X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=transact.c;h=ec8013a516f03d1f66f83bf4af37a65e25ce0708;hb=da989f7b8294e342572ec5f27f1a6f3f2b1fe56f;hp=6de2dfca07dcac32188a705cfd67fa4bfc7a9579;hpb=34f7ed1fc76dbbcd8f2984d4304ec24ead244b43;p=~andy%2Ffetchmail diff --git a/transact.c b/transact.c index 6de2dfca..ec8013a5 100644 --- a/transact.c +++ b/transact.c @@ -1,5 +1,5 @@ -/* - * transact.c -- transaction primitives for the fetchmail driver loop +/** + * \file transact.c -- transaction primitives for the fetchmail driver loop * * Copyright 2001 by Eric S. Raymond * For license terms, see the file COPYING in this directory. @@ -23,6 +23,8 @@ #else #include #endif +#include +#include #ifdef HAVE_NET_SOCKET_H #include @@ -35,27 +37,39 @@ #include "socket.h" #include "fetchmail.h" +/** Macro to clamp the argument so it is >= INT_MIN. */ +#define _FIX_INT_MIN(x) ((x) < INT_MIN ? INT_MIN : (x)) +/** Macro to clamp the argument so it is <= INT_MAX. */ +#define _FIX_INT_MAX(x) ((x) > INT_MAX ? INT_MAX : (x)) +/** Macro to clamp the argument so it is representable as an int. */ +#define CAST_TO_INT(x) ((int)(_FIX_INT_MIN(_FIX_INT_MAX(x)))) +/** Macro to clamp the unsigned argument so it is representable as an int. */ +#define UCAST_TO_INT(x) ((int)(_FIX_INT_MAX(x))) + /* global variables: please reinitialize them explicitly for proper * working in daemon mode */ /* session variables initialized in init_transact() */ -int suppress_tags = FALSE; /* emit tags? */ -char tag[TAGLEN]; -static int tagnum; +int suppress_tags = FALSE; /**< emit tags in the protocol? */ +char tag[TAGLEN]; /**< buffer for the tag */ +static int tagnum; /**< local counter for the tag */ +/** Macro to generate the tag and store it in #tag. */ #define GENSYM (sprintf(tag, "A%04d", ++tagnum % TAGMOD), tag) -static const struct method *protocol; -char shroud[PASSWORDLEN*2+3]; /* string to shroud in debug output */ +static const struct method *protocol; /**< description of the protocol used for the current poll */ +char shroud[PASSWORDLEN*2+3]; /**< string to shroud in debug output */ /* session variables initialized in do_session() */ -int mytimeout; /* value of nonreponse timeout */ +int mytimeout; /**< value of nonreponse timeout */ /* mail variables initialized in readheaders() */ -struct msgblk msgblk; -static int accept_count, reject_count; +struct msgblk msgblk; /**< stores attributes of the currently processed message */ +static int accept_count /** count of accepted recipients */, reject_count /** count of rejected recipients */; /** add given address to xmit_names if it exactly matches a full address * \returns nonzero if matched */ -static int map_address(const char *addr, struct query *ctl, struct idlist **xmit_names) +static int map_address(const char *addr,/**< address to match */ + struct query *ctl, /**< contains list of aliases */ + struct idlist **xmit_names /**< list of recipient names */) { const char *lname; @@ -71,9 +85,9 @@ static int map_address(const char *addr, struct query *ctl, struct idlist **xmit /** add given name to xmit_names if it matches declared localnames */ static void map_name(const char *name, struct query *ctl, struct idlist **xmit_names) -/* name: name to map */ -/* ctl: list of permissible aliases */ -/* xmit_names: list of recipient names parsed out */ +/** \param name name to map */ +/** \param ctl list of permissible aliases */ +/** \param xmit_names list of recipient names parsed out */ { const char *lname; @@ -93,10 +107,10 @@ static void map_name(const char *name, struct query *ctl, struct idlist **xmit_n static void find_server_names(const char *hdr, struct query *ctl, struct idlist **xmit_names) -/* parse names out of a RFC822 