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Diffstat (limited to 'src/lookups/mysql.c')
| -rw-r--r-- | src/lookups/mysql.c | 503 |
1 files changed, 503 insertions, 0 deletions
diff --git a/src/lookups/mysql.c b/src/lookups/mysql.c new file mode 100644 index 0000000..78b8c2b --- /dev/null +++ b/src/lookups/mysql.c @@ -0,0 +1,503 @@ +/************************************************* +* Exim - an Internet mail transport agent * +*************************************************/ + +/* Copyright (c) The Exim Maintainers 2020 - 2022 */ +/* Copyright (c) University of Cambridge 1995 - 2018 */ +/* See the file NOTICE for conditions of use and distribution. */ + +/* Thanks to Paul Kelly for contributing the original code for these +functions. */ + + +#include "../exim.h" +#include "lf_functions.h" + +#include <mysql.h> /* The system header */ + +/* We define symbols for *_VERSION_ID (numeric), *_VERSION_STR (char*) +and *_BASE_STR (char*). It's a bit of guesswork. Especially for mariadb +with versions before 10.2, as they do not define there there specific symbols. +*/ + +/* Newer (>= 10.2) MariaDB */ +#if defined MARIADB_VERSION_ID +#define EXIM_MxSQL_VERSION_ID MARIADB_VERSION_ID + +/* MySQL defines MYSQL_VERSION_ID, and MariaDB does so */ +/* https://dev.mysql.com/doc/refman/5.7/en/c-api-server-client-versions.html */ +#elif defined LIBMYSQL_VERSION_ID +#define EXIM_MxSQL_VERSION_ID LIBMYSQL_VERSION_ID +#elif defined MYSQL_VERSION_ID +#define EXIM_MxSQL_VERSION_ID MYSQL_VERSION_ID + +#else +#define EXIM_MYSQL_VERSION_ID 0 +#endif + +/* Newer (>= 10.2) MariaDB */ +#ifdef MARIADB_CLIENT_VERSION_STR +#define EXIM_MxSQL_VERSION_STR MARIADB_CLIENT_VERSION_STR + +/* Mysql uses MYSQL_SERVER_VERSION */ +#elif defined LIBMYSQL_VERSION +#define EXIM_MxSQL_VERSION_STR LIBMYSQL_VERSION +#elif defined MYSQL_SERVER_VERSION +#define EXIM_MxSQL_VERSION_STR MYSQL_SERVER_VERSION + +#else +#define EXIM_MxSQL_VERSION_STR "unknown" +#endif + +#if defined MARIADB_BASE_VERSION +#define EXIM_MxSQL_BASE_STR MARIADB_BASE_VERSION + +#elif defined MARIADB_PACKAGE_VERSION +#define EXIM_MxSQL_BASE_STR "mariadb" + +#elif defined MYSQL_BASE_VERSION +#define EXIM_MxSQL_BASE_STR MYSQL_BASE_VERSION + +#else +#define EXIM_MxSQL_BASE_STR "n.A." +#endif + + +/* Structure and anchor for caching connections. */ + +typedef struct mysql_connection { + struct mysql_connection *next; + uschar *server; + MYSQL *handle; +} mysql_connection; + +static mysql_connection *mysql_connections = NULL; + + + +/************************************************* +* Open entry point * +*************************************************/ + +/* See local README for interface description. */ + +static void * +mysql_open(const uschar * filename, uschar ** errmsg) +{ +return (void *)(1); /* Just return something non-null */ +} + + + +/************************************************* +* Tidy entry point * +*************************************************/ + +/* See local README for interface description. */ + +static void +mysql_tidy(void) +{ +mysql_connection *cn; +while ((cn = mysql_connections) != NULL) + { + mysql_connections = cn->next; + DEBUG(D_lookup) debug_printf_indent("close MYSQL connection: %s\n", cn->server); + mysql_close(cn->handle); + } +} + + + +/************************************************* +* Internal search function * +*************************************************/ + +/* This function is called from the find entry point to do the search for a +single server. + +Arguments: + query the query string + server the server string + resultptr where to store the result + errmsg where to point an error message + defer_break TRUE if no more servers are to be tried