diff options
Diffstat (limited to 'local.c')
| -rw-r--r-- | local.c | 238 |
1 files changed, 238 insertions, 0 deletions
@@ -0,0 +1,238 @@ +/** + * \file local.c + * Local delivery of mail via a MDA. + */ + + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <signal.h> +#include <pwd.h> + +#include "local.h" +#include "main.h" + + +#if 0 +char *mda = NULL; +#else +char *mda = "/usr/bin/procmail -d %T"; +#endif + +FILE *mda_fp = NULL; + + +int local_address(const char *address) +{ + return !strchr(address, '@'); +} + +/** replace ' by _ */ +static void sanitize(char *s) +{ + char *cp; + + for (cp = s; (cp = strchr (cp, '\'')); cp++) + *cp = '_'; +} + +#define xmalloc malloc +#define xstrdup strdup + +#define HAVE_SETEUID + +/** + * Pipe the message to the MDA for local delivery. + * + * Based on fetchmail's open_mda_sink(). + */ +int local_init(message_t *message) +{ +#ifdef HAVE_SETEUID + uid_t orig_uid, uid; + struct passwd *pw; +#endif /* HAVE_SETEUID */ + struct idlist *idp; + int length = 0, fromlen = 0, nameslen = 0; + char *names = NULL, *before, *after, *from = NULL; + char *user = NULL; + + if (!mda) + return 1; + + length = strlen(mda); + before = xstrdup(mda); + + /* get user addresses for %T */ + if (strstr(before, "%T")) + { + struct list_head *ptr; + + /* + * We go through this in order to be able to handle very + * long lists of users and (re)implement %s. + */ + nameslen = 0; + list_for_each(ptr, &message->local_recipients) + { + recipient_t *recipient = list_entry(ptr, recipient_t, list); + + if(recipient->address) + nameslen += (strlen(recipient->address) + 1); /* string + ' ' */ + } + + names = (char *)xmalloc(nameslen + 1); /* account for '\0' */ + names[0] = '\0'; + list_for_each(ptr, &message->local_recipients) + { + recipient_t *recipient = list_entry(ptr, recipient_t, list); + + if(recipient->address) + { + if(!user) + user = recipient->address; + strcat(names, recipient->address); + strcat(names, " "); + } + } + names[--nameslen] = '\0'; /* chop trailing space */ + + sanitize(names); + } + + /* get From address for %F */ + if (strstr(before, "%F")) + { + from = xstrdup(message->reverse_path); + + sanitize(from); + + fromlen = strlen(from); + } + + /* do we have to build an mda string? */ + if (names || from) + { + char *sp, *dp; + + /* find length of resulting mda string */ + sp = before; + while ((sp = strstr(sp, "%s"))) { + length += nameslen; /* subtract %s and add '' */ + sp += 2; + } + sp = before; + while ((sp = strstr(sp, "%T"))) { + length += nameslen; /* subtract %T and add '' */ + sp += 2; + } + sp = before; + while ((sp = strstr(sp, "%F"))) { + length += fromlen; /* subtract %F and add '' */ + sp += 2; + } + + after = xmalloc(length + 1); + + /* copy mda source string to after, while expanding %[sTF] */ + for (dp = after, sp = before; (*dp = *sp); dp++, sp++) { + if (sp[0] != '%') continue; + + /* need to expand? BTW, no here overflow, because in + ** the worst case (end of string) sp[1] == '\0' */ + if (sp[1] == 'T') { + *dp++ = '\''; + strcpy(dp, names); + dp += nameslen; + *dp++ = '\''; + sp++; /* position sp over [sT] */ + dp--; /* adjust dp */ + } else if (sp[1] == 'F') { + *dp++ = '\''; + strcpy(dp, from); + dp += fromlen; + *dp++ = '\''; + sp++; /* position sp over F */ + dp--; /* adjust dp */ + } + } + + if (names) { + free(names); + names = NULL; + } + if (from) { + free(from); + from = NULL; + } + + free(before); + + before = after; + } + +#ifdef HAVE_SETEUID + /* + * Arrange to run with user's permissions if we're root. + * This will initialize the ownership of any files the + * MDA creates properly. (The seteuid call is available + * under all BSDs and Linux) + */ + orig_uid = getuid(); + /* if `user' doesn't name a real local user, try to run as root */ + if ((pw = getpwnam(user)) == (struct passwd *)NULL) + uid = 0; + else + uid = pw->pw_uid; /* for local delivery via MDA */ + seteuid(uid); +#endif /* HAVE_SETEUID */ + + mda_fp = popen(before, "w"); + +#ifdef HAVE_SETEUID + /* this will fail quietly if we didn't start as root */ + seteuid(orig_uid); +#endif /* HAVE_SETEUID */ + + if (!mda_fp) + { + free(before); + before = NULL; + fprintf(stderr, "MDA open failed\n"); + return 0; + } + + if(verbose) + fprintf(stdout, "Connected to MDA: %s\n", before); + + free(before); + before = NULL; + return 1; +} + +int local_flush(message_t *message) +{ + char buffer[BUFSIZ]; + size_t n; + + do { + n = message_read(message, buffer, BUFSIZ); + if(fwrite(buffer, 1, n, mda_fp) != n) + return 0; + } while(n == BUFSIZ); + + return 1; +} + +void local_cleanup(void) +{ + if(mda_fp) + { + fclose(mda_fp); + mda_fp = NULL; + + if(verbose) + fprintf(stdout, "Disconnected to MDA\n"); + } +} |