header into an ID list */ -/* hdr: RFC822 header in question */ -/* ctl: list of permissible aliases */ -/* xmit_names: list of recipient names parsed out */ +/** parse names out of a RFC822 header into an ID list */ +/** \param hdr RFC822 header in question */ +/** \param ctl list of permissible aliases */ +/** \param xmit_names list of recipient names parsed out */ { if (hdr == (char *)NULL) return; @@ -183,35 +197,37 @@ static void find_server_names(const char *hdr, } } -/* +/** * Return zero on a syntactically invalid address, nz on a valid one. * * This used to be strchr(a, '.'), but it turns out that lines like this * - * Received: from punt-1.mail.demon.net by mailstore for markb@ordern.com + * Received: from punt-1.mail.demon.net by mailstore for markb@example.com * id 938765929:10:27223:2; Fri, 01 Oct 99 08:18:49 GMT * * are not uncommon. So now we just check that the following token is * not itself an email address. */ -#define VALID_ADDRESS(a) !strchr(a, '@') +#define VALID_ADDRESS(a) (!strchr((a), '@')) -static char *parse_received(struct query *ctl, char *bufp) -/* try to extract real address from the Received line */ -/* If a valid Received: line is found, we return the full address in - * a buffer which can be parsed from nxtaddr(). This is to ansure that +/** write \a value into \a rbuf, indexed by \a tp, if there is + * sufficient room left. */ +#define RBUF_WRITE(value) do { if (tp < rbuf+sizeof(rbuf)-1) *tp++=(value); } while(0) + +/** Try to extract real address from the Received line. + * If a valid Received: line is found, we return the full address in + * a buffer which can be parsed from nxtaddr(). This is to ensure that * the local domain part of the address can be passed along in * find_server_names() if it contains one. * Note: We should return a dummy header containing the address * which makes nxtaddr() behave correctly. */ +static char *parse_received(struct query *ctl, char *bufp) { char *base, *ok = (char *)NULL; static char rbuf[HOSTLEN + USERNAMELEN + 4]; struct addrinfo *ai0; -#define RBUF_WRITE(value) if (tp < rbuf+sizeof(rbuf)-1) *tp++=value - /* * Try to extract the real envelope addressee. We look here * specifically for the mailserver's Received line. @@ -357,7 +373,7 @@ static char *parse_received(struct query *ctl, char *bufp) } /* shared by readheaders and readbody */ -static int sizeticker; +static int sizeticker; /**< internal state variable for print_ticker() */ /** Print ticker based on a amount of data transferred of \a bytes. * Increments \a *tickervar by \a bytes, and if it exceeds @@ -376,30 +392,32 @@ static void print_ticker(int *tickervar, int bytes) } } +/** Check if \a s is equal to a LF or CR LF sequence, followed by a NUL + * byte. \todo FIXME merge this with end_of_header? */ #define EMPTYLINE(s) (((s)[0] == '\r' && (s)[1] == '\n' && (s)[2] == '\0') \ || ((s)[0] == '\n' && (s)[1] == '\0')) +/** Check if \a s is an empty line. Accept "\r*\n" as EOH in order to be bulletproof against broken survers */ static int end_of_header (const char *s) -/* accept "\r*\n" as EOH in order to be bulletproof against broken survers */ { while (s[0] == '\r') s++; return (s[0] == '\n' && s[1] == '\0'); } +/** read message headers and ship to SMTP or MDA */ int readheaders(int sock, long fetchlen, long reallen, struct query *ctl, int num, flag *suppress_readbody) -/* read message headers and ship to SMTP or MDA */ -/* sock: to which the server is connected */ -/* fetchlen: length of message according to fetch response */ -/* reallen: length of message according to getsizes */ -/* ctl: query control record */ -/* num: index of message */ -/* suppress_readbody: whether call to readbody() should be supressed */ +/** \param sock to which the server is connected */ +/** \param fetchlen length of message according to fetch response */ +/** \param reallen length of message according to getsizes */ +/** \param ctl query control record */ +/** \param num index of message */ +/** \param suppress_readbody output: whether call to readbody() should be supressed */ { struct addrblk { @@ -592,7 +610,7 @@ eoh: has_nuls = TRUE; if (outlevel > O_SILENT) report(stdout, - GT_("incorrect header line found while scanning headers\n")); + GT_("incorrect header line found - see manpage for bad-header option\n")); if (outlevel >= O_VERBOSE) report (stdout, GT_("line: %s"), line); refuse_mail = 1; @@ -624,7 +642,7 @@ eoh: * our terminating combination \n\0, we move backwards to * make sure that we don't catch some \n\0 stored in the * decoded part of the message */ - for (tcp = line + linelen - 1; tcp > line && (*tcp != 0 || tcp[-1] != '\n'); tcp--); + for (tcp = line + linelen - 1; tcp > line && (*tcp != 0 || tcp[-1] != '\n'); tcp--) { } if (tcp > line) linelen = tcp - line; } @@ -1082,15 +1100,25 @@ process_headers: free(sdps_envto); } else #endif /* SDPS_ENABLE */ - if (env_offs > -1) /* We have the actual envelope addressee */ - find_server_names(msgblk.headers + env_offs, ctl, &msgblk.recipients); + if (env_offs > -1) { /* We have the actual envelope addressee */ + if (outlevel >= O_DEBUG) { + const char *tmps = msgblk.headers + env_offs; + size_t l = strcspn(tmps, "\r\n"); + report(stdout, GT_("Parsing envelope \"%s\" names \"%-.*s\"\n"), ctl->server.envelope, UCAST_TO_INT(l), tmps); + } + find_server_names(msgblk.headers + env_offs, ctl, &msgblk.recipients); + } else if (delivered_to && ctl->server.envelope != STRING_DISABLED && - ctl->server.envelope && !strcasecmp(ctl->server.envelope, "Delivered-To")) - { + ctl->server.envelope && !strcasecmp(ctl->server.envelope, "Delivered-To")) + { + if (outlevel >= O_DEBUG) { + const char *tmps = delivered_to + 2 + strlen(ctl->server.envelope); + size_t l = strcspn(tmps, "\r\n"); + report(stdout, GT_("Parsing envelope \"%s\" names \"%-.*s\"\n"), ctl->server.envelope, UCAST_TO_INT(l), tmps); + } find_server_names(delivered_to, ctl, &msgblk.recipients); xfree(delivered_to); - } - else if (received_for) + } else if (received_for) { /* * We have the Received for addressee. * It has to be a mailserver address, or we @@ -1098,9 +1126,13 @@ process_headers: * We use find_server_names() to let local * hostnames go through. */ + if (outlevel >= O_DEBUG) { + const char *tmps = received_for + 2; + size_t l = strcspn(tmps, "\r\n"); + report(stdout, GT_("Parsing Received names \"%-.*s\"\n"), UCAST_TO_INT(l), tmps); + } find_server_names(received_for, ctl, &msgblk.recipients); - else - { + } else { /* * We haven't extracted the envelope address. * So check all the "Resent-To" header addresses if @@ -1108,6 +1140,8 @@ process_headers: * the "To" addresses. */ register struct addrblk *nextptr; + if (outlevel >= O_DEBUG) + report(stdout, GT_("No envelope recipient found, resorting to header guessing.\n")); if (resent_to_addrchain) { /* delete the "To" chain and substitute it * with the "Resent-To" list @@ -1122,6 +1156,12 @@ process_headers: } /* now look for remaining adresses */ while (to_addrchain) { + if (outlevel >= O_DEBUG) { + const char *tmps = msgblk.headers+to_addrchain->offset; + size_t l = strcspn(tmps, "\r\n"); + report(stdout, GT_("Guessing from header \"%-.*s\".