* Write to the panic log */
  90 #define LOG_REJECT     16    /* Write to the reject log, with headers */
  91
  92
  93 /* Accessible debugging bits */
  94
  95 #define D_v                          0x00000001
  96 #define D_local_scan                 0x00000002
  97
  98
  99 /* Option types that can be used for local_scan_options. The boolean ones
 100 MUST be last so that they are contiguous with the internal boolean specials. */
 101
 102 enum { opt_stringptr, opt_int, opt_octint, opt_mkint, opt_Kint, opt_fixed,
 103   opt_time, opt_bool };
 104
 105
 106 /* The length of message identification strings. This is the id used internally
 107 by exim. The external version for use in Received: strings has a leading 'E'
 108 added to ensure it starts with a letter. */
 109
 110 #define MESSAGE_ID_LENGTH 16
 111
 112 /* The offset to the start of the data in the data file - this allows for
 113 the name of the data file to be present in the first line. */
 114
 115 #define SPOOL_DATA_START_OFFSET (MESSAGE_ID_LENGTH+3)
 116
 117 /* Structure definitions that are documented as visible in the function. */
 118
 119 typedef struct header_line {
 120   struct header_line *next;
 121   int    type;
 122   int    slen;
 123   uschar *text;
 124 } header_line;
 125
 126 /* Entries in lists options are in this form. */
 127
 128 typedef struct {
 129   const char *  name; /* should have been uschar but too late now */
 130   int           type;
 131   union {
 132     void *      value;
 133     long        offset;
 134     void (*     fn)();
 135   } v;
 136 } optionlist;
 137 #define OPT_OFF(s, field) {.offset = offsetof(s, field)}
 138
 139 /* Structure for holding information about an envelope address. The errors_to
 140 field is always NULL except for one_time aliases that had errors_to on the
 141 routers that generated them. */
 142
 143 typedef struct recipient_item {
 144   uschar *address;              /* the recipient address */
 145   int     pno;                  /* parent number for "one_time" alias, or -1 */
 146   uschar *errors_to;            /* the errors_to address or NULL */
 147   uschar *orcpt;                /* DSN orcpt */
 148   int     dsn_flags;            /* DSN flags */
 149 #ifdef EXPERIMENTAL_BRIGHTMAIL
 150   uschar *bmi_optin;
 151 #endif
 152 } recipient_item;
 153
 154
 155 /* Global variables that are documented as visible in the function. */
 156
 157 extern unsigned int debug_selector;    /* Debugging bits */
 158
 159 extern int     body_linecount;         /* Line count in body */
 160 extern int     body_zerocount;         /* Binary zero count in body */
 161 extern uschar *expand_string_message;  /* Error info for failing expansion */
 162 extern uschar *headers_charset;        /* Charset for RFC 2047 decoding */
 163 extern header_line *header_last;       /* Final header */
 164 extern header_line *header_list;       /* First header */
 165 extern BOOL    host_checking;          /* Set when checking a host */
 166 extern uschar *interface_address;      /* Interface for incoming call */
 167 extern int     interface_port;         /* Port number for incoming call */
 168 extern uschar *message_id;             /* Internal id of message being handled */
 169 extern uschar *received_protocol;      /* Name of incoming protocol */
 170 extern int     recipients_count;       /* Number of recipients */
 171 extern recipient_item *recipients_list;/* List of recipient addresses */
 172 extern unsigned char *sender_address;  /* Sender address */
 173 extern uschar *sender_host_address;    /* IP address of sender, as chars */
 174 extern uschar *sender_host_authenticated; /* Name of authentication mechanism */