after DEFER + do_cache set zero if data is changed + opts options + +The server string is of the form "host/dbname/user/password". The host can be +host:port. This string is in a nextinlist temporary buffer, so can be +overwritten. + +Returns: OK, FAIL, or DEFER +*/ + +static int +perform_mysql_search(const uschar *query, uschar *server, uschar **resultptr, + uschar **errmsg, BOOL *defer_break, uint *do_cache, const uschar * opts) +{ +MYSQL *mysql_handle = NULL; /* Keep compilers happy */ +MYSQL_RES *mysql_result = NULL; +MYSQL_ROW mysql_row_data; +MYSQL_FIELD *fields; + +int i; +int yield = DEFER; +unsigned int num_fields; +gstring * result = NULL; +mysql_connection *cn; +uschar *server_copy = NULL; +uschar *sdata[4]; + +/* Disaggregate the parameters from the server argument. The order is host, +database, user, password. We can write to the string, since it is in a +nextinlist temporary buffer. The copy of the string that is used for caching +has the password removed. This copy is also used for debugging output. */ + +for (int i = 3; i > 0; i--) + { + uschar *pp = Ustrrchr(server, '/'); + if (!pp) + { + *errmsg = string_sprintf("incomplete MySQL server data: %s", + (i == 3)? server : server_copy); + *defer_break = TRUE; + return DEFER; + } + *pp++ = 0; + sdata[i] = pp; + if (i == 3) server_copy = string_copy(server); /* sans password */ + } +sdata[0] = server; /* What's left at the start */ + +/* See if we have a cached connection to the server */ + +for (cn = mysql_connections; cn; cn = cn->next) + if (Ustrcmp(cn->server, server_copy) == 0) + { mysql_handle = cn->handle; break; } + +/* If no cached connection, we must set one up. Mysql allows for a host name +and port to be specified. It also allows the name of a Unix socket to be used. +Unfortunately, this contains slashes, but its use is expected to be rare, so +the rather cumbersome syntax shouldn't inconvenience too many people. We use +this: host:port(socket)[group] where all the parts are optional. +The "group" parameter specifies an option group from a MySQL option file. */ + +if (!cn) + { + uschar *p; + uschar *socket = NULL; + int port = 0; + uschar *group = US"exim"; + + if ((p = Ustrchr(sdata[0], '['))) + { + *p++ = 0; + group = p; + while (*p && *p != ']') p++; + *p = 0; + } + + if ((p = Ustrchr(sdata[0], '('))) + { + *p++ = 0; + socket = p; + while (*p && *p != ')') p++; + *p = 0; + } + + if ((p = Ustrchr(sdata[0], ':'))) + { + *p++ = 0; + port = Uatoi(p); + } + + if (Ustrchr(sdata[0], '/')) + { + *errmsg = string_sprintf("unexpected slash in MySQL server hostname: %s", + sdata[0]); + *defer_break = TRUE; + return DEFER; + } + + /* If the database is the empty string, set it NULL - the query must then + define it. */ + + if (sdata[1][0] == 0) sdata[1] = NULL; + + DEBUG(D_lookup) + debug_printf_indent("MYSQL new connection: host=%s port=%d socket=%s " + "database=%s user=%s\n", sdata[0], port, socket, sdata[1], sdata[2]); + + /* Get store for a new handle, initialize it, and connect to the server */ + + mysql_handle = store_get(sizeof(MYSQL), GET_UNTAINTED); + mysql_init(mysql_handle); + mysql_options(mysql_handle, MYSQL_READ_DEFAULT_GROUP, CS group); + if (mysql_real_connect(mysql_handle, + /* host user passwd database */ + CS sdata[0], CS sdata[2], CS sdata[3], CS sdata[1], + port, CS socket, CLIENT_MULTI_RESULTS) == NULL) + { + *errmsg = string_sprintf("MYSQL connection failed: %s", + mysql_error(mysql_handle)); + *defer_break = FALSE; + goto MYSQL_EXIT; + } + + /* Add the connection to the cache */ + + cn = store_get(sizeof(mysql_connection), GET_UNTAINTED); + cn->server = server_copy; + cn->handle = mysql_handle; + cn->next = mysql_connections; + mysql_connections = cn; + } + +/* Else use a previously cached connection */ + +else + { + DEBUG(D_lookup) + debug_printf_indent("MYSQL using cached connection for %s\n", server_copy); + } + +/* Run the query */ + +if (mysql_query(mysql_handle, CS query) != 0) + { + *errmsg = string_sprintf("MYSQL: query failed: %s\n", + mysql_error(mysql_handle)); + *defer_break = FALSE; + goto MYSQL_EXIT; + } + +/* Pick up the result. If the query was not of the type that returns data, +namely INSERT, UPDATE, or DELETE, an error occurs here. However, this situation +can be detected by calling mysql_field_count(). If its result is zero, no data +was expected (this is all explained clearly in the MySQL manual). In this case, +we return the number of rows affected by the command. In this event, we do NOT +want to cache the result; also the whole cache for the handle must be cleaned +up. Setting do_cache zero requests this. */ + +if (!(mysql_result = mysql_use_result(mysql_handle))) + { + if (mysql_field_count(mysql_handle) == 0) + { + DEBUG(D_lookup) debug_printf_indent("MYSQL: query was not one that returns data\n"); + result = string_cat(result, + string_sprintf("%lld", mysql_affected_rows(mysql_handle))); + *do_cache = 0; + goto MYSQL_EXIT; + } + *errmsg = string_sprintf("MYSQL: lookup result failed: %s\n", + mysql_error(mysql_handle)); + *defer_break = FALSE; + goto MYSQL_EXIT; + } + +/* Find the number of fields returned. If this is one, we don't add field +names to the data. Otherwise we do. */ + +num_fields = mysql_num_fields(mysql_result); + +/* Get the fields and construct the result string. If there is more than one +row, we insert '\n' between them. */ + +fields = mysql_fetch_fields(mysql_result); + +while ((mysql_row_data = mysql_fetch_row(mysql_result))) + { + unsigned long * lengths = mysql_fetch_lengths(mysql_result); + + if (result) + result = string_catn(result, US"\n", 1); + + if (num_fields != 1) + for (int i = 0; i < num_fields; i++) + result = lf_quote(US fields[i].name, US mysql_row_data[i], lengths[i], + result); + + else if (mysql_row_data[0] != NULL) /* NULL value yields nothing */ + result = lengths[0] == 0 && !result + ? string_get(1) /* for 0-len string result ensure non-null gstring */ + : string_catn(result, US mysql_row_data[0], lengths[0]); + } + +/* more results? -1 = no, >0 = error, 0 = yes (keep looping) + This is needed because of the CLIENT_MULTI_RESULTS on mysql_real_connect(), + we don't expect any more results. */ + +while((i = mysql_next_result(mysql_handle)) >= 0) + if(i != 0) + { + *errmsg = string_sprintf( + "MYSQL: lookup result error when checking for more results: %s\n", + mysql_error(mysql_handle)); + goto MYSQL_EXIT; + } + else /* just ignore more results */ + DEBUG(D_lookup) debug_printf_indent("MYSQL: got unexpected more results\n"); + +/* If result is NULL then no data has been found and so we return FAIL. +Otherwise, we must terminate the string which has been built; string_cat() +always leaves enough room for a terminating zero. */ + +if (!result) + { + yield = FAIL; + *errmsg = US"MYSQL: no data found"; + } + +/* Get here by goto from various error checks and from the case where no data +was read (e.g. an update query). */ + +MYSQL_EXIT: + +/* Free mysal store for any result that was got; don't close the connection, as +it is cached. */ + +if (mysql_result) mysql_free_result(mysql_result); + +/* Non-NULL result indicates a successful result */ + +if (result) + { + *resultptr = string_from_gstring(result); + gstring_release_unused(result); + return OK; + } +else + { + DEBUG(D_lookup) debug_printf_indent("%s\n", *errmsg); + return yield; /* FAIL or DEFER */ + } +} + + + + +/************************************************* +* Find