\n"), UCAST_TO_INT(l), tmps); + } + find_server_names(msgblk.headers+to_addrchain->offset, ctl, &msgblk.recipients); nextptr = to_addrchain->next; free(to_addrchain); @@ -1344,11 +1384,11 @@ process_headers: } int readbody(int sock, struct query *ctl, flag forward, int len) -/* read and dispose of a message body presented on sock */ -/* ctl: query control record */ -/* sock: to which the server is connected */ -/* len: length of message */ -/* forward: TRUE to forward */ +/** read and dispose of a message body presented on \a sock */ +/** \param ctl query control record */ +/** \param sock to which the server is connected */ +/** \param forward TRUE to forward */ +/** \param len length of message */ { int linelen; char buf[MSGBUFSIZE+4]; @@ -1395,7 +1435,15 @@ int readbody(int sock, struct query *ctl, flag forward, int len) * so we might end truncating messages prematurely. */ if (!protocol->delimited && linelen > len) { + /* FIXME: HACK ALERT! This \r\n is only here to make sure the + * \n\0 hunt works later on. The \n generated here was not + * part of the original message! + * The real fix will be to use buffer + length strings, + * rather than 0-terminated C strings. */ + inbufp[len++] = '\r'; + inbufp[len++] = '\n'; inbufp[len] = '\0'; + linelen = len; } len -= linelen; @@ -1458,7 +1506,7 @@ int readbody(int sock, struct query *ctl, flag forward, int len) } void init_transact(const struct method *proto) -/* initialize state for the send and receive functions */ +/** initialize state for the send and receive functions */ { suppress_tags = FALSE; tagnum = 0; @@ -1467,8 +1515,8 @@ void init_transact(const struct method *proto) shroud[0] = '\0'; } +/** shroud a password in the given buffer */ static void enshroud(char *buf) -/* shroud a password in the given buffer */ { char *cp; @@ -1485,14 +1533,14 @@ static void enshroud(char *buf) } #if defined(HAVE_STDARG_H) +/** assemble command in printf(3) style and send to the server */ void gen_send(int sock, const char *fmt, ... ) #else void gen_send(sock, fmt, va_alist) -int sock; /* socket to which server is connected */ -const char *fmt; /* printf-style format */ +int sock; /** socket to which server is connected */ +const char *fmt; /** printf-style format */ va_dcl #endif -/* assemble command in printf(3) style and send to the server */ { char buf [MSGBUFSIZE+1]; va_list ap; @@ -1523,9 +1571,10 @@ va_dcl /** get one line of input from the server */ int gen_recv(int sock /** socket to which server is connected */, - char *buf /* buffer to receive input */, - int size /* length of buffer */) + char *buf /** buffer to receive input */, + int size /** length of buffer */) { + size_t n; int oldphase = phase; /* we don't have to be re-entrant */ phase = SERVER_WAIT; @@ -1545,10 +1594,11 @@ int gen_recv(int sock /** socket to which server is connected */, else { set_timeout(0); - if (buf[strlen(buf)-1] == '\n') - buf[strlen(buf)-1] = '\0'; - if (buf[strlen(buf)-1] == '\r') - buf[strlen(buf)-1] = '\0'; + n = strlen(buf); + if (n > 0 && buf[n-1] == '\n') + buf[--n] = '\0'; + if (n > 0 && buf[n-1] == '\r') + buf[--n] = '\0'; if (outlevel >= O_MONITOR) report(stdout, "%s< %s\n", protocol->name, buf); phase = oldphase; @@ -1556,15 +1606,141 @@ int gen_recv(int sock /** socket to which server is connected */, } } +/** \addtogroup gen_recv_split + * @{ + * gen_recv_split() splits the response from a server which is too + * long to fit into the buffer into multiple lines. If the prefix is + * set as "MY FEATURES" and the response from the server is too long + * to fit in the buffer, as in: + * + * "MY FEATURES ABC DEF GHI JKLMNOPQRS TU VWX YZ" + * + * Repeated calls to gen_recv_split() may return: + * + * "MY FEATURES ABC DEF GHI" + * "MY FEATURES JKLMNOPQRS" + * "MY FEATURES TU VWX YZ" + * + * A response not beginning with the prefix "MY FEATURES" will not be + * split. + * + * To use: + * - Declare a variable of type struct RecvSplit + * - Call gen_recv_split_init() once + * - Call gen_recv_split() in a loop, preferably with the same buffer + * size as the "buf" array in struct RecvSplit + */ + +static void overrun(const char *f, size_t l) __attribute__((noreturn)); + +/** Internal error report function. If this happens, the calling site + * needs to be adjusted to set a shorter prefix, or the prefix capacity + * needs to be raised in struct RecvSplit. */ +static void overrun(const char *f, size_t l) +{ + report(stderr, GT_("Buffer too small. This is a bug in the caller of %s:%lu.