diff options
| -rw-r--r-- | src/proxsmtpd.c | 506 |
1 files changed, 250 insertions, 256 deletions
diff --git a/src/proxsmtpd.c b/src/proxsmtpd.c index 00c11e7..348aadd 100644 --- a/src/proxsmtpd.c +++ b/src/proxsmtpd.c @@ -75,14 +75,19 @@ pxstate_t; */ #define REJECTED "Content Rejected" + #define DEFAULT_CONFIG CONF_PREFIX "/proxsmtpd.conf" +#define DEFAULT_TIMEOUT 30 #define CFG_FILTERCMD "FilterCommand" -#define CFG_PIPECMD "PipeData" +#define CFG_FILTERTYPE "FilterType" #define CFG_DIRECTORY "TempDirectory" #define CFG_DEBUGFILES "DebugFiles" #define CFG_CMDTIMEOUT "FilterTimeout" +#define TYPE_PIPE "pipe" +#define TYPE_FILE "file" + /* Poll time for waiting operations in milli seconds */ #define POLL_TIME 20 @@ -130,6 +135,7 @@ int main(int argc, char* argv[]) memset(&g_pxstate, 0, sizeof(g_pxstate)); g_pxstate.directory = _PATH_TMP; g_pxstate.pipe_cmd = 1; + g_pxstate.timeout.tv_sec = DEFAULT_TIMEOUT; sp_init("proxsmtpd"); @@ -257,10 +263,14 @@ int cb_parse_option(const char* name, const char* value) return 1; } - else if(strcasecmp(CFG_PIPECMD, name) == 0) + else if(strcasecmp(CFG_FILTERTYPE, name) == 0) { - if((g_pxstate.pipe_cmd = strtob(value)) == -1) - errx(2, "invalid value for " CFG_PIPECMD); + if(strcasecmp(value, TYPE_PIPE) == 0) + g_pxstate.pipe_cmd = 1; + else if(strcasecmp(value, TYPE_FILE) == 0) + g_pxstate.pipe_cmd = 0; + else + errx(2, "invalid value for " CFG_FILTERTYPE " (must specify 'pipe' or 'file')"); return 1; } @@ -284,27 +294,27 @@ void cb_del_context(spctx_t* ctx) * IMPLEMENTATION */ -static int process_file_command(spctx_t* sp) +static pid_t fork_filter(spctx_t* sp, int* infd, int* outfd, int* errfd) { pid_t pid; - int ret = 0, status, r; + int ret = 0; + int r = 0; - /* For reading data from the process */ + /* Pipes for input, output, err */ + int pipe_i[2]; + int pipe_o[2]; int pipe_e[2]; - fd_set rmask; - char obuf[1024]; - char ebuf[256]; - ASSERT(g_pxstate.command); - - memset(ebuf, 0, sizeof(ebuf)); + memset(pipe_i, ~0, sizeof(pipe_i)); + memset(pipe_o, ~0, sizeof(pipe_o)); memset(pipe_e, ~0, sizeof(pipe_e)); - if(sp_cache_data(sp) == -1) - RETURN(-1); /* message already printed */ + ASSERT(g_pxstate.command); - /* Create the pipe we need */ - if(pipe(pipe_e) == -1) + /* Create the pipes we need */ + if((infd && pipe(pipe_i) == -1) || + (outfd && pipe(pipe_o) == -1) || + (errfd && pipe(pipe_e) == -1)) { sp_message(sp, LOG_ERR, "couldn't create pipe for filter command"); RETURN(-1); @@ -320,14 +330,28 @@ static int process_file_command(spctx_t* sp) /* The child process */ case 0: - /* Close our unused ends of the pipes */ - close(pipe_e[READ_END]); + if(r >= 0 && infd) + { + close(pipe_i[WRITE_END]); + r = dup2(pipe_i[READ_END], STDIN); + } + + if(r >= 0 && outfd) + { + close(pipe_o[READ_END]); + r = dup2(pipe_o[WRITE_END], STDOUT); + } + + if(r >= 0 && errfd) + { + close(pipe_e[READ_END]); + r = dup2(pipe_e[WRITE_END], STDERR); + } - /* Fixup our ends of the pipe */ - if(dup2(pipe_e[WRITE_END], STDERR) == -1) + if(r < 0) { - sp_message(sp, LOG_ERR, "couldn't dup descriptor for filter command"); - exit(1); + sp_message(sp, LOG_ERR, "couldn't dup descriptors for filter command"); + _exit(1); } /* All the necessary environment vars */ @@ -345,20 +369,76 @@ static int process_file_command(spctx_t* sp) /* The parent process */ sp_messagex(sp, LOG_DEBUG, "executed filter command: %s (pid: %d)", g_pxstate.command, (int)pid); - /* Close our copies of the pipes that we don't need */ - close(pipe_e[WRITE_END]); - pipe_e[WRITE_END] = -1; + /* Setup all our return values */ + if(infd) + { + *infd = pipe_i[WRITE_END]; + pipe_i[WRITE_END] = -1; + fcntl(*infd, F_SETFL, fcntl(*infd, F_GETFL, 0) | O_NONBLOCK); + } - /* Pipe shouldn't be blocking */ - fcntl(pipe_e[READ_END], F_SETFL, fcntl(pipe_e[READ_END], F_GETFL, 0) | O_NONBLOCK); + if(outfd) + { + *outfd = pipe_o[READ_END]; + pipe_o[READ_END] = -1; + fcntl(*outfd, F_SETFL, fcntl(*outfd, F_GETFL, 0) | O_NONBLOCK); + } + + if(errfd) + { + *errfd = pipe_e[READ_END]; + pipe_e[READ_END] = -1; + fcntl(*errfd, F_SETFL, fcntl(*errfd, F_GETFL, 0) | O_NONBLOCK); + } + +cleanup: + if(pipe_i[READ_END] != -1) + close(pipe_i[READ_END]); + if(pipe_i[WRITE_END] != -1) + close(pipe_i[WRITE_END]); + if(pipe_o[READ_END] != -1) + close(pipe_o[READ_END]); + if(pipe_o[WRITE_END] != -1) + close(pipe_o[WRITE_END]); + if(pipe_e[READ_END] != -1) + close(pipe_e[READ_END]); + if(pipe_e[WRITE_END] != -1) + close(pipe_e[WRITE_END]); + + return ret >= 0 ? pid : (pid_t)-1; +} + +static int process_file_command(spctx_t* sp) +{ + pid_t pid; + int ret = 0, status, r; + struct timeval timeout; + + /* For reading data from the process */ + int errfd; + fd_set rmask; + char obuf[1024]; + char ebuf[256]; + + memset(ebuf, 0, sizeof(ebuf)); + + if(sp_cache_data(sp) == -1) + RETURN(-1); /* message already printed */ + + pid = fork_filter(sp, NULL, NULL, &errfd); + if(pid == (pid_t)-1) + RETURN(-1); /* Main read write loop */ - for(;;) + while(errfd != -1) { FD_ZERO(&rmask); - FD_SET(pipe_e[READ_END], &rmask); + FD_SET(errfd, &rmask); - r = select(FD_SETSIZE, &rmask, NULL, NULL, &(g_pxstate.timeout)); + /* Select can modify the timeout argument so we copy */ + memcpy(&timeout, &(g_pxstate.timeout), sizeof(timeout)); + + r = select(FD_SETSIZE, &rmask, NULL, NULL, &timeout); switch(r) { @@ -370,43 +450,46 @@ static int process_file_command(spctx_t* sp) RETURN(-1); }; - for(;;) + ASSERT(FD_ISSET(errfd, &rmask)); + + /* Note because we handle as string we save one byte for null-termination */ + r = read(errfd, obuf, sizeof(obuf) - 1); + if(r < 0) { - /* Note because we handle as string we save one byte for null-termination */ - r = read(pipe_e[READ_END], obuf, sizeof(obuf) - 1); - if(r < 0) + if(errno != EINTR && errno != EAGAIN) { - if(errno != EINTR && errno != EAGAIN) - { - sp_message(sp, LOG_ERR, "couldn't read data from filter command"); - RETURN(-1); - } - - break; + sp_message(sp, LOG_ERR, "couldn't read data from filter command"); + RETURN(-1); } - if(r == 0) - break; - - /* Null terminate */ - obuf[r] = 0; - - /* And process */ - buffer_reject_message(obuf, ebuf, sizeof(ebuf)); + continue; } - /* Check if process is still around */ - if(waitpid(pid, &status, WNOHANG) == pid) + if(r == 0) { - pid = 0; + close(errfd); + errfd = -1; break; } + /* Null terminate */ + obuf[r] = 0; + + /* And process */ + buffer_reject_message(obuf, ebuf, sizeof(ebuf)); + if(sp_is_quit()) - break; + RETURN(-1); + } + + /* exit the process