entry point * +*************************************************/ + +/* See local README for interface description. The handle and filename +arguments are not used. The code to loop through a list of servers while the +query is deferred with a retryable error is now in a separate function that is +shared with other SQL lookups. */ + +static int +mysql_find(void * handle, const uschar * filename, const uschar * query, + int length, uschar ** result, uschar ** errmsg, uint * do_cache, + const uschar * opts) +{ +return lf_sqlperform(US"MySQL", US"mysql_servers", mysql_servers, query, + result, errmsg, do_cache, opts, perform_mysql_search); +} + + + +/************************************************* +* Quote entry point * +*************************************************/ + +/* The only characters that need to be quoted (with backslash) are newline, +tab, carriage return, backspace, backslash itself, and the quote characters. +Percent, and underscore and not escaped. They are only special in contexts +where they can be wild cards, and this isn't usually the case for data inserted +from messages, since that isn't likely to be treated as a pattern of any kind. +Sadly, MySQL doesn't seem to behave like other programs. If you use something +like "where id="ab\%cd" it does not treat the string as "ab%cd". So you really +can't quote "on spec". + +Arguments: + s the string to be quoted + opt additional option text or NULL if none + idx lookup type index + +Returns: the processed string or NULL for a bad option +*/ + +static uschar * +mysql_quote(uschar * s, uschar * opt, unsigned idx) +{ +int c, count = 0; +uschar * t = s, * quoted; + +if (opt) return NULL; /* No options recognized */ + +while ((c = *t++)) + if (Ustrchr("\n\t\r\b\'\"\\", c) != NULL) count++; + +/* Old code: if (count == 0) return s; +Now always allocate and copy, to track the quoted status. */ + +t = quoted = store_get_quoted(Ustrlen(s) + count + 1, s, idx); + +while ((c = *s++)) + { + if (Ustrchr("\n\t\r\b\'\"\\", c) != NULL) + { + *t++ = '\\'; + switch(c) + { + case '\n': *t++ = 'n'; break; + case '\t': *t++ = 't'; break; + case '\r': *t++ = 'r'; break; + case '\b': *t++ = 'b'; break; + default: *t++ = c; break; + } + } + else *t++ = c; + } + +*t = 0; +return quoted; +} + + +/************************************************* +* Version reporting entry point * +*************************************************/ + +/* See local README for interface description. */ + +#include "../version.h" + +gstring * +mysql_version_report(gstring * g) +{ +g = string_fmt_append(g, + "Library version: MySQL: Compile: %lu %s [%s]\n" + " Runtime: %lu %s\n", + (long)EXIM_MxSQL_VERSION_ID, EXIM_MxSQL_VERSION_STR, EXIM_MxSQL_BASE_STR, + mysql_get_client_version(), mysql_get_client_info()); +#ifdef DYNLOOKUP +g = string_fmt_append(g, + " Exim version %s\n", EXIM_VERSION_STR); +#endif +return g; +} + +/* These are the lookup_info blocks for this driver */ + +static lookup_info mysql_lookup_info = { + .name = US"mysql", /* lookup name */ + .type = lookup_querystyle, /* query-style lookup */ + .open = mysql_open, /* open function */ + .check = NULL, /* no check function */ + .find = mysql_find, /* find function */ + .close = NULL, /* no close function */ + .tidy = mysql_tidy, /* tidy function */ + .quote = mysql_quote, /* quoting function */ + .version_report = mysql_version_report /* version reporting */ +}; + +#ifdef DYNLOOKUP +#define mysql_lookup_module_info _lookup_module_info +#endif + +static lookup_info *_lookup_list[] = { &mysql_lookup_info }; +lookup_module_info mysql_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 }; + +/* End of lookups/mysql.c */ |