 175 extern uschar *sender_host_name;       /* Host name from lookup */
 176 extern int     sender_host_port;       /* Port number of sender */
 177 extern BOOL    smtp_batched_input;     /* TRUE if SMTP batch (no interaction) */
 178 extern BOOL    smtp_input;             /* TRUE if input is via SMTP */
 179
 180
 181 /* Functions that are documented as visible in local_scan(). */
 182
 183 extern int     child_close(pid_t, int);
 184 extern void    debug_printf(const char *, ...) PRINTF_FUNCTION(1,2);
 185 extern uschar *expand_string(uschar *);
 186 extern void    header_add(int, const char *, ...);
 187 extern void    header_add_at_position(BOOL, uschar *, BOOL, int, const char *, ...);
 188 extern void    header_remove(int, const uschar *);
 189 extern BOOL    header_testname(header_line *, const uschar *, int, BOOL);
 190 extern BOOL    header_testname_incomplete(header_line *, const uschar *, int, BOOL);
 191 extern void    log_write(unsigned int, int, const char *format, ...) PRINTF_FUNCTION(3,4);
 192 extern int     lss_b64decode(uschar *, uschar **);
 193 extern uschar *lss_b64encode(uschar *, int);
 194 extern int     lss_match_domain(uschar *, uschar *);
 195 extern int     lss_match_local_part(uschar *, uschar *, BOOL);
 196 extern int     lss_match_address(uschar *, uschar *, BOOL);
 197 extern int     lss_match_host(uschar *, uschar *, uschar *);
 198 extern void    receive_add_recipient(uschar *, int);
 199 extern BOOL    receive_remove_recipient(uschar *);
 200 extern uschar *rfc2047_decode(uschar *, BOOL, uschar *, int, int *, uschar **);
 201 extern int     smtp_fflush(void);
 202 extern void    smtp_printf(const char *, BOOL, ...) PRINTF_FUNCTION(1,3);
 203 extern void    smtp_vprintf(const char *, BOOL, va_list);
 204
 205 #define string_sprintf(fmt, ...) \
 206         string_sprintf_trc(fmt, US __FUNCTION__, __LINE__, __VA_ARGS__)
 207 extern uschar *string_sprintf_trc(const char *, const uschar *, unsigned, ...) ALMOST_PRINTF(1,4);
 208
 209 #define store_get(size, tainted) \
 210         store_get_3(size, tainted, __FUNCTION__, __LINE__)
 211 extern void   *store_get_3(int, BOOL, const char *, int)        ALLOC ALLOC_SIZE(1) WARN_UNUSED_RESULT;
 212 #define store_get_perm(size, tainted) \
 213         store_get_perm_3(size, tainted, __FUNCTION__, __LINE__)
 214 extern void   *store_get_perm_3(int, BOOL, const char *, int)   ALLOC ALLOC_SIZE(1) WARN_UNUSED_RESULT;
 215
 216
 217 #if defined(LOCAL_SCAN) || defined(DLFUNC_IMPL)
 218 /* When compiling a local_scan() file we want to rename a published API, so that
 219 we can use an inlined implementation in the compiles of the main Exim files,
 220 with the original name. */
 221
 222 # define string_copy(s) string_copy_function(s)
 223 # define string_copyn(s, n) string_copyn_function((s), (n))
 224 # define string_copy_taint(s, t) string_copy_taint_function((s), (t))
 225 # define child_open_exim(p)        child_open_exim_function((p), US"from local_scan")
 226 # define child_open_exim2(p, s, a) child_open_exim2_function((p), (s), (a), US"from local_scan")
 227 # define child_open(a,e,u,i,o,l) child_open_function((a),(e),(u),(i),(o),(l),US"from local_scan")
 228
 229 extern uschar * string_copy_function(const uschar *);
 230 extern uschar * string_copyn_function(const uschar *, int n);
 231 extern uschar * string_copy_taint_function(const uschar *, BOOL tainted);
 232 extern pid_t    child_open_exim_function(int *, const uschar *);
 233 extern pid_t    child_open_exim2_function(int *, uschar *, uschar *, const uschar *);
 234 extern pid_t    child_open_function(uschar **, uschar **, int, int *, int *, BOOL, const uschar *);
 235 #endif
 236
 237 /* End of local_scan.h */