\n"), f, (unsigned long)l); + abort(); +} + +/** Initialize \a rs for later use by gen_recv_split. */ +void gen_recv_split_init (const char *prefix /** prefix to match/repeat */, + struct RecvSplit *rs /** structure to be initialized */) +{ + if (strlcpy(rs->prefix, prefix, sizeof(rs->prefix)) > sizeof(rs->prefix)) + overrun(__FILE__, __LINE__); + rs->cached = 0; + rs->buf[0] = '\0'; +} + +/** Function to split replies at blanks, and duplicate prefix. + * gen_recv_split_init() must be called before this can be used. */ +int gen_recv_split(int sock /** socket to which server is connected */, + char *buf /** buffer to receive input */, + int size /** length of buffer, must be the same for all calls */, + struct RecvSplit *rs /** cached information across calls */) +{ + size_t n = 0; + int foundnewline = 0; + char *p; + int oldphase = phase; /* we don't have to be re-entrant */ + + assert(size > 0); + + /* if this is not our first call, prepare the buffer */ + if (rs->cached) + { + /* + * if this condition is not met, we lose data + * because the cached data does not fit into the buffer. + * this cannot happen if size is the same throughout all calls. + */ + assert(strlen(rs->prefix) + strlen(rs->buf) + 1 <= (size_t)size); + + if ((strlcpy(buf, rs->prefix, size) >= (size_t)size) + || (strlcat(buf, rs->buf, size) >= (size_t)size)) { + overrun(__FILE__, __LINE__); + } + + n = strlen(buf); + /* clear the cache for the next call */ + rs->cached = 0; + rs->buf[0] = '\0'; + } + + if ((size_t)size > n) { + int rr; + + phase = SERVER_WAIT; + set_timeout(mytimeout); + rr = SockRead(sock, buf + n, size - n); + set_timeout(0); + phase = oldphase; + if (rr == -1) + return PS_SOCKET; + } + + n = strlen(buf); + if (n > 0 && buf[n-1] == '\n') + { + buf[--n] = '\0'; + foundnewline = 1; + } + if (n > 0 && buf[n-1] == '\r') + buf[--n] = '\0'; + + if (foundnewline /* we have found a complete line */ + || strncasecmp(buf, rs->prefix, strlen(rs->prefix)) /* mismatch in prefix */ + || !(p = strrchr(buf, ' ')) /* no space found in response */ + || p < buf + strlen(rs->prefix)) /* space is at the wrong location */ + { + if (outlevel >= O_MONITOR) + report(stdout, "%s< %s\n", protocol->name, buf); + return(PS_SUCCESS); + } + + /* we are ready to cache some information now. */ + rs->cached = 1; + if (strlcpy(rs->buf, p, sizeof(rs->buf)) >= sizeof(rs->buf)) { + overrun(__FILE__, __LINE__); + } + *p = '\0'; /* chop off what we've cached */ + if (outlevel >= O_MONITOR) + report(stdout, "%s< %s\n", protocol->name, buf); + if (outlevel >= O_DEBUG) + report(stdout, "%s< %s%s...\n", protocol->name, rs->prefix, rs->buf); + return(PS_SUCCESS); +} +/** @} */ + #if defined(HAVE_STDARG_H) int gen_transact(int sock, const char *fmt, ... ) #else int gen_transact(int sock, fmt, va_alist) -int sock; /* socket to which server is connected */ -const char *fmt; /* printf-style format */ +int sock; /** socket to which server is connected */ +const char *fmt; /** printf-style format */ va_dcl #endif -/* assemble command in printf(3) style, send to server, accept a response */ +/** assemble command in printf(3) style, send to server, fetch a response */ { int ok; char buf [MSGBUFSIZE+1];