if not completed */ + if(wait_process(sp, pid, &status) == -1) + { + sp_messagex(sp, LOG_ERR, "timeout waiting for filter command to exit"); + RETURN(-1); } - ASSERT(pid == 0); + pid = 0; /* We only trust well behaved programs */ if(!WIFEXITED(status)) @@ -441,17 +524,15 @@ static int process_file_command(spctx_t* sp) cleanup: - if(pipe_e[READ_END] != -1) - close(pipe_e[READ_END]); - if(pipe_e[WRITE_END] != -1) - close(pipe_e[WRITE_END]); - if(pid != 0) { sp_messagex(sp, LOG_WARNING, "killing filter process (pid %d)", (int)pid); kill_process(sp, pid); } + if(errfd != -1) + close(errfd); + if(ret < 0) sp_add_log(sp, "status=", "FILTER-ERROR"); @@ -461,125 +542,56 @@ cleanup: static int process_pipe_command(spctx_t* sp) { pid_t pid; - int ret = 0, status; - int r, n, done; + int ret = 0, status, r; + struct timeval timeout; /* For sending data to the process */ const char* ibuf = NULL; int ilen = 0; - int pipe_i[2]; + int infd; + int icount = 0; fd_set wmask; - int writing; /* For reading data from the process */ - int pipe_o[2]; - int pipe_e[2]; + int outfd; + int errfd; fd_set rmask; - int reading; char obuf[1024]; char ebuf[256]; + int ocount = 0; ASSERT(g_pxstate.command); memset(ebuf, 0, sizeof(ebuf)); - memset(pipe_i, ~0, sizeof(pipe_i)); - memset(pipe_o, ~0, sizeof(pipe_o)); - memset(pipe_e, ~0, sizeof(pipe_e)); - - /* Create the pipes we need */ - if(pipe(pipe_i) == -1 || pipe(pipe_o) == -1 || pipe(pipe_e) == -1) - { - sp_message(sp, LOG_ERR, "couldn't create pipes for filter command"); + pid = fork_filter(sp, &infd, &outfd, &errfd); + if(pid == (pid_t)-1) RETURN(-1); - } - /* Now fork the pipes across processes */ - switch(pid = fork()) - { - case -1: - sp_message(sp, LOG_ERR, "couldn't fork for filter command"); - RETURN(-1); - - /* The child process */ - case 0: - - /* Close our unused ends of the pipes */ - close(pipe_i[WRITE_END]); - close(pipe_o[READ_END]); - close(pipe_e[READ_END]); - - /* Fixup our ends of the pipe */ - if(dup2(pipe_i[READ_END], STDIN) == -1 || - dup2(pipe_o[WRITE_END], STDOUT) == -1 || - dup2(pipe_e[WRITE_END], STDERR) == -1) - { - sp_message(sp, LOG_ERR, "couldn't dup descriptors for filter command"); - _exit(1); - } - - /* All the necessary environment vars */ - sp_setup_forked(sp, 0); - - /* Now run the filter command */ - execl("/bin/sh", "sh", "-c", g_pxstate.command, NULL); - - /* If that returned then there was an error */ - sp_message(sp, LOG_ERR, "error executing the shell for filter command"); - _exit(1); - break; - }; - - /* The parent process */ - sp_messagex(sp, LOG_DEBUG, "executed filter command: %s (pid: %d)", g_pxstate.command, (int)pid); - - /* Close our copies of the pipes that we don't need */ - close(pipe_i[READ_END]); - pipe_i[READ_END] = -1; - close(pipe_o[WRITE_END]); - pipe_o[WRITE_END] = -1; - close(pipe_e[WRITE_END]); - pipe_e[WRITE_END] = -1; - - /* None of our pipes should be blocking */ - fcntl(pipe_i[WRITE_END], F_SETFL, fcntl(pipe_i[WRITE_END], F_GETFL, 0) | O_NONBLOCK); - fcntl(pipe_o[READ_END], F_SETFL, fcntl(pipe_o[READ_END], F_GETFL, 0) | O_NONBLOCK); - fcntl(pipe_e[READ_END], F_SETFL, fcntl(pipe_e[READ_END], F_GETFL, 0) | O_NONBLOCK); + /* Opens cache file */ + if(sp_write_data(sp, obuf, 0) == -1) + RETURN(-1); /* message already printed */ /* Main read write loop */ - for(;;) + while(infd != -1 || outfd != -1 || errfd != -1) { - reading = 0; - writing = 0; - done = 0; - FD_ZERO(&rmask); FD_ZERO(&wmask); /* We only select on those that are still open */ - if(pipe_i[WRITE_END] != -1) - { - FD_SET(pipe_i[WRITE_END], &wmask); - writing = 1; - } - if(pipe_o[READ_END] != -1) - { - FD_SET(pipe_o[READ_END], &rmask); - reading = 1; - } - if(pipe_e[READ_END] != -1) - { - FD_SET(pipe_e[READ_END], &rmask); - reading = 1; - } + if(infd != -1) + FD_SET(infd, &wmask); - /* If nothing open then go away */ - if(!reading && !writing) - break; + if(outfd != -1) + FD_SET(outfd, &rmask); - r = select(FD_SETSIZE, reading ? &rmask : NULL, - writing ? &wmask : NULL, NULL, &(g_pxstate.timeout)); + if(errfd != -1) + FD_SET(errfd, &rmask); + /* Select can modify the timeout argument so we copy */ + memcpy(&timeout, &(g_pxstate.timeout), sizeof(timeout)); + + r = select(FD_SETSIZE, &rmask, &wmask, NULL, &timeout); switch(r) { case -1: @@ -591,7 +603,7 @@ static int process_pipe_command(spctx_t* sp) }; /* Handling of process's stdin */ - if(FD_ISSET(pipe_i[WRITE_END], &wmask)) + if(infd != -1 && FD_ISSET(infd, &wmask)) { if(ilen <= 0) { @@ -599,9 +611,10 @@ static int process_pipe_command(spctx_t* sp) switch(r = sp_read_data(sp, &ibuf)) { case -1: - RETURN(-1); /* Message already printed */ + RETURN(-1); /* Message already printed */ case 0: - done = 1; + close(infd); /* Done with the input */ + infd = -1; break; default: ASSERT(r > 0); @@ -610,131 +623,118 @@ static int process_pipe_command(spctx_t* sp) }; } - /* Write data from buffer */ - r = write(pipe_i[WRITE_END], ibuf, ilen); - if(r == -1) + if(ilen > 0) { - if(errno == EPIPE) + /* Write data from buffer */ + r = write(infd, ibuf, ilen); + if(r == -1) { - sp_messagex(sp, LOG_WARNING, "filter command closed input early"); + if(errno == EPIPE) + { + sp_messagex(sp, LOG_WARNING, "filter command closed input early"); - /* Eat up the rest of the data */ - while(sp_read_data(sp, &ibuf) > 0) - ; - done = 1; - break; + /* Eat up the rest of the data */ + while(sp_read_data(sp, &ibuf) > 0) + ; + + close(infd); + infd = -1; + break; + } + else if(errno != EAGAIN && errno != EINTR) + { + /* Otherwise it's a normal error */ + sp_message(sp, LOG_ERR, "couldn't write to filter command"); + RETURN(-1); + } } - else if(errno != EAGAIN && errno != EINTR) + + /* A good normal write */ + else { - /* Otherwise it's a normal error */ - sp_message(sp, LOG_ERR, "couldn't write to filter command"); - RETURN(-1); + icount += r; + ilen -= r; + ibuf += r; } } - - /* A good normal write */ - else - { - ilen -= r; - ibuf += r; - } } - /* Check if process is still around */ - if(!done && waitpid(pid, &status, WNOHANG) == pid) + /* Handling of stdout, which should be email data */ + if(outfd != -1 && FD_ISSET(outfd, &rmask)) { - pid = 0; - done = 1; - } - - /* Close output pipes if done */ - if(done) - { - close(pipe_i[WRITE_END]); - pipe_i[WRITE_END] = -1; + r = read(outfd, obuf, sizeof(obuf)); + if(r > 0) + { + if(sp_write_data(sp, obuf, r) == -1) + RETURN(-1); /* message already printed */ - /* Force emptying of these guys */ - FD_SET(pipe_o[READ_END], &rmask); - FD_SET(pipe_e[READ_END], &rmask); - } + ocount += r; + } - /* - * During normal operation we only read one block of data - * at a time, but once done we make sure to drain the - * output buffers dry. - */ - do - { - /* Handling of stdout, which should be email data */ - if(FD_ISSET(pipe_o[READ_END], &rmask)) + else if(r == 0) { - r = read(pipe_o[READ_END], obuf, sizeof(obuf)); - if(r > 0) - { - if(sp_write_data(sp, obuf, r) == -1) - RETURN(-1); /* message already printed */ - } + close(outfd); + outfd = -1; + } - else if(r < 0) + else if(r < 0) + { + if(errno != EINTR && errno != EAGAIN) { - if(errno != EINTR && errno != EAGAIN) - { - sp_message(sp, LOG_ERR, "couldn't read data from filter command"); - RETURN(-1); - } + sp_message(sp, LOG_ERR, "couldn't read data from filter command"); + RETURN(-1); } } + } - /* Handling of stderr, the last line of which we use as an err message*/ - if(FD_ISSET(pipe_e[READ_END], &rmask)) + /* Handling of stderr, the last line of which we use as an err message*/ + if(errfd != -1 && FD_ISSET(errfd, &rmask)) + { + /* Note because we handle as string we save one byte for null-termination */ + r = read(errfd, obuf, sizeof(obuf) - 1); + if(r < 0) { - /* Note because we handle as string we save one byte for null-termination */ - n = read(pipe_e[READ_END], obuf, sizeof(obuf) - 1); - if(n < 0) + if(errno != EINTR && errno != EAGAIN) { - if(errno != EINTR && errno != EAGAIN) - { - sp_message(sp, LOG_ERR, "couldn't read data from filter command"); - RETURN(-1); - } + sp_message(sp, LOG_ERR, "couldn't read data from filter command"); + RETURN(-1); } + } - else if(n > 0) - { - /* Null terminate */ - obuf[n] = 0; - - /* And process */ - buffer_reject_message(obuf, ebuf, sizeof(ebuf)); - } + else if(r == 0) + { + close(errfd); + errfd = -1; } - } /* when in 'done' mode we keep reading as long as there's data */ - while(done && (r > 0 || n > 0)); + else if(r > 0) + { + /* Null terminate */ + obuf[r] = 0; - if(done) - break; + /* And process */ + buffer_reject_message(obuf, ebuf, sizeof(ebuf)); + } + } if(sp_is_quit()) - break; + RETURN(-1); } + sp_messagex(sp, LOG_DEBUG, "wrote %d bytes to filter, read %d bytes", icount, ocount); + /* Close the cache file */ if(sp_write_data(sp, NULL, 0) == -1) RETURN(-1); /* message already printed */ - /* exit the process if not completed */ - if(pid != 0) + if(wait_process(sp, pid, &status) == -1) { - if(wait_process(sp, pid, &status) == -1) - { - sp_messagex(sp, LOG_ERR, "timeout waiting for filter command to exit"); - RETURN(-1); - } - - pid = 0; + sp_messagex(sp, LOG_ERR, "timeout waiting for filter command to exit"); + RETURN(-1); } + pid = 0; + /* We only trust well behaved programs */ if(!WIFEXITED(status)) { @@ -768,18 +768,12 @@ static int process_pipe_command(spctx_t* sp) cleanup: - if(pipe_i[READ_END] != -1) - close(pipe_i[READ_END]); - if(pipe_i[WRITE_END] != -1) - close(pipe_i[WRITE_END]); - if(pipe_o[READ_END] != -1) - close(pipe_o[READ_END]); - if(pipe_o[WRITE_END] != -1) - close(pipe_o[WRITE_END]); - if(pipe_e[READ_END] != -1) - close(pipe_e[READ_END]); - if(pipe_e[WRITE_END] != -1) - close(pipe_e[WRITE_END]); + if(infd != -1) + close(infd); + if(outfd != -1) + close(outfd); + if(errfd != -1) + close(errfd); if(pid